Penetrating Canaloplasty Combined with Anterior Vitrectomy and Partial Ciliary Body Cauterization for Secondary Angle-Closure Glaucoma in Nanophthalmos: A Two-Case Report

Penetrating Canaloplasty Combined with Anterior Vitrectomy and Partial Ciliary Body Cauterization for Secondary Angle-Closure Glaucoma in Nanophthalmos: A Two-Case Report | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Penetrating Canaloplasty Combined with Anterior Vitrectomy and Partial Ciliary Body Cauterization for Secondary Angle-Closure Glaucoma in Nanophthalmos: A Two-Case Report Ping Yu, Zhengfang Wu, Suju Liu, Jing Shu, Xiao Tang, Yifei Yu, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7381786/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 8 You are reading this latest preprint version Abstract Background Nanophthalmos (NO) is a rare congenital condition often associated with secondary angle-closure glaucoma. Due to structural abnormalities, nanophthalmic eyes are prone to serious postoperative complications such as uveal effusion, malignant glaucoma, and explosive suprachoroidal hemorrhage following filtering surgeries. Penetrating canaloplasty (PCP) is a modified version of canaloplasty (CP) and a minimally invasive glaucoma surgery (MIGS) that does not rely on a filtering bleb. It is not limited by angle anatomy and has broad indications, making it particularly suitable for angle-closure glaucoma. This report presents two cases treated with PCP combined with anterior vitrectomy and partial ciliary body cauterization, highlighting the potential therapeutic value of this surgical approach in eyes with complex anterior segment anatomy and strategies for managing postoperative complications. Case presentation We report two cases of NO with secondary angle-closure glaucoma, both of whom underwent bilateral penetrating canaloplasty combined with anterior vitrectomy and partial ciliary body cauterization. Postoperative follow-up durations were 3 and 7 months, respectively. Intraocular pressure (IOP) remained well controlled in both patients without the need for additional antiglaucoma medications. One case showed no significant postoperative complications, while the other developed choroidal detachment, which resolved well with conservative treatment. Conclusions PCP combined with anterior vitrectomy and partial ciliary body cauterization may be a feasible option for managing secondary angle-closure glaucoma in nanophthalmic eyes. It provides effective IOP control without blebs. The differing postoperative recoveries of the two patients prompt further reflection on individual anatomical variations and potential risk factors—such as axial length and gender—that may influence surgical outcomes. Emphasizes the importance of comprehensive preoperative evaluation and risk management. Nanophthalmos (NO) Secondary angle-closure glaucoma Penetrating canaloplasty (PCP) Anterior vitrectomy Ciliary body cauterization Minimally invasive glaucoma surgery (MIGS) Figures Figure 1 Figure 2 Figure 3 Figure 4 Background Nanophthalmos (NO) is a rare congenital ocular malformation characterized by a crowded anterior segment, with features including markedly short axial length (AL < 20 mm), shallow anterior chamber, and a high lens-to-eye volume ratio[ 1 , 2 ]. These anatomical abnormalities predispose patients to angle closure and significantly increase the risk of developing secondary angle-closure glaucoma[ 3 ]. Furthermore, Due to the unique ocular anatomy, patients with NO are more prone to severe complications—such as choroidal detachment, malignant glaucoma, and expulsive choroidal hemorrhage—when undergoing conventional glaucoma filtration surgeries[ 4 , 5 ]. If not properly managed, these complications can lead to vision loss. Penetrating Canaloplasty (PCP) is a minimally invasive glaucoma surgery (MIGS) based on Schlemm’s canal that does not rely on filtration blebs. It was first proposed in China in 2015 and has since been widely adopted. As a modified version of traditional canaloplasty (CP), PCP involves deeper scleral dissection and excision of part of the trabecular meshwork and peripheral iris, thereby establishing a direct communication between the anterior chamber and Schlemm’s canal to enhance aqueous outflow through multiple pathways and reduce intraocular pressure (IOP). This direct connection between the anterior chamber and Schlemm’s canal allows PCP to remain operable even under complex anterior segment conditions such as angle closure, peripheral anterior synechiae, or corneal opacity. Unlike most MIGS procedures, which