Use of type I bovine collagen membranes for treating deep and perforating corneal ulcers in brachycephalic dogs

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Acevedo, Nathalia M. Correa-Valencia This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6733977/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 30 Jul, 2025 Read the published version in Veterinary Research Communications → Version 1 posted 7 You are reading this latest preprint version Abstract This retrospective study aimed to assess the effectiveness of 200 µm type I bovine skin-derived collagen membranes in treating deep and penetrating corneal ulcers in dogs. Twelve cases involving dogs with descemetocele and/or ocular perforation demonstrated advanced corneal stromal damage and compromised eye integrity. Two hundred-micrometer (200 µm) type I bovine skin-derived collagen membranes were inserted into the corneal lesion, which was protected with a 360-degree conjunctival flap, followed by tarsorrhaphy. Evaluations were conducted on days 15, 30, and 60 via a self-designed V-injury score scale. By day 15, patients exhibited significant improvement, with stable intraocular pressure (IOP) and the absence of pain. All patients displayed episcleritis, moderate conjunctival inflammation, and diffuse corneal edema. The score was II in 10 dogs without limbal involvement but with moderate edema. Two dogs had a Grade III injury score with corneal edema exceeding 50% and moderate limbal involvement. By day 30, all patients had remodeled the corneal defect with stable IOPs, but three had moderate edema and superficial vascularization. On day 60, stable IOPs were observed, with four patients developing simple leucoma without involvement with the visual axis or active corneal alteration. The use of 200 µm type I bovine skin-derived collagen membranes, with a 360-degree conjunctival flap and temporary tarsorrhaphy, proves to be an excellent adjuvant in the healing process of deep and perforating corneal lesions in dogs. This combination facilitates corneal remodeling, reducing adverse scarring. Cornea Collagen Descemetocele Corneal Perforation Leucoma Re-Epithelialization Figures Figure 1 Figure 2 Background Corneal ulcers represent one of the most prevalent reasons for ophthalmological consultations in routine veterinary clinics for both dogs and cats. Characterized by a disruption in the integrity of the corneal epithelial layer, these ulcers initially present as corneal erosion, involving superficial epithelial disruption without stromal damage. If complications ensue, the ulceration may advance to a descemetocele, reaching through the cornea and stroma to the levels of Descemet's membrane. In more severe instances, complete perforation, extending across all layers of the cornea, can occur (Gelatt et al. 2022a , b ). Such outcomes can lead to visual impairments and, in more critical scenarios, may be complicated by intraocular infection, ultimately resulting in total loss of ocular structure. This progression is attributed to the release of proteolytic enzymes and toxins. Therefore, early diagnosis and effective treatment are imperative to prevent complications such as corneal perforation and alterations in transparency (Whitley 2000 ). While most corneal defects resolve without complications, epithelial wound healing can be impeded by various pathological factors, leading to persistent epithelial defects and stromal thinning. The traditional treatment for such defects centers on addressing the underlying disease mechanism, controlling inflammation, and safeguarding the corneal surface. Nevertheless, many corneal defects, especially those that are deep and stromal, do not respond to this therapeutic approach. This lack of responsiveness can escalate to imminent perforation, primarily due to bacterial contamination and ocular trauma (Herrera 2007 ). The response to treatment may prompt the consideration of surgical options to address the resulting defect. Conjunctival plasty techniques have emerged as valuable tools in the regeneration of deep and perforating corneal injuries, offering significant healing effects through tissue fixation. However, it is important to note that such techniques can also be associated with the formation of granulation tissue, potentially impacting the surgical result (Meneses and Serna 2000 ; Peña and Leiva 2012 ). This effect is attributed mainly to local alterations that can occur during the healing process. Traditional surgical techniques for managing deep corneal and descemetocele ulcers include the third eyelid flap, 180° flap, 360° flap, and pedicle flap. These procedures involve the utilization of supporting tissue from the conjunctiva to facilitate epithelial regeneration and repair. In addition, the use of biologic membrane implants derived from allogeneic or xenogeneic sources represents a significant alternative for treating corneal ulcerative and perforating lesions. These implants aim not only to address the primary lesion but also to promote the formation of innocuous scar tissue that minimally impacts corneal transparency and, consequently, visual capacity (Wiemer et al. 2005 ). Considering the evolving landscape of veterinary ophthalmology in recent decades, understanding corneal ulcers and their treatment has become essential. Consequently, this report aims to assess the effectiveness of 200 µm type I bovine skin-derived collagen membranes in the treatment of deep and penetrating corneal ulcers in dogs. Case presentation This report presents a descriptive study comprising 12 cases in dogs treated at the Ocularvet Ophthalmological Unit in the city of Medellín (Antioquia, Colombia). The study population consisted of 12 patients characterized by breed, sex, and age. Among them were a French bulldog male, 8 years old (patient 1); an American bulldog male, 6 years old (patient 2); a French bulldog female, 2 years old (patient 3); and another French bulldog female, 4 years old (patient 4). The group also included a crossbred (American Bulldog × Bully) male, 5 years old (patient 5); a Boston Terrier female, 3 years old (patient 6); a Shih Tzu male, 2 years old (patient 7); and another Shih Tzu male, 3 years old (patient 8). Additionally, there was a Bulldog male, 2 years old (patient 9); a Shih Tzu female, 2 years old (patient 10); another Shih Tzu female, 4 years old (patient 11); and finally, a Shih Tzu male, 8 years old (patient 12). These patients were diagnosed with descemetocele (deep ulcer) and/or ocular perforation, indicating advanced damage to the corneal stroma that was refractory to intensive medical therapy, resulting in compromised eye integrity. The V-injury score scale, as outlined in Table 1 , was applied both before and after surgery under the guidance of the treating veterinary ophthalmologist. A comprehensive ophthalmological evaluation was conducted utilizing a portable slit lamp (Kowa SL-19®, Kowa Co., Ltd., Tokyo, Japan) to ascertain the depth of the lesion. Fluorescein and, when necessary, Seidel tests were performed. Lesion size and associated signs, such as corneal edema and ciliary vascularization, were measured millimetrically via a direct ophthalmoscope (Welch Allyn 11720®, Welch Allyn Co., USA). IOP was measured via applanation tonometry with a Tono-pen Vet™ device (Reichert Metek. NY, USA) via applanation-based technology, which employs micro strain gauge technology and a 1.0 mm-diameter transducer tip. Table 1 The V-injury score scale used both before and after surgery Grade Description I The prognosis is very good, as the lesion is solely located in the cornea with no synechia. There is no presence of neovascularization or corneal edema II The prognosis is good, with no synechia observed. However, there is moderate corneal edema, accompanied by the superficial presence of vessels III Reserved prognosis with moderate synechia with brush vascularization, and corneal edema exceeding 50% IV Reserved prognosis due to marked synechia, generalized neovascularization, and significant corneal edema V Poor prognosis with complete conjunctival and limbal involvement, generalized neovascularization, dense scleral vessel infiltration, hypotonic eye, and potential epithelial, stromal, and Descemet's membrane involvement Clinical findings revealed that patients experienced marked ocular pain related to corneal injury, ocular hypotonia due to secondary uveitis, and, in some cases, diffuse corneal edema and corneal vascularization. Examination of the ocular fundus via both direct (optical diopters of 0 and − 1) (Welch Allyn 11720®, Welch Allyn Co., USA) and indirect (optical diopter of 22) (Keeler Vantage®, Keeler Vantage Co., USA) ophthalmoscopies were challenging because of corneal opacity and inflammation in the anterior uvea, resulting in a positive Tyndall effect for uveitis response. Patients exhibit symptoms such as loss of appetite, behavioral changes (e.g., aggression, apathy), sudden rubbing of the affected eye, and, in some cases, mucoid secretion. Additionally, visual deficits associated with corneal lesions or opacities, along with possible miosis due to uveitis, were noted. This pathology is considered an emergency, requiring surgical intervention within the next 12 hours. For the insertion of the 360-degree conjunctival flap, neuroleptanalgesia was administered to all patients via tramadol (Tramal®, Laboratorios Genfar, Bogotá, Colombia) at a rate of 3 mg/kg BW and acepromazine (Acedan®, Laboratorio Holliday, Buenos Aires, Argentina) at 0.3 mg/kg BW, IM. The surgical procedure was conducted under general anesthesia, with 1% propofol induction (Propofol al 1%®, Braun, Bogotá, Colombia) at 5 mg/kg BW, IV, and maintenance with isoflurane (Isoflorano®, Laboratorio Baxter, Cali, Colombia) at 5 mg/kg BW. A muscle relaxant was administered during the procedure to facilitate centering of the eyeball (rocuronium; Rocuronio bromuro®, Vitalis, Quito, Ecuador, at 0.02 mg/kg BW, administered slowly IV). All surgeries were performed by the same surgeon. Each of the 12 canine patients underwent surgical insertion of a 200 µm type I bovine skin-derived collagen membrane, exclusively for veterinary use (Collagen Membrane®, AJL Ophthalmic S.A., Álava, Spain), into the corneal lesion via surgical nylon (Ethylon 9 − 0®, Ethalloy, Bogotá, Colombia) with simple stitches (between 14 and 16). The surface was protected with a 360-degree conjunctival flap using polydactin (Vicryl 5 − 0®, Ethalloy, Bogotá, Colombia) with U stitches (four) and temporary tarsorrhaphy using surgical nylon (Corpalon 4 − 0®, Master Medical, Bogotá, Colombia) with U points (two). The conjunctival flap and temporary tarsorrhaphy were employed to safeguard the membrane, preventing the loss of tension or denaturation before the healing period. Briefly, the membrane was hydrated for 20 minutes in a balanced salt solution under aseptic conditions. The initial disinfection of the affected eye involved the corneal and periocular application of 1% povidone-iodine. In cases with limbal perforation, paracentesis was performed via a 12–15-degree ophthalmic knife at the 12:00–14:00 circle position (depending on the lesion). A 2% hyaluronate cohesive viscoelastic mixture was applied to reinforce the chamber, especially in patients with atlamydia. For cases with perforation and staphyloma, the same procedure was performed, along with iris repositioning (i.e., moving the iris to its correct position) in specific cases (Patients 1, 6, 10, 11, and 12). If an exposed staphyloma was identified (5 out of 12 patients) a protrusion or bulging of weakened ocular tissue, typically the uveal tissue (choroid and retina) or sclera, that becomes externally visible owing to thinning or loss of the overlying structures, such as the conjunctiva or cornea. This defect was removed, and the chamber was repaired before membrane placement. In addition, a single dose of cefovecin sodium (Convenia®, Zoetis, Parsippany, NJ, USA) was administered intraoperatively at 8 mg/kg BW, SC. In each case, the membrane was positioned on the corneal defect, ensuring that the smooth face of the graft aligned with the affected cornea. Subsequently, through the same limbal paracentesis, a balanced saline solution was infused via a Simcoe cannula, the viscoelastic device was aspirated, and the solution was left in the anterior chamber. The graft was then hydrated with drops of balanced saline solution, and accommodation was performed via an iris spatula. Simple stitches were used for attachment, employing nonabsorbable material (Ethylon 9 − 0®, Ethalloy, Bogotá, Colombia) in two patients (1 and 4) and polyglycolic acid (8 − 0) in the others, owing to material availability issues. Sutures were placed around the graft and secured to the healthy cornea (2–3 mm from the defect), ensuring attachment and confirming the absence of aqueous humor leakage in cases of perforation. This procedure effectively covered the entire corneal defect. After surgery, the postoperative treatment for all patients included the use of an Elizabeth collar, along with ciprofloxacin plus chondroitin sulfate eye drops (Ciprovet®, Labyes, Morón, Argentina). One eye drop was administered to the operated eye every 8 hours for the initial 15 days, followed by every 12 hours for the subsequent 15 days, and finally, every 24 hours for the remaining 15 days, completing a 45-day treatment. In addition, sodium hyaluronate plus chondroitin sulfate eye drops (Humylub Ofteno Pf®, Laboratorios Sophia de Colombia Ltda.) were applied every 8 hours to the operated eye for a duration of 2 months. Oral meloxicam drops (Meloxic®, Laboratorios Provet, Bogotá, Colombia) at a rate of 0.1 mg/kg BW were administered every 24 hours for 3 days. The eye drops were applied on the 360-degree conjunctival flap through the narrow temporal tarsorrhaphy opening for the initial 15 days. From day 16 to day 60, eye drops were applied to the cornea through normal eyelid opening. Each patient underwent evaluations on day 15, involving the removal of the tarsorrhaphy and conjunctival plasty sutures. Subsequent evaluations were conducted on days 30 and 60 after surgery, and the presence/absence of an active corneal ulcer was assessed via a fluorescein test. Measurements of the size of the corneal opacity (in mm), presence/absence of superficial and deep vessels, presence/absence of granulation tissue, threat response, and ocular fundus evaluation were performed through a complete ophthalmological examination (when possible, given the conditions in which the patients arrived). The IOP was assessed as previously described. For the removal of the 360-degree conjunctival flap, neuroleptanalgesia was administered to all patients as described previously. In addition, a topical proximetacaine (Alcaine®, Laboratorios Alcon. Bogotá, Colombia) was applied, and the sutures were removed with a magnifying glass, and the dose of proparacaine was repeated if necessary. Successful results to treatment were defined as those eyes with stable IOPs between 15 and 25 mmHg whose corneal lesions presented total re-epithelialization (negative fluorescein test and Seidel test) at the time of evaluation. In addition, the recovery of corneal transparency was evaluated at each moment, defined according to the decrease in corneal edema and the presence/absence of corneal superficial and deep vessels, as well as the size of the corneal scar (leucoma) and ocular fundus examination. An injury description was defined both before and after surgery (Shin et al. 2033). Table 2 illustrates the progression of patients based on the V-injury score scale and the follow-up of IOP. Clinical examinations and IOP measurements were conducted for each patient on days 15, 30, and 60 after surgery. In the initial measurements during surgery, all patients presented decreased IOP associated with ocular perforation. Aqueous humor loss was observed in four patients (4, 6, 9, and 10), whereas the other two patients (7 and 8) with deep ulcers had active uveitis. On day 15 after surgery, upon suture removal, notable improvement was observed, with stable IOPs and no signs of pain on palpation. Episcleritis and moderate conjunctival inflammation persisted in all patients due to the corneal regeneration process and 360-degree conjunctival flap removal. The injury score at this point was II in 10 patients (2, 3, 4, 5, 6, 7, 9, 10, 11, and 12), indicating a good prognosis with no limbal involvement, superficial vessels, and moderate edema. One patient still had more than 50% corneal edema and limbal involvement, although in the process of corneal remodeling. Notably, this patient arrived at the clinic with severe corneal perforation already affecting the visual axis at the time of surgery. Thirty days after surgery, all patients remodeled the corneal defect with stable IOPs, and there were no active ulcers. Two patients (1 and 4), who initially presented with perforation, still had moderate edema and superficial vascularization. By day 60, all patients maintained stable IOPs. Four patients (2, 4, 7, and 8) presented simple leucoma without visual axis involvement or active corneal alteration. Only one patient, who initially experienced perforation, still exhibited moderate edema and superficial vessels but without an active lesion. Adequate corneal re-epithelialization was confirmed in all patients, with varying degrees of scarring. A threat response was observed in all patients at the time of evaluation, and total or partial exploration of the ocular fundus was conducted since the density of the leucoma. Table 2 Characterization of the affected eyes at the time of surgery and follow-up on days 15, 30, and 60 after surgery Patient Lesion at the time of surgery IOP at the time of surgery (in mmHg) Injury score at the time of surgery * IOP − 15 days of evolution (in mmHg) Injury score − 15 days of evolution * IOP − 30 days of evolution (in mmHg) Injury score − 30 days of evolution * IOP − 60 days of evolution (in mmHg) Injury score − 60 days of evolution * 1 Perforating 9 V 14 III 20 II 20 II 2 Profound 14 III 17 II 17 I 17 Leukoma 3 Profound 14 III 16 II 17 I 17 I 4 Perforating 10 IV 14 II 17 I 17 Leukoma 5 Profound 15 IV 15 II 15 I 15 I 6 Perforating 11 V 19 II 20 II Not determined Not determined 7 Profound 13 III 16 II 17 I 18 Leukoma 8 Profound 12 V 15 III 16 II 16 Leukoma 9 Perforating 9 IV 12 II 14 I 18 II 10 Perforating 10 IV 15 II 18 I 20 II 11 Perforating 8 IV 14 II 18 I 20 I 12 Perforating 10 IV 15 II 18 I 21 I IOP: Intraocular pressure. *According to a self-designed V- injury score scale. Photographic evidence of two patients' processes is presented (2 and 4), showing the conditions before (A) and after membrane application (B), as well as evaluations at different postsurgery time points (C, D, and E for 15, 30, and 60 days, respectively, and when applied). Figure 1 illustrates the specific evolution of patient 2, who faced a challenging prognosis with ocular perforation, severe corneal edema, and intracameral inflammation. The sequence of images provides a comprehensive visual representation of the patient's progress, revealing the stages from the initial condition to the eventual improvement with the applied treatment. Satisfactory results were achieved, showing extensive corneal regeneration and simple leucoma for such deep lesions, leading to visual recovery. Figure 2 shows the specific evolution of patient 4, which was characterized by notable and remarkable corneal regeneration. A simple leucoma developed without affecting the visual axis, despite the initial presentation of a deep ulcer with significant corneal inflammation and generalized edema. The images illustrate the step-by-step progress of Patient 4, capturing key moments from the initial condition to the final stage of the healing process. Regrettably, patient 6 passed away before the 60-day postsurgery review, which was attributed to nonocularly related causes. The photographic follow-up data for all 12 patients are available at https://postimg.cc/gallery/YjWyDGm . B. Membrane adhered to the cornea. C. Adequate corneal healing with 90% moderate granulation tissue, without iridal exposure. D. Moderate leucoma and phantom vessels, with adequate corneal remodeling. E. Simple leucoma, ensuring an adequate visual axis Patients with corneal injury scores of I or II at 60 days after surgery (patients 1, 3, 5, 6, 9, and 10) received a therapy regimen comprising 1% cyclosporine eye drops (a master formula, distributed by Oftasalud S.A.S., Bogotá, Colombia) every 12 hours for 30 days, along with heterologous serum every 8 hours for 15 days. Satisfactory results were achieved, with recovery of corneal transparency in all patients who received the latter treatment. For other patients, the use of cyclosporine was not considered, as posthealing opacity was minimal and did not affect the visual axis. Although the leucoma or scarring persisted, it was less dense and lightened with the latter treatment, improving not only the ocular appearance but also the visual axis. B. Eyelid. Membrane adhered to the cornea. C. Partial corneal remodeling: the lesion still has a superficial ulcer and deep corneal vascularization. D. More uniform corneal remodeling with simple walleye and phantom vessels. E. Adequate corneal remodeling and simple leucoma without affecting the visual axis Discussion and conclusions This report aims to emphasize the positive impact of type I bovine skin-derived collagen membranes for veterinary use on regeneration and corneal transparency in 12 brachycephalic and, consequently, exophthalmic dog patients with deep and perforating corneal ulcers. Satisfactory results were achieved at the 60-day postsurgery evaluation and subsequent follow-ups within 3 months. To address desiccation concerns related to type I bovine skin-derived collagen membranes, a 360-degree conjunctival flap was implemented along with temporary tarsorrhaphy as an adjunctive technique. This approach was particularly beneficial for brachycephalic patients with marked eyeball exposure, tear evaporation syndrome, and difficulties in management due to anxiety or nervousness (patients 1, 3, and 4). This is because the conjunctival flap acts as a biological shield that protects the membrane placed over the cornea. This is essential to prevent graft displacement, desiccation, or loss and to ensure its integration with the corneal tissue. Although the literature reports that performing both procedures are not necessary to correct the defect, the authors' experience suggests that when a 360° conjunctival flap is applied, the degradation process of the membrane is slower, there is less desiccation, and the re-epithelialization process is more complete than in cases where the flap is not used. In addition, considering the owners' nervousness and aversion to seeing exposed conjunctival tissue, tarsorrhaphy was performed, leaving space in the tear area for the application of drops. The membranes used in this study were composed of type I bovine skin-derived collagen fibers that were purified and processed for safe use. These membranes possess two surfaces, one rough and irregular and the other flat, that can be used interchangeably based on the specific pathology. The choice between the surfaces depends on the nature of the condition being treated. The rough side is recommended for corneal defects in cases where a more resistant tectonic floor is desired to ensure no leakage of aqueous humor, especially in cases of perforation. A smooth or flat surface is suggested for descemetocele or deep stromal defects. Importantly, both sides are composed of the same type I collagen material. While most corneal epithelial defects typically heal without complications through an integrated process of wound healing, the resolution of epithelial injuries in the eye can be influenced by various factors. Lagophthalmos or nerve damage, inflammation, or infection of the cornea may contribute to persistent epithelial defects, stromal thinning, and endothelial damage. These factors can impede the normal healing process, potentially leading to more significant issues and complications in the cornea (Lee and Tseng 1997 ; Jain and Rastogi 2004 ). The conventional treatment for corneal epithelial defects focuses on addressing the underlying disease mechanism, controlling inflammation, and protecting the ocular surface. However, a percentage of epithelial defects, especially deep ulcers or descemetoceles, may not respond adequately to standard treatment. Moreover, more complicated cases can lead to corneal perforation. These situations are considered emergencies owing to the potential for catastrophic consequences, including the loss of the eye or, in rare cases, ascending infection into the optic nerve leading to meningitis. Swift and effective interventions are crucial for preventing severe complications in such cases (Meneses and Serna 2000 ; Peña and Leiva 2012 ; Gelatt et al. 2022b ). Corneal ulcerative lesions are common in canine clinical practice, and biological membrane implants have proven to be valuable tools for enhancing animal health. These implants yield positive and rapid results while minimizing corneal fibrosis. Various tissues obtained from animals, preserved through different techniques, and implanted in recipients of the same or a different species facilitate the repair of wounds characterized by extensive tissue loss or an inability to induce healing by primary intention (Lee and Tseng 1997 ; Shin et al. 2003 ; Jain and Rastogi 2004 ; Trujillo-Piso et al. 2016 ). Despite the notable advantages of biological membranes, their utilization in clinical and surgical routines is not widespread, which is primarily attributed to a lack of understanding of their characteristics, handling, and implantation in veterinary medicine. In the field of ophthalmology, the use of fetal membranes in clinical practice dates to De Rotth in 1940 and Sorsby in 1947, who pioneered their application in the reconstruction of the conjunctival surface (Fontenla et al. 2003 ). In the context of corneal reconstruction, the amniotic membrane was initially employed in experimental settings and later applied therapeutically in various conditions, such as burns, ulcers, perforations, keratomalacia, keratoconus, and other related cases. The experimental use paved the way for its clinical application, demonstrating its efficacy in addressing a range of corneal issues. The amniotic membrane has proven to be a versatile and beneficial tool for promoting the healing and regeneration of the cornea under diverse pathological conditions (Chiaradía et al. 2010 ). Currently, these types of biological membranes have applications in various ocular surface diseases, serving as therapeutic options for conditions such as neurotrophic keratitis and persistent epithelial defects (Shin et al. 2003 ), band keratopathy (Andresen et al. 2002 ), bullous keratopathy (Tang et al. 2003 ), keratoplasty for cornea and bulbar conjunctiva coverage (Choi et al. 1998 ), postconjunctival mass removal (Espana et al. 2002 ), reconstruction of the ocular surface in acute chemical injury-related symblepharon (Tamhane et al. 2005 ), chronic limbal deficiency, and preparation of the surface for future corneal transplantation. The versatility of biological membranes makes them a convenient therapeutic alternative, particularly when conventional medical treatments prove ineffective in addressing corneal lesions. In the field of veterinary medicine, various types of biological membranes have been utilized as implants to facilitate tissue repair. These include the fascia lata (from different species), equine amniotic membrane, bovine pericardium, auricular cartilage, equine pericardium, bovine peritoneum, bovine nuchal ligament, porcine intestinal submucosa, porcine tendons, acellular dermal matrix, jugular vein, calcaneal tendon, canine small intestine submucosa, and human umbilical cord, among others. These biological membranes have demonstrated positive outcomes in supporting tissue repair in veterinary patients (Chow and Westermeyer 2015 ; Trujillo-Piso et al. 2016 ; Cognard et al. 2022 ). In the case of type I bovine skin-derived collagen membranes, the collagen fibers within the membrane provide organic proteins, which are considered crucial structural components in an organism. Collagen imparts tensile strength to tissues and forms highly resistant, flexible fibers. Moreover, the use of this membrane promotes the presence and activity of growth factors such as basic fibroblast growth factor, hepatocyte growth factor, and transforming growth factor-β17. In addition, these membranes contribute to the production of various antiangiogenic and anti-inflammatory proteins, along with serving as natural inhibitors of various proteases. These unique properties make these biological membranes favorable for tissue epithelialization, reduce inflammation, act as suitable substrates for scarring, and alleviate pain (Chiaradía et al. 2010 ). Another advantage of using collagen membranes lies in the approach to patients presenting with deep and perforating ulcers during emergency consultations. The focus in these cases should be not only on healing the lesion but also on minimizing its visibility. In such scenarios, collagen membranes offer advantages over other options because their collagen fibers create an optimal environment for cell adhesion, growth, and differentiation. This promotes effective tissue repair and regeneration while contributing to a more inconspicuous scarring process, which is particularly beneficial in the context of corneal injuries (Gelatt et al. 2022b ). In the present report, type I bovine skin-derived collagen membranes were employed as a tectonic floor to cover the corneal defect, leading to an improvement in the epithelialization process. The use of these membranes contributed to the structural support needed for effective healing and regeneration of the cornea, enhancing the overall epithelialization of the affected area. This approach demonstrates the utility of these collagen membranes in promoting optimal tissue repair in cases of corneal defects. We acknowledge the importance of comparative studies to validate treatment efficacy and recognize the lack of a control group as a limitation of this report. However, we emphasize that our purpose is not to establish comparative efficacy but to document clinical outcomes in patients treated with bovine collagen membranes. In patients with a positive Seidel test and subsequent hypotony of the eyeball, the placement of the membrane presented additional challenges. The stroma tended to fold during suture passage, even with prior chamber preparation (e.g., intracameral application of balanced saline solution or 2% sodium hyaluronate). Addressing these cases requires the addition of extra sutures to ensure precise membrane fixation. The surgical procedure duration was extended by 1,520 minutes in such patients, and the use of a balanced saline solution and an air bubble was necessary to correct staphyloma. Notably, scarring and corneal vascularization were more pronounced in these patients, with some developing anterior synechiae associated with the degree of ocular perforation. Managing membrane placement in cases with a positive Seidel test and a hypotonic eyeball demands extra attention and specific measures to navigate the challenges posed by the ocular conditions. According to the authors' experience, in cases where a large staphyloma with significant corneal thinning is present, injecting the viscoelastic agent directly through the perforated area carries a greater risk of increased hemorrhage and further lesion expansion. Additionally, this approach may not allow for adequate anterior chamber reformation. Performing controlled paracentesis helps minimize these risks, ensuring more stable and effective chamber reformation while reducing surgical complications. While corneal injury classification scales exist, it is important to highlight that, based on our review prior to conducting this study, none of them fully align with the key criteria considered relevant according to the authors’ clinical experience. This is particularly due to the unique characteristics of brachycephalic canine patients, whose anatomical exophthalmia and specific ocular predispositions require tailored evaluation parameters. Heterologous serum contains components similar to those of natural tears, making it highly beneficial for corneal regeneration. Growth factors such as EGF, TGF-β, and FGF promote cell proliferation and epithelial healing while helping restore the epithelial barrier damaged by the ulcer. Vitronectin and fibronectin facilitate cell adhesion and migration, which are essential for corneal epithelial repair. Lysozyme, lactoferrin, and immunoglobulins provide antimicrobial and anti-inflammatory properties, reducing the risk of secondary infections. Additionally, albumin and vitamins A, C, and E help maintain corneal hydration and decrease inflammation (Lekhanont et al. 2016 ). In summary, based on our results, the utilization of 200 µm type I bovine skin-derived collagen membranes, in conjunction with a 360-degree conjunctival flap and temporary tarsorrhaphy, proves to be an excellent adjuvant in the healing process of deep and perforating corneal lesions in dogs. These membranes serve as a tectonic floor to fill defects, promoting comprehensive corneal remodeling and reducing adverse scarring that might otherwise impact the visual axis. The combination of these techniques is effective in achieving positive outcomes in the treatment of corneal injuries in canine patients. Declarations Author contributions S.P.A. conceptualized the study, developed the methodology, conducted the investigation, drafted the original manuscript, and created the visualizations. N.M.C.V. contributed to the methodology, performed the formal analysis, participated in drafting the original manuscript, and assisted in preparing the visualizations. All authors have read and approved the final version of the manuscript. Funding No funding was received for this study. Data availability No datasets were generated or analyzed during the current study. Ethical approval This study adheres to the Guidelines for Ethical Research in Veterinary Ophthalmology (GERVO) and is exempt from formal ethics committee approval. All procedures were part of standard clinical care routinely provided by licensed veterinary ophthalmologists, with no experimental interventions beyond those accepted in clinical practice. Treatments were conducted as medically necessary interventions for animals presenting with advanced ocular pathology. Informed written consent was obtained from all pet owners, explicitly authorizing both the therapeutic procedures and the use of anonymized clinical data for scientific dissemination. The exemption from formal ethical review is in accordance with local regulations and GERVO criteria, and this has been more clearly articulated in the revised manuscript. Competing interests Both authors declare no compet­ing interests. References Andresen JL, Ledet T, Hager H, Josephsen K, Ehlers N (2002) The influence of corneal stromal matrix proteins on the migration of human corneal fibroblasts. Exp Eye Res 71(1):33–43. https://doi.org/10.1006/exer.2000.0850 Chiaradía P, Tytiun A, Botta MJ, Albornoz S, Huarte L, Abuin L (2010) Uso de membrana amniótica en reconstrucción de superficie ocular: resultados preliminares. Oftalmol Clin Exp 4(2):64–68 https://oftalmologos.org.ar/oce_anteriores/files/original/502c7e2bc34f6025af9d37357958da83.pdf Choi YS, Kim JY, Wee WR, Lee JH (1998) Effect of application of human amniotic membrane on rabbit corneal wound healing after excimer laser photorefractive keratectomy. Cornea 17:389–395. https://doi.org/10.1097/00003226-199807000-00009 Chow DWY, Westermeyer HD (2015) Retrospective evaluation of corneal reconstruction using ACell VetTM alone in dogs and cats: 82 cases. Vet Ophthalmol:1–10. https://doi.org/10.1111/vop.12294 Cognard S, Barnouin L, Bosc J, Gindraux F, Robin MC, Douet JY, Thuret G (2022) New devitalized freeze-dried human umbilical cord amniotic membrane as an innovative treatment of ocular surface defects: preclinical results. J Funct Biomater 13(3):150. https://doi.org/10.3390/jfb13030150 Espana EM, Prabhasawat P, Grueterich M, Solomon A, Tseng SC (2002) Amniotic membrane transplantation for reconstruction after excision of large ocular surface neoplasias. Br J Ophthalmol 86:640–645. https://doi.org/10.1136/bjo.86.6.640 Fontenla JR, Vázquez X, Díaz P, Gatell J, Pita D (2003) Membrana amniótica. Características, efectos y aplicaciones en oftalmología. CTS 64:587–601 Gelatt KN, Gelatt JP, Plummer C (2022a) Surgical procedures for the conjunctiva and the nictitating membrane. In: Veterinary Ophthalmic Surgery. Second edition (Ed. Elsevier) Gelatt KN, Gelatt JP, Plummer C (2022b) Surgery of the cornea and sclera. In: Veterinary Ophthalmic Surgery. Second edition (Ed. Elsevier) Herrera D. Enfermedades de la córnea (2007) In: Daniel H. Oftalmología clínica en animales. Schering-plough.1st ed. Buenos Aires: Inter-Médica, pp 113–144 Jain S, Rastogi A. Evaluation of the outcome of amniotic membrane transplantation for ocular surface reconstruction in symblepharon. Eye 2004;18:1251–1257. https://doi.org/10.1038/sj.eye.6701379 Lee S-H, Tseng SCG (1997) Amniotic membrane transplantation for persistent epithelial defects with ulceration. Am J Ophthalmol 123:303–312. https://doi.org/10.1016/S0002-9394(14)70125-4 Lekhanont K, Jongkhajornpong P, Anothaisintawee T, Chuckpaiwong V (2016) Undiluted serum eye drops for the treatment of persistent corneal epitheilal defects. Sci Rep.6:38143. https://doi.org/10.1038/srep38143 Meneses C, Serna M (2000) Surgical techniques for the repair of deep ulcers of the cornea. Rev Vet Perú 1(2):157–162. Peña MT, Leiva M (2012) Claves clínicas para el diagnóstico y tratamiento de las úlceras corneales en el perro. Clin Vet Peq Anim 32:15–26. https://ddd.uab.cat/pub/clivetpeqani/clivetpeqani_a2012v32n1/clivetpeqaniv32n1p15.pdf Shin KS, Chung IY, Seo SW (2003) The effect of amniotic membrane transplantation for corneal ulcer and ocular surface diseases. J Korean Ophthalmol Soc 44:1305–1310. Tamhane A, Vajpayee RB, Biswas NR, Pandey RM, Sharma N, Titiyal JS, Tandon R (2005) Evaluation of amniotic membrane transplantation as an adjunct to medical therapy as compared with medical therapy alone in acute ocular burns. Ophthalmology 112:1963–1969. https://doi.org/10.1016/j.ophtha.2005.05.022 Tang GG, Ahn HB, Park WC (2003) The clinical effects of dye-amniotic membrane transplantation on bullous keratopathy. J Korean Ophthalmol Soc 44:1741–1747. Trujillo-Piso DY, Zamora-Restán WA, Padilla-Barreto MY (2016). Implantes de membranas biológicas en cirugía reconstructiva veterinaria: Aspectos básicos y métodos de conservación. Rev Med Vet 31:105–120. http://www.scielo.org.co/pdf/rmv/n31/n31a11.pdf Whitley RD (2000) Canine and feline primary ocular bacterial infections. Vet Clin North Am Small Anim 30:1151–1167. https://doi.org/10.1016/S0195-5616(00)05012-9 Wiemer P, Gruys E, van Hoeck B (2005) Study of seven different types of grafts for jugular vein transplantation in the horse. Res Vet Sci 79(3):211–217. https://doi.org/10.1016/j.rvsc.2004.12.005 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 30 Jul, 2025 Read the published version in Veterinary Research Communications → Version 1 posted Editorial decision: Revision requested 01 Jun, 2025 Reviews received at journal 29 May, 2025 Reviewers agreed at journal 27 May, 2025 Reviewers invited by journal 27 May, 2025 Editor assigned by journal 26 May, 2025 Submission checks completed at journal 26 May, 2025 First submitted to journal 23 May, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6733977","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":463224407,"identity":"8171def9-44f3-4453-a12a-e7c0d3762e2c","order_by":0,"name":"Sandra P. Acevedo","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABFElEQVRIie2QMUsDMRTH49IsD26THDnqV3hS0B4c9KucFDJF7CRuunUw7kK/RN0dcgTsco7CHbfYpS4dnKTCDU1O3O5q3UTyGx4v4f34v4QQj+dvcqC/O0YmQyD0xrY43Ok0CjQKMiDgzsj2V2xNvxK7CGiO+vPR9EeHJivekUWn4dvLfDNhJJjepm1KqCRmamUGwMU4vreLxTN5WSobx/LneZuCBaAGLc4UlyccrIKVFPbSLXneqWS1FteKX3zw2illLsr6B8WATlLgssfdj2FBn6pdKaESExPp5FhVYhArp+SyV0W26XpLQM3Dcq3ZEZ2Nl8XmKhnhYrEq13XSD6Z3rUobgE3dd9xBX38z7fF4PP+fLYM9Xuc4Plp9AAAAAElFTkSuQmCC","orcid":"","institution":"","correspondingAuthor":true,"prefix":"","firstName":"Sandra","middleName":"P.","lastName":"Acevedo","suffix":""},{"id":463224409,"identity":"60167021-0343-4993-8aca-1fc601d50ed6","order_by":1,"name":"Nathalia M. Correa-Valencia","email":"","orcid":"","institution":"University of Antioquia","correspondingAuthor":false,"prefix":"","firstName":"Nathalia","middleName":"M.","lastName":"Correa-Valencia","suffix":""}],"badges":[],"createdAt":"2025-05-23 14:53:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6733977/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6733977/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11259-025-10829-2","type":"published","date":"2025-07-30T16:13:28+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":83681582,"identity":"e37935ba-5ae8-447c-b20d-0d53e3defc77","added_by":"auto","created_at":"2025-05-30 16:18:03","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":171629,"visible":true,"origin":"","legend":"\u003cp\u003eThe photographic evolution of each ophthalmological evaluation of Patient 2 was as follows: A. Deep ulcer and descematocele with generalized corneal edema and onset of leakage.\u003c/p\u003e\n\u003cp\u003eB. Membrane adhered to the cornea. C. Adequate corneal healing with 90% moderate granulation tissue, without iridal exposure. D. Moderate leucoma and phantom vessels, with adequate corneal remodeling. E. Simple leucoma, ensuring an adequate visual axis\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6733977/v1/888634242f60b5bb86ff226a.jpg"},{"id":83681583,"identity":"04163d3a-11a5-406c-9bda-088ee5de48e4","added_by":"auto","created_at":"2025-05-30 16:18:03","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":192003,"visible":true,"origin":"","legend":"\u003cp\u003eThe comparative photographic evolution of each ophthalmological evaluation of Patient 4 was as follows: A. The ulcer was perforated, with a positive Seidel test and active microleakage.\u003c/p\u003e\n\u003cp\u003eB. Eyelid. Membrane adhered to the cornea. C. Partial corneal remodeling: the lesion still has a superficial ulcer and deep corneal vascularization. D. More uniform corneal remodeling with simple walleye and phantom vessels. E. Adequate corneal remodeling and simple leucoma without affecting the visual axis\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6733977/v1/8a62bf7500663e8bd36bc9d8.jpg"},{"id":88268303,"identity":"b7d772f2-89bb-4116-a882-b5c4b49ac4cd","added_by":"auto","created_at":"2025-08-04 16:50:51","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":946193,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6733977/v1/d57bf1c2-b4fd-427a-a497-015fc8fc3e60.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Use of type I bovine collagen membranes for treating deep and perforating corneal ulcers in brachycephalic dogs","fulltext":[{"header":"Background","content":"\u003cp\u003eCorneal ulcers represent one of the most prevalent reasons for ophthalmological consultations in routine veterinary clinics for both dogs and cats. Characterized by a disruption in the integrity of the corneal epithelial layer, these ulcers initially present as corneal erosion, involving superficial epithelial disruption without stromal damage. If complications ensue, the ulceration may advance to a descemetocele, reaching through the cornea and stroma to the levels of Descemet's membrane. In more severe instances, complete perforation, extending across all layers of the cornea, can occur (Gelatt et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2022a\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003eb\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eSuch outcomes can lead to visual impairments and, in more critical scenarios, may be complicated by intraocular infection, ultimately resulting in total loss of ocular structure. This progression is attributed to the release of proteolytic enzymes and toxins. Therefore, early diagnosis and effective treatment are imperative to prevent complications such as corneal perforation and alterations in transparency (Whitley \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2000\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eWhile most corneal defects resolve without complications, epithelial wound healing can be impeded by various pathological factors, leading to persistent epithelial defects and stromal thinning. The traditional treatment for such defects centers on addressing the underlying disease mechanism, controlling inflammation, and safeguarding the corneal surface. Nevertheless, many corneal defects, especially those that are deep and stromal, do not respond to this therapeutic approach. This lack of responsiveness can escalate to imminent perforation, primarily due to bacterial contamination and ocular trauma (Herrera \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2007\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe response to treatment may prompt the consideration of surgical options to address the resulting defect. Conjunctival plasty techniques have emerged as valuable tools in the regeneration of deep and perforating corneal injuries, offering significant healing effects through tissue fixation. However, it is important to note that such techniques can also be associated with the formation of granulation tissue, potentially impacting the surgical result (Meneses and Serna \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2000\u003c/span\u003e; Pe\u0026ntilde;a and Leiva \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). This effect is attributed mainly to local alterations that can occur during the healing process.\u003c/p\u003e \u003cp\u003eTraditional surgical techniques for managing deep corneal and descemetocele ulcers include the third eyelid flap, 180\u0026deg; flap, 360\u0026deg; flap, and pedicle flap. These procedures involve the utilization of supporting tissue from the conjunctiva to facilitate epithelial regeneration and repair. In addition, the use of biologic membrane implants derived from allogeneic or xenogeneic sources represents a significant alternative for treating corneal ulcerative and perforating lesions. These implants aim not only to address the primary lesion but also to promote the formation of innocuous scar tissue that minimally impacts corneal transparency and, consequently, visual capacity (Wiemer et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2005\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eConsidering the evolving landscape of veterinary ophthalmology in recent decades, understanding corneal ulcers and their treatment has become essential. Consequently, this report aims to assess the effectiveness of 200 \u0026micro;m type I bovine skin-derived collagen membranes in the treatment of deep and penetrating corneal ulcers in dogs.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eThis report presents a descriptive study comprising 12 cases in dogs treated at the Ocularvet Ophthalmological Unit in the city of Medellín (Antioquia, Colombia). The study population consisted of 12 patients characterized by breed, sex, and age. Among them were a French bulldog male, 8 years old (patient 1); an American bulldog male, 6 years old (patient 2); a French bulldog female, 2 years old (patient 3); and another French bulldog female, 4 years old (patient 4). The group also included a crossbred (American Bulldog × Bully) male, 5 years old (patient 5); a Boston Terrier female, 3 years old (patient 6); a Shih Tzu male, 2 years old (patient 7); and another Shih Tzu male, 3 years old (patient 8). Additionally, there was a Bulldog male, 2 years old (patient 9); a Shih Tzu female, 2 years old (patient 10); another Shih Tzu female, 4 years old (patient 11); and finally, a Shih Tzu male, 8 years old (patient 12). These patients were diagnosed with descemetocele (deep ulcer) and/or ocular perforation, indicating advanced damage to the corneal stroma that was refractory to intensive medical therapy, resulting in compromised eye integrity.\u003c/p\u003e \u003cp\u003eThe V-injury score scale, as outlined in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, was applied both before and after surgery under the guidance of the treating veterinary ophthalmologist. A comprehensive ophthalmological evaluation was conducted utilizing a portable slit lamp (Kowa SL-19®, Kowa Co., Ltd., Tokyo, Japan) to ascertain the depth of the lesion. Fluorescein and, when necessary, Seidel tests were performed. Lesion size and associated signs, such as corneal edema and ciliary vascularization, were measured millimetrically via a direct ophthalmoscope (Welch Allyn 11720®, Welch Allyn Co., USA). IOP was measured via applanation tonometry with a Tono-pen Vet™ device (Reichert Metek. NY, USA) via applanation-based technology, which employs micro strain gauge technology and a 1.0 mm-diameter transducer tip.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe V-injury score scale used both before and after surgery\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDescription\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eThe prognosis is very good, as the lesion is solely located in the cornea with no synechia. There is no presence of neovascularization or corneal edema\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eThe prognosis is good, with no synechia observed. However, there is moderate corneal edema, accompanied by the superficial presence of vessels\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eReserved prognosis with moderate synechia with brush vascularization, and corneal edema exceeding 50%\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIV\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eReserved prognosis due to marked synechia, generalized neovascularization, and significant corneal edema\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eV\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePoor prognosis with complete conjunctival and limbal involvement, generalized neovascularization, dense scleral vessel infiltration, hypotonic eye, and potential epithelial, stromal, and Descemet's membrane involvement\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eClinical findings revealed that patients experienced marked ocular pain related to corneal injury, ocular hypotonia due to secondary uveitis, and, in some cases, diffuse corneal edema and corneal vascularization. Examination of the ocular fundus via both direct (optical diopters of 0 and − 1) (Welch Allyn 11720®, Welch Allyn Co., USA) and indirect (optical diopter of 22) (Keeler Vantage®, Keeler Vantage Co., USA) ophthalmoscopies were challenging because of corneal opacity and inflammation in the anterior uvea, resulting in a positive Tyndall effect for uveitis response. Patients exhibit symptoms such as loss of appetite, behavioral changes (e.g., aggression, apathy), sudden rubbing of the affected eye, and, in some cases, mucoid secretion. Additionally, visual deficits associated with corneal lesions or opacities, along with possible miosis due to uveitis, were noted.\u003c/p\u003e \u003cp\u003eThis pathology is considered an emergency, requiring surgical intervention within the next 12 hours. For the insertion of the 360-degree conjunctival flap, neuroleptanalgesia was administered to all patients via tramadol (Tramal®, Laboratorios Genfar, Bogotá, Colombia) at a rate of 3 mg/kg BW and acepromazine (Acedan®, Laboratorio Holliday, Buenos Aires, Argentina) at 0.3 mg/kg BW, IM.\u003c/p\u003e \u003cp\u003eThe surgical procedure was conducted under general anesthesia, with 1% propofol induction (Propofol al 1%®, Braun, Bogotá, Colombia) at 5 mg/kg BW, IV, and maintenance with isoflurane (Isoflorano®, Laboratorio Baxter, Cali, Colombia) at 5 mg/kg BW. A muscle relaxant was administered during the procedure to facilitate centering of the eyeball (rocuronium; Rocuronio bromuro®, Vitalis, Quito, Ecuador, at 0.02 mg/kg BW, administered slowly IV). All surgeries were performed by the same surgeon.\u003c/p\u003e \u003cp\u003eEach of the 12 canine patients underwent surgical insertion of a 200 µm type I bovine skin-derived collagen membrane, exclusively for veterinary use (Collagen Membrane®, AJL Ophthalmic S.A., Álava, Spain), into the corneal lesion via surgical nylon (Ethylon 9 − 0®, Ethalloy, Bogotá, Colombia) with simple stitches (between 14 and 16). The surface was protected with a 360-degree conjunctival flap using polydactin (Vicryl 5 − 0®, Ethalloy, Bogotá, Colombia) with U stitches (four) and temporary tarsorrhaphy using surgical nylon (Corpalon 4 − 0®, Master Medical, Bogotá, Colombia) with U points (two). The conjunctival flap and temporary tarsorrhaphy were employed to safeguard the membrane, preventing the loss of tension or denaturation before the healing period.\u003c/p\u003e \u003cp\u003eBriefly, the membrane was hydrated for 20 minutes in a balanced salt solution under aseptic conditions. The initial disinfection of the affected eye involved the corneal and periocular application of 1% povidone-iodine. In cases with limbal perforation, paracentesis was performed via a 12–15-degree ophthalmic knife at the 12:00–14:00 circle position (depending on the lesion). A 2% hyaluronate cohesive viscoelastic mixture was applied to reinforce the chamber, especially in patients with atlamydia. For cases with perforation and staphyloma, the same procedure was performed, along with iris repositioning (i.e., moving the iris to its correct position) in specific cases (Patients 1, 6, 10, 11, and 12). If an exposed staphyloma was identified (5 out of 12 patients) a protrusion or bulging of weakened ocular tissue, typically the uveal tissue (choroid and retina) or sclera, that becomes externally visible owing to thinning or loss of the overlying structures, such as the conjunctiva or cornea. This defect was removed, and the chamber was repaired before membrane placement. In addition, a single dose of cefovecin sodium (Convenia®, Zoetis, Parsippany, NJ, USA) was administered intraoperatively at 8 mg/kg BW, SC.\u003c/p\u003e \u003cp\u003eIn each case, the membrane was positioned on the corneal defect, ensuring that the smooth face of the graft aligned with the affected cornea. Subsequently, through the same limbal paracentesis, a balanced saline solution was infused via a Simcoe cannula, the viscoelastic device was aspirated, and the solution was left in the anterior chamber. The graft was then hydrated with drops of balanced saline solution, and accommodation was performed via an iris spatula. Simple stitches were used for attachment, employing nonabsorbable material (Ethylon 9 − 0®, Ethalloy, Bogotá, Colombia) in two patients (1 and 4) and polyglycolic acid (8 − 0) in the others, owing to material availability issues. Sutures were placed around the graft and secured to the healthy cornea (2–3 mm from the defect), ensuring attachment and confirming the absence of aqueous humor leakage in cases of perforation. This procedure effectively covered the entire corneal defect.\u003c/p\u003e \u003cp\u003eAfter surgery, the postoperative treatment for all patients included the use of an Elizabeth collar, along with ciprofloxacin plus chondroitin sulfate eye drops (Ciprovet®, Labyes, Morón, Argentina). One eye drop was administered to the operated eye every 8 hours for the initial 15 days, followed by every 12 hours for the subsequent 15 days, and finally, every 24 hours for the remaining 15 days, completing a 45-day treatment. In addition, sodium hyaluronate plus chondroitin sulfate eye drops (Humylub Ofteno Pf®, Laboratorios Sophia de Colombia Ltda.) were applied every 8 hours to the operated eye for a duration of 2 months. Oral meloxicam drops (Meloxic®, Laboratorios Provet, Bogotá, Colombia) at a rate of 0.1 mg/kg BW were administered every 24 hours for 3 days. The eye drops were applied on the 360-degree conjunctival flap through the narrow temporal tarsorrhaphy opening for the initial 15 days. From day 16 to day 60, eye drops were applied to the cornea through normal eyelid opening.\u003c/p\u003e \u003cp\u003eEach patient underwent evaluations on day 15, involving the removal of the tarsorrhaphy and conjunctival plasty sutures. Subsequent evaluations were conducted on days 30 and 60 after surgery, and the presence/absence of an active corneal ulcer was assessed via a fluorescein test. Measurements of the size of the corneal opacity (in mm), presence/absence of superficial and deep vessels, presence/absence of granulation tissue, threat response, and ocular fundus evaluation were performed through a complete ophthalmological examination (when possible, given the conditions in which the patients arrived). The IOP was assessed as previously described.\u003c/p\u003e \u003cp\u003eFor the removal of the 360-degree conjunctival flap, neuroleptanalgesia was administered to all patients as described previously. In addition, a topical proximetacaine (Alcaine®, Laboratorios Alcon. Bogotá, Colombia) was applied, and the sutures were removed with a magnifying glass, and the dose of proparacaine was repeated if necessary.\u003c/p\u003e \u003cp\u003eSuccessful results to treatment were defined as those eyes with stable IOPs between 15 and 25 mmHg whose corneal lesions presented total re-epithelialization (negative fluorescein test and Seidel test) at the time of evaluation. In addition, the recovery of corneal transparency was evaluated at each moment, defined according to the decrease in corneal edema and the presence/absence of corneal superficial and deep vessels, as well as the size of the corneal scar (leucoma) and ocular fundus examination. An injury description was defined both before and after surgery (Shin et al. 2033). Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e illustrates the progression of patients based on the V-injury score scale and the follow-up of IOP. Clinical examinations and IOP measurements were conducted for each patient on days 15, 30, and 60 after surgery.\u003c/p\u003e \u003cp\u003eIn the initial measurements during surgery, all patients presented decreased IOP associated with ocular perforation. Aqueous humor loss was observed in four patients (4, 6, 9, and 10), whereas the other two patients (7 and 8) with deep ulcers had active uveitis. On day 15 after surgery, upon suture removal, notable improvement was observed, with stable IOPs and no signs of pain on palpation. Episcleritis and moderate conjunctival inflammation persisted in all patients due to the corneal regeneration process and 360-degree conjunctival flap removal. The injury score at this point was II in 10 patients (2, 3, 4, 5, 6, 7, 9, 10, 11, and 12), indicating a good prognosis with no limbal involvement, superficial vessels, and moderate edema.\u003c/p\u003e \u003cp\u003eOne patient still had more than 50% corneal edema and limbal involvement, although in the process of corneal remodeling. Notably, this patient arrived at the clinic with severe corneal perforation already affecting the visual axis at the time of surgery.\u003c/p\u003e \u003cp\u003eThirty days after surgery, all patients remodeled the corneal defect with stable IOPs, and there were no active ulcers. Two patients (1 and 4), who initially presented with perforation, still had moderate edema and superficial vascularization. By day 60, all patients maintained stable IOPs. Four patients (2, 4, 7, and 8) presented simple leucoma without visual axis involvement or active corneal alteration. Only one patient, who initially experienced perforation, still exhibited moderate edema and superficial vessels but without an active lesion. Adequate corneal re-epithelialization was confirmed in all patients, with varying degrees of scarring. A threat response was observed in all patients at the time of evaluation, and total or partial exploration of the ocular fundus was conducted since the density of the leucoma.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCharacterization of the affected eyes at the time of surgery and follow-up on days 15, 30, and 60 after surgery\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"10\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePatient\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLesion at the time of surgery\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eIOP at the time of surgery (in mmHg)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eInjury score at the time of surgery\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eIOP − 15 days of evolution (in mmHg)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eInjury score − 15 days of evolution\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eIOP − 30 days of evolution (in mmHg)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eInjury score − 30 days of evolution\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eIOP − 60 days of evolution (in mmHg)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eInjury score − 60 days of evolution\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePerforating\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eV\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eIII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eProfound\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eIII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eLeukoma\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eProfound\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eIII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePerforating\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eIV\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eLeukoma\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eProfound\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eIV\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePerforating\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eV\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNot determined\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNot determined\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eProfound\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eIII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eLeukoma\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eProfound\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eV\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eIII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eLeukoma\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePerforating\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eIV\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePerforating\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eIV\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePerforating\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eIV\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePerforating\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eIV\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eIOP: Intraocular pressure. *According to a self-designed V- injury score scale.\u003c/p\u003e \u003cp\u003ePhotographic evidence of two patients' processes is presented (2 and 4), showing the conditions before (A) and after membrane application (B), as well as evaluations at different postsurgery time points (C, D, and E for 15, 30, and 60 days, respectively, and when applied). Figure\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e illustrates the specific evolution of patient 2, who faced a challenging prognosis with ocular perforation, severe corneal edema, and intracameral inflammation. The sequence of images provides a comprehensive visual representation of the patient's progress, revealing the stages from the initial condition to the eventual improvement with the applied treatment. Satisfactory results were achieved, showing extensive corneal regeneration and simple leucoma for such deep lesions, leading to visual recovery. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the specific evolution of patient 4, which was characterized by notable and remarkable corneal regeneration. A simple leucoma developed without affecting the visual axis, despite the initial presentation of a deep ulcer with significant corneal inflammation and generalized edema. The images illustrate the step-by-step progress of Patient 4, capturing key moments from the initial condition to the final stage of the healing process. Regrettably, patient 6 passed away before the 60-day postsurgery review, which was attributed to nonocularly related causes. The photographic follow-up data for all 12 patients are available at \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://postimg.cc/gallery/YjWyDGm\u003c/span\u003e\u003cspan address=\"https://postimg.cc/gallery/YjWyDGm\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eB. Membrane adhered to the cornea. C. Adequate corneal healing with 90% moderate granulation tissue, without iridal exposure. D. Moderate leucoma and phantom vessels, with adequate corneal remodeling. E. Simple leucoma, ensuring an adequate visual axis\u003c/p\u003e \u003cp\u003ePatients with corneal injury scores of I or II at 60 days after surgery (patients 1, 3, 5, 6, 9, and 10) received a therapy regimen comprising 1% cyclosporine eye drops (a master formula, distributed by Oftasalud S.A.S., Bogotá, Colombia) every 12 hours for 30 days, along with heterologous serum every 8 hours for 15 days. Satisfactory results were achieved, with recovery of corneal transparency in all patients who received the latter treatment. For other patients, the use of cyclosporine was not considered, as posthealing opacity was minimal and did not affect the visual axis. Although the leucoma or scarring persisted, it was less dense and lightened with the latter treatment, improving not only the ocular appearance but also the visual axis.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eB. Eyelid. Membrane adhered to the cornea. C. Partial corneal remodeling: the lesion still has a superficial ulcer and deep corneal vascularization. D. More uniform corneal remodeling with simple walleye and phantom vessels. E. Adequate corneal remodeling and simple leucoma without affecting the visual axis\u003c/p\u003e "},{"header":"Discussion and conclusions","content":"\u003cp\u003eThis report aims to emphasize the positive impact of type I bovine skin-derived collagen membranes for veterinary use on regeneration and corneal transparency in 12 brachycephalic and, consequently, exophthalmic dog patients with deep and perforating corneal ulcers. Satisfactory results were achieved at the 60-day postsurgery evaluation and subsequent follow-ups within 3 months.\u003c/p\u003e\u003cp\u003eTo address desiccation concerns related to type I bovine skin-derived collagen membranes, a 360-degree conjunctival flap was implemented along with temporary tarsorrhaphy as an adjunctive technique. This approach was particularly beneficial for brachycephalic patients with marked eyeball exposure, tear evaporation syndrome, and difficulties in management due to anxiety or nervousness (patients 1, 3, and 4). This is because the conjunctival flap acts as a biological shield that protects the membrane placed over the cornea. This is essential to prevent graft displacement, desiccation, or loss and to ensure its integration with the corneal tissue. Although the literature reports that performing both procedures are not necessary to correct the defect, the authors' experience suggests that when a 360° conjunctival flap is applied, the degradation process of the membrane is slower, there is less desiccation, and the re-epithelialization process is more complete than in cases where the flap is not used. In addition, considering the owners' nervousness and aversion to seeing exposed conjunctival tissue, tarsorrhaphy was performed, leaving space in the tear area for the application of drops.\u003c/p\u003e\u003cp\u003eThe membranes used in this study were composed of type I bovine skin-derived collagen fibers that were purified and processed for safe use. These membranes possess two surfaces, one rough and irregular and the other flat, that can be used interchangeably based on the specific pathology. The choice between the surfaces depends on the nature of the condition being treated. The rough side is recommended for corneal defects in cases where a more resistant tectonic floor is desired to ensure no leakage of aqueous humor, especially in cases of perforation. A smooth or flat surface is suggested for descemetocele or deep stromal defects. Importantly, both sides are composed of the same type I collagen material.\u003c/p\u003e\u003cp\u003eWhile most corneal epithelial defects typically heal without complications through an integrated process of wound healing, the resolution of epithelial injuries in the eye can be influenced by various factors. Lagophthalmos or nerve damage, inflammation, or infection of the cornea may contribute to persistent epithelial defects, stromal thinning, and endothelial damage. These factors can impede the normal healing process, potentially leading to more significant issues and complications in the cornea (Lee and Tseng \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e1997\u003c/span\u003e; Jain and Rastogi \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2004\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe conventional treatment for corneal epithelial defects focuses on addressing the underlying disease mechanism, controlling inflammation, and protecting the ocular surface. However, a percentage of epithelial defects, especially deep ulcers or descemetoceles, may not respond adequately to standard treatment. Moreover, more complicated cases can lead to corneal perforation. These situations are considered emergencies owing to the potential for catastrophic consequences, including the loss of the eye or, in rare cases, ascending infection into the optic nerve leading to meningitis. Swift and effective interventions are crucial for preventing severe complications in such cases (Meneses and Serna \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2000\u003c/span\u003e; Peña and Leiva \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Gelatt et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2022b\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eCorneal ulcerative lesions are common in canine clinical practice, and biological membrane implants have proven to be valuable tools for enhancing animal health. These implants yield positive and rapid results while minimizing corneal fibrosis. Various tissues obtained from animals, preserved through different techniques, and implanted in recipients of the same or a different species facilitate the repair of wounds characterized by extensive tissue loss or an inability to induce healing by primary intention (Lee and Tseng \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e1997\u003c/span\u003e; Shin et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2003\u003c/span\u003e; Jain and Rastogi \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2004\u003c/span\u003e; Trujillo-Piso et al. \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Despite the notable advantages of biological membranes, their utilization in clinical and surgical routines is not widespread, which is primarily attributed to a lack of understanding of their characteristics, handling, and implantation in veterinary medicine. In the field of ophthalmology, the use of fetal membranes in clinical practice dates to De Rotth in 1940 and Sorsby in 1947, who pioneered their application in the reconstruction of the conjunctival surface (Fontenla et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). In the context of corneal reconstruction, the amniotic membrane was initially employed in experimental settings and later applied therapeutically in various conditions, such as burns, ulcers, perforations, keratomalacia, keratoconus, and other related cases. The experimental use paved the way for its clinical application, demonstrating its efficacy in addressing a range of corneal issues. The amniotic membrane has proven to be a versatile and beneficial tool for promoting the healing and regeneration of the cornea under diverse pathological conditions (Chiaradía et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2010\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eCurrently, these types of biological membranes have applications in various ocular surface diseases, serving as therapeutic options for conditions such as neurotrophic keratitis and persistent epithelial defects (Shin et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2003\u003c/span\u003e), band keratopathy (Andresen et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2002\u003c/span\u003e), bullous keratopathy (Tang et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2003\u003c/span\u003e), keratoplasty for cornea and bulbar conjunctiva coverage (Choi et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e1998\u003c/span\u003e), postconjunctival mass removal (Espana et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2002\u003c/span\u003e), reconstruction of the ocular surface in acute chemical injury-related symblepharon (Tamhane et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2005\u003c/span\u003e), chronic limbal deficiency, and preparation of the surface for future corneal transplantation. The versatility of biological membranes makes them a convenient therapeutic alternative, particularly when conventional medical treatments prove ineffective in addressing corneal lesions.\u003c/p\u003e\u003cp\u003eIn the field of veterinary medicine, various types of biological membranes have been utilized as implants to facilitate tissue repair. These include the \u003cem\u003efascia lata\u003c/em\u003e (from different species), equine amniotic membrane, bovine pericardium, auricular cartilage, equine pericardium, bovine peritoneum, bovine nuchal ligament, porcine intestinal submucosa, porcine tendons, acellular dermal matrix, jugular vein, calcaneal tendon, canine small intestine submucosa, and human umbilical cord, among others. These biological membranes have demonstrated positive outcomes in supporting tissue repair in veterinary patients (Chow and Westermeyer \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Trujillo-Piso et al. \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Cognard et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn the case of type I bovine skin-derived collagen membranes, the collagen fibers within the membrane provide organic proteins, which are considered crucial structural components in an organism. Collagen imparts tensile strength to tissues and forms highly resistant, flexible fibers. Moreover, the use of this membrane promotes the presence and activity of growth factors such as basic fibroblast growth factor, hepatocyte growth factor, and transforming growth factor-β17. In addition, these membranes contribute to the production of various antiangiogenic and anti-inflammatory proteins, along with serving as natural inhibitors of various proteases. These unique properties make these biological membranes favorable for tissue epithelialization, reduce inflammation, act as suitable substrates for scarring, and alleviate pain (Chiaradía et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2010\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eAnother advantage of using collagen membranes lies in the approach to patients presenting with deep and perforating ulcers during emergency consultations. The focus in these cases should be not only on healing the lesion but also on minimizing its visibility. In such scenarios, collagen membranes offer advantages over other options because their collagen fibers create an optimal environment for cell adhesion, growth, and differentiation. This promotes effective tissue repair and regeneration while contributing to a more inconspicuous scarring process, which is particularly beneficial in the context of corneal injuries (Gelatt et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2022b\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn the present report, type I bovine skin-derived collagen membranes were employed as a tectonic floor to cover the corneal defect, leading to an improvement in the epithelialization process. The use of these membranes contributed to the structural support needed for effective healing and regeneration of the cornea, enhancing the overall epithelialization of the affected area. This approach demonstrates the utility of these collagen membranes in promoting optimal tissue repair in cases of corneal defects. We acknowledge the importance of comparative studies to validate treatment efficacy and recognize the lack of a control group as a limitation of this report. However, we emphasize that our purpose is not to establish comparative efficacy but to document clinical outcomes in patients treated with bovine collagen membranes.\u003c/p\u003e\u003cp\u003eIn patients with a positive Seidel test and subsequent hypotony of the eyeball, the placement of the membrane presented additional challenges. The stroma tended to fold during suture passage, even with prior chamber preparation (e.g., intracameral application of balanced saline solution or 2% sodium hyaluronate). Addressing these cases requires the addition of extra sutures to ensure precise membrane fixation. The surgical procedure duration was extended by 1,520 minutes in such patients, and the use of a balanced saline solution and an air bubble was necessary to correct staphyloma. Notably, scarring and corneal vascularization were more pronounced in these patients, with some developing anterior synechiae associated with the degree of ocular perforation. Managing membrane placement in cases with a positive Seidel test and a hypotonic eyeball demands extra attention and specific measures to navigate the challenges posed by the ocular conditions.\u003c/p\u003e\u003cp\u003eAccording to the authors' experience, in cases where a large staphyloma with significant corneal thinning is present, injecting the viscoelastic agent directly through the perforated area carries a greater risk of increased hemorrhage and further lesion expansion. Additionally, this approach may not allow for adequate anterior chamber reformation. Performing controlled paracentesis helps minimize these risks, ensuring more stable and effective chamber reformation while reducing surgical complications.\u003c/p\u003e\u003cp\u003eWhile corneal injury classification scales exist, it is important to highlight that, based on our review prior to conducting this study, none of them fully align with the key criteria considered relevant according to the authors’ clinical experience. This is particularly due to the unique characteristics of brachycephalic canine patients, whose anatomical exophthalmia and specific ocular predispositions require tailored evaluation parameters.\u003c/p\u003e\u003cp\u003eHeterologous serum contains components similar to those of natural tears, making it highly beneficial for corneal regeneration. Growth factors such as EGF, TGF-β, and FGF promote cell proliferation and epithelial healing while helping restore the epithelial barrier damaged by the ulcer. Vitronectin and fibronectin facilitate cell adhesion and migration, which are essential for corneal epithelial repair. Lysozyme, lactoferrin, and immunoglobulins provide antimicrobial and anti-inflammatory properties, reducing the risk of secondary infections. Additionally, albumin and vitamins A, C, and E help maintain corneal hydration and decrease inflammation (Lekhanont et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2016\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn summary, based on our results, the utilization of 200 µm type I bovine skin-derived collagen membranes, in conjunction with a 360-degree conjunctival flap and temporary tarsorrhaphy, proves to be an excellent adjuvant in the healing process of deep and perforating corneal lesions in dogs. These membranes serve as a tectonic floor to fill defects, promoting comprehensive corneal remodeling and reducing adverse scarring that might otherwise impact the visual axis. The combination of these techniques is effective in achieving positive outcomes in the treatment of corneal injuries in canine patients.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003eS.P.A. conceptualized the study, developed the methodology, conducted the investigation, drafted the original manuscript, and created the visualizations. N.M.C.V. contributed to the methodology, performed the formal analysis, participated in drafting the original manuscript, and assisted in preparing the visualizations.\u003c/p\u003e\n\u003cp\u003eAll authors have read and approved the final version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003eNo funding was received for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003eNo datasets were generated or analyzed during the current study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval\u0026nbsp;\u003c/strong\u003eThis study adheres to the Guidelines for Ethical Research in Veterinary Ophthalmology (GERVO) and is exempt from formal ethics committee approval. All procedures were part of standard clinical care routinely provided by licensed veterinary ophthalmologists, with no experimental interventions beyond those accepted in clinical practice. Treatments were conducted as medically necessary interventions for animals presenting with advanced ocular pathology. Informed written consent was obtained from all pet owners, explicitly authorizing both the therapeutic procedures and the use of anonymized clinical data for scientific dissemination. The exemption from formal ethical review is in accordance with local regulations and GERVO criteria, and this has been more clearly articulated in the revised manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003eBoth authors declare no compet\u0026shy;ing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAndresen JL, Ledet T, Hager H, Josephsen K, Ehlers N (2002) The influence of corneal stromal matrix proteins on the migration of human corneal fibroblasts. Exp Eye Res 71(1):33\u0026ndash;43. https://doi.org/10.1006/exer.2000.0850 \u003c/li\u003e\n\u003cli\u003eChiarad\u0026iacute;a P, Tytiun A, Botta MJ, Albornoz S, Huarte L, Abuin L (2010) Uso de membrana amni\u0026oacute;tica en reconstrucci\u0026oacute;n de superficie ocular: resultados preliminares. Oftalmol Clin Exp 4(2):64\u0026ndash;68 https://oftalmologos.org.ar/oce_anteriores/files/original/502c7e2bc34f6025af9d37357958da83.pdf \u003c/li\u003e\n\u003cli\u003eChoi YS, Kim JY, Wee WR, Lee JH (1998) Effect of application of human amniotic membrane on rabbit corneal wound healing after excimer laser photorefractive keratectomy. Cornea 17:389\u0026ndash;395. https://doi.org/10.1097/00003226-199807000-00009 \u003c/li\u003e\n\u003cli\u003eChow DWY, Westermeyer HD (2015) Retrospective evaluation of corneal reconstruction using ACell VetTM alone in dogs and cats: 82 cases. Vet Ophthalmol:1\u0026ndash;10. https://doi.org/10.1111/vop.12294 \u003c/li\u003e\n\u003cli\u003eCognard S, Barnouin L, Bosc J, Gindraux F, Robin MC, Douet JY, Thuret G (2022) New devitalized freeze-dried human umbilical cord amniotic membrane as an innovative treatment of ocular surface defects: preclinical results. J Funct Biomater 13(3):150. https://doi.org/10.3390/jfb13030150 \u003c/li\u003e\n\u003cli\u003eEspana EM, Prabhasawat P, Grueterich M, Solomon A, Tseng SC (2002) Amniotic membrane transplantation for reconstruction after excision of large ocular surface neoplasias. Br J Ophthalmol 86:640\u0026ndash;645. https://doi.org/10.1136/bjo.86.6.640 \u003c/li\u003e\n\u003cli\u003eFontenla JR, V\u0026aacute;zquez X, D\u0026iacute;az P, Gatell J, Pita D (2003) Membrana amni\u0026oacute;tica. Caracter\u0026iacute;sticas, efectos y aplicaciones en oftalmolog\u0026iacute;a. CTS\u003cem\u003e \u003c/em\u003e64:587\u0026ndash;601\u003c/li\u003e\n\u003cli\u003eGelatt KN, Gelatt JP, Plummer C (2022a) Surgical procedures for the conjunctiva and the nictitating membrane. In: Veterinary Ophthalmic Surgery. Second edition (Ed. Elsevier)\u003c/li\u003e\n\u003cli\u003eGelatt KN, Gelatt JP, Plummer C (2022b) Surgery of the cornea and sclera. In: Veterinary Ophthalmic Surgery. Second edition (Ed. Elsevier)\u003c/li\u003e\n\u003cli\u003eHerrera D. Enfermedades de la c\u0026oacute;rnea (2007) In: Daniel H. Oftalmolog\u0026iacute;a cl\u0026iacute;nica en animales. Schering-plough.1st ed. Buenos Aires: Inter-M\u0026eacute;dica, pp 113\u0026ndash;144\u003c/li\u003e\n\u003cli\u003eJain S, Rastogi A. Evaluation of the outcome of amniotic membrane transplantation for ocular surface reconstruction in symblepharon. \u003cem\u003eEye\u003c/em\u003e 2004;18:1251\u0026ndash;1257. https://doi.org/10.1038/sj.eye.6701379 \u003c/li\u003e\n\u003cli\u003eLee S-H, Tseng SCG (1997) Amniotic membrane transplantation for persistent epithelial defects with ulceration. Am J Ophthalmol 123:303\u0026ndash;312. https://doi.org/10.1016/S0002-9394(14)70125-4 \u003c/li\u003e\n\u003cli\u003eLekhanont K, Jongkhajornpong P, Anothaisintawee T, Chuckpaiwong V (2016) Undiluted serum eye drops for the treatment of persistent corneal epitheilal defects. Sci Rep.6:38143. https://doi.org/10.1038/srep38143 \u003c/li\u003e\n\u003cli\u003eMeneses C, Serna M (2000) Surgical techniques for the repair of deep ulcers of the cornea. Rev Vet Per\u0026uacute; 1(2):157\u0026ndash;162.\u003c/li\u003e\n\u003cli\u003ePe\u0026ntilde;a MT, Leiva M (2012) Claves cl\u0026iacute;nicas para el diagn\u0026oacute;stico y tratamiento de las \u0026uacute;lceras corneales en el perro. Clin Vet Peq Anim 32:15\u0026ndash;26. https://ddd.uab.cat/pub/clivetpeqani/clivetpeqani_a2012v32n1/clivetpeqaniv32n1p15.pdf \u003c/li\u003e\n\u003cli\u003eShin KS, Chung IY, Seo SW (2003) The effect of amniotic membrane transplantation for corneal ulcer and ocular surface diseases. J Korean Ophthalmol Soc 44:1305\u0026ndash;1310.\u003c/li\u003e\n\u003cli\u003eTamhane A, Vajpayee RB, Biswas NR, Pandey RM, Sharma N, Titiyal JS, Tandon R (2005) Evaluation of amniotic membrane transplantation as an adjunct to medical therapy as compared with medical therapy alone in acute ocular burns. Ophthalmology 112:1963\u0026ndash;1969. https://doi.org/10.1016/j.ophtha.2005.05.022 \u003c/li\u003e\n\u003cli\u003eTang GG, Ahn HB, Park WC (2003) The clinical effects of dye-amniotic membrane transplantation on bullous keratopathy. J Korean Ophthalmol Soc\u003cem\u003e \u003c/em\u003e44:1741\u0026ndash;1747.\u003c/li\u003e\n\u003cli\u003eTrujillo-Piso DY, Zamora-Restán WA, Padilla-Barreto MY (2016). Implantes de membranas biológicas en cirugía reconstructiva veterinaria: Aspectos básicos y métodos de conservación. Rev Med Vet 31:105\u0026ndash;120. http://www.scielo.org.co/pdf/rmv/n31/n31a11.pdf \u003c/li\u003e\n\u003cli\u003eWhitley RD (2000) Canine and feline primary ocular bacterial infections. Vet Clin North Am Small Anim 30:1151\u0026ndash;1167. https://doi.org/10.1016/S0195-5616(00)05012-9 \u003c/li\u003e\n\u003cli\u003eWiemer P, Gruys E, van Hoeck B (2005) Study of seven different types of grafts for jugular vein transplantation in the horse. Res Vet Sci\u003cem\u003e \u003c/em\u003e79(3):211\u0026ndash;217. https://doi.org/10.1016/j.rvsc.2004.12.005 \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"veterinary-research-communications","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"verc","sideBox":"Learn more about [Veterinary Research Communications](https://www.springer.com/journal/11259)","snPcode":"11259","submissionUrl":"https://submission.nature.com/new-submission/11259/3","title":"Veterinary Research Communications","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Cornea, Collagen, Descemetocele, Corneal Perforation, Leucoma, Re-Epithelialization","lastPublishedDoi":"10.21203/rs.3.rs-6733977/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6733977/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis retrospective study aimed to assess the effectiveness of 200 \u0026micro;m type I bovine skin-derived collagen membranes in treating deep and penetrating corneal ulcers in dogs. Twelve cases involving dogs with descemetocele and/or ocular perforation demonstrated advanced corneal stromal damage and compromised eye integrity. Two hundred-micrometer (200 \u0026micro;m) type I bovine skin-derived collagen membranes were inserted into the corneal lesion, which was protected with a 360-degree conjunctival flap, followed by tarsorrhaphy. Evaluations were conducted on days 15, 30, and 60 via a self-designed V-injury score scale. By day 15, patients exhibited significant improvement, with stable intraocular pressure (IOP) and the absence of pain. All patients displayed episcleritis, moderate conjunctival inflammation, and diffuse corneal edema. The score was II in 10 dogs without limbal involvement but with moderate edema. Two dogs had a Grade III injury score with corneal edema exceeding 50% and moderate limbal involvement. By day 30, all patients had remodeled the corneal defect with stable IOPs, but three had moderate edema and superficial vascularization. On day 60, stable IOPs were observed, with four patients developing simple leucoma without involvement with the visual axis or active corneal alteration. The use of 200 \u0026micro;m type I bovine skin-derived collagen membranes, with a 360-degree conjunctival flap and temporary tarsorrhaphy, proves to be an excellent adjuvant in the healing process of deep and perforating corneal lesions in dogs. This combination facilitates corneal remodeling, reducing adverse scarring.\u003c/p\u003e","manuscriptTitle":"Use of type I bovine collagen membranes for treating deep and perforating corneal ulcers in brachycephalic dogs","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-30 16:17:59","doi":"10.21203/rs.3.rs-6733977/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-06-01T21:46:59+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-29T17:15:01+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"193773067133383381677298563621354799406","date":"2025-05-27T23:52:59+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-05-27T19:47:11+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-05-26T05:11:40+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-05-26T05:09:41+00:00","index":"","fulltext":""},{"type":"submitted","content":"Veterinary Research Communications","date":"2025-05-23T14:49:04+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"veterinary-research-communications","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"verc","sideBox":"Learn more about [Veterinary Research Communications](https://www.springer.com/journal/11259)","snPcode":"11259","submissionUrl":"https://submission.nature.com/new-submission/11259/3","title":"Veterinary Research Communications","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"cf50440b-c113-46bb-a70f-fdbe4e0508d1","owner":[],"postedDate":"May 30th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-08-04T16:44:21+00:00","versionOfRecord":{"articleIdentity":"rs-6733977","link":"https://doi.org/10.1007/s11259-025-10829-2","journal":{"identity":"veterinary-research-communications","isVorOnly":false,"title":"Veterinary Research Communications"},"publishedOn":"2025-07-30 16:13:28","publishedOnDateReadable":"July 30th, 2025"},"versionCreatedAt":"2025-05-30 16:17:59","video":"","vorDoi":"10.1007/s11259-025-10829-2","vorDoiUrl":"https://doi.org/10.1007/s11259-025-10829-2","workflowStages":[]},"version":"v1","identity":"rs-6733977","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6733977","identity":"rs-6733977","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}