are limited to open-angle glaucoma, PCP is applicable to both open- and angle-closure glaucoma[ 6 ], and has also shown potential in treating certain refractory glaucoma such as iridocorneal endothelial syndrome[ 7 , 8 ]. Moreover, PCP does not create a filtration bleb postoperatively, thereby significantly reducing conjunctival trauma and bleb-related complications compared to conventional trabeculectomy. Previous studies have demonstrated that PCP achieves IOP-lowering efficacy comparable to trabeculectomy[ 9 ], while offering advantages over CP in terms of reduced postoperative medication use and improved surgical success rates [ 10 , 11 ]. Based on the anatomical advantages of PCP in the treatment of angle-closure glaucoma, this study represents the first attempt to apply the PCP technique to such cases, in combination with anterior vitrectomy and partial ciliary body cauterization, aiming to provide new insights and clinical reference for the surgical management of these complex patients. Case presentation Case 1 A 35-year-old male patient with NO complicated by secondary angle-closure glaucoma had previously recorded maximum IOP of 50 mmHg in the right eye (OD) and 44 mmHg in the left eye (OS). He had been on long-term topical therapy with timolol, brinzolamide, brimonidine, and tafluprost eye drops with IOP fluctuating between 15 and 26 mmHg. Upon admission, the patient’s uncorrected distance visual acuity (UDVA) was counting fingers at 20 cm OD and hand motion at 50 cm OS, with no improvement upon refraction. Refraction was +8.25 diopters sphere (DS)/−0.75 diopters cylinder (DC) ×140° OD, and +7.75 DS OS. Slit-lamp examination revealed clear corneas, shallow anterior chambers in both eyes (OU), pupils approximately 3 mm in diameter with intact light reflexes, and transparent lenses. Fundus examination demonstrated pale optic discs with a cup-to-disc ratio (C/D) of 1.0 bilaterally, and absence of the central foveal reflex. Spaeth angle grading was A20b OU. Axial lengths (ALs) were 18.74 mm OD and 18.68 mm OS. Ultrasound biomicroscopy (UBM) revealed a central anterior chamber depth of 1.99 mm OD and 2.02 mm OS, with angle closure OU. Corneal thickness (CCT) measured 504 μm OD and 513 μm OS. Visual field testing revealed superior arcuate defects OU. Optical Coherence Tomography (OCT) and Optical Coherence Tomography Angiography (OCTA) revealed thinning of the retinal nerve fiber layer (RNFL) and reduced peripapillary blood flow density in both eyes. Macular OCT revealed macular edema in both eyes. B-scan ultrasonography indicated thickening of the sclera in both eyes. The patient underwent bilateral PCP combined with anterior vitrectomy and partial ciliary body cauterization surgery (Fig. 1). On postoperative day 1(Fig. 2), without the use of any intraocular pressure-lowering medications, the intraocular pressure was 19 mmHg in the right eye and 15 mmHg in the left eye. Visual acuity remained unchanged in both eyes. Postoperatively, the patient was treated with Tobradex ointment once nightly, discontinued after 3 days; prednisolone eye drops 4 times daily, reduced by one drop per week and discontinued after 1 month; levofloxacin eye drops 4 times daily, discontinued after 1 month; and diclofenac sodium eye drops 4 times daily, discontinued after 3 months. Pilocarpine eye drops were added one week after surgery and continued for 3 months. At 1 month postoperatively (Fig. 2), the IOP was 15 mmHg in both eyes. At 3 months, the IOP was 16 mmHg in the right eye and 14 mmHg in the left eye. At 6 months, the IOP was 18 mmHg in the right eye and 17 mmHg in the left eye. Without the use of any IOP-lowering medications, intraocular pressure remained well controlled postoperatively, and no complications such as malignant glaucoma or choroidal detachment were observed (Fig. 3). Case 2 A 35-year-old female patient with NO complicated by secondary angle-closure glaucoma had previously recorded maximum intraocular pressures (IOP) of 35 mmHg OD and 38 mmHg OS. She had been on long-term topical therapy with carteolol, brinzolamide, brimonidine and tafluprost eye drops with IOP fluctuating between 19 and 25 mmHg. Upon admission, the patient’s UDVA was 0.06 with BCVA of 0.5 OD, and 0.06 with BCVA of 0.3 OS. Refraction was +9.00 DS/−0.50 DC ×140° OD, and +8.50 DS OS. Slit-lamp examination revealed clear corneas, shallow anterior chambers OU, pupils approximately 4.5 mm in diameter with intact light reflexes, and transparent lenses. Fundus examination demonstrated pale optic discs with C/D of 1.0 bilaterally, and absence of the central foveal reflex. Spaeth angle grading was A15b OU. Axial lengths (ALs) were 17.76 mm OD and 17.61 mm OS. UBM revealed a central anterior chamber depth of 1.67 mm OD and 1.72 mm OS, with angle closure OU. Corneal thickness (CCT) measured 514 μm OD and 516 μm OS. Visual field testing revealed superior arcuate defects OU. OCT and OCTA revealed thinning of the RNFL and reduced peripapillary blood flow density in both eyes. The patient underwent bilateral PCP surgery. On postoperative day 1, the IOP was 28 mmHg in the right eye and 12 mmHg in the left eye. Visual acuity in the right eye remained unchanged, while the BCVA in the left eye was 0.15. The left eye showed an extremely shallow anterior chamber with peripheral anterior chamber obliteration and peripheral choroidal detachment observed in the fundus (Fig. 4). In addition to the standard postoperative regimen of corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), and antibiotic eye drops (same protocol as in Case 1), additional treatments were administered: IOP-lowering therapy with pilocarpine was added to the right eye; the left eye received pressure patching, enhanced anti-inflammatory and mydriatic therapy, including tropicamide eye drops four times daily and atropine ointment once nightly. A subconjunctival injection of compound mydriatic and dexamethasone sodium phosphate was administered, along with intravenous infusion of dexamethasone sodium phosphate (15 mg once daily) and mannitol (250 ml once daily). After two weeks of treatment, the choroidal detachment in the left eye gradually resolved, and the patient was transitioned to oral corticosteroids and subsequently discharged. At 1 month postoperatively, the IOP was 19 mmHg in the right eye and 17 mmHg in the left eye. The choroidal detachment in the left eye continued to improve. The patient was advised to discontinue IOP-lowering medication in the right eye and continue oral corticosteroids. At 3 months postoperatively, the IOP was 17 mmHg in the right eye and 16 mmHg in the left eye. BCVA was 0.5 in the right eye and 0.2 in the left eye. Refraction was +9.00 DS/−0.75 DC ×140° OD and +11.00 DS/−2.25 DC ×180° OS. Fundus examination showed that the choroid and retina of the left eye had returned to a flattened state (Fig. 4). Discussion This report presents two cases of nanophthalmic eyes with secondary angle-closure glaucoma successfully treated with PCP combined with anterior vitrectomy and partial ciliary body cauterization. Both cases demonstrated favorable IOP control without the need for postoperative antiglaucoma medications. However, notable differences in postoperative outcomes between the two patients provide valuable insights into risk stratification and management strategies in this high-risk population. The male patient (Case 1) experienced an uneventful postoperative course. IOP remained stable between 15–18 mmHg during the 6-month follow-up, and no complications were observed. In contrast, the female patient (Case 2) developed significant postoperative complications, including choroidal detachment and extremely shallow anterior chamber in the left eye. Although this condition resolved with timely and intensive conservative treatment, it underscores the higher risk of postoperative complications in certain nanophthalmic patients. Several factors may account for the differences in clinical outcomes between these two patients. First and foremost, AL is a critical anatomical determinant in NO-related surgical risks. The female patient had shorter axial lengths (17.76 mm OD, 17.61 mm OS) compared to the male patient (18.74 mm OD, 18.68 mm OS), which may have predisposed her to more severe postoperative anatomical instability. It is well-established that the risk of choroidal detachment and malignant glaucoma increases exponentially as axial length decreases, particularly when AL < 18 mm[ 12 , 13 ]. The shorter AL in Case 2 likely contributed to the postoperative anterior segment shallowing and choroidal effusion. Second, gender may play a role in the predisposition to complications. Studies have shown that female patients with NO are more prone to developing uveal effusion and other complications due to a higher frequency of extreme anatomical crowding and thinner scleral architecture Although both patients underwent the same surgical technique and perioperative regimen, the female patient’s more fragile ocular anatomy may have exacerbated the intraocular fluid dynamic imbalance during the early postoperative period[ 14 ]. Despite these risks, both patients ultimately achieved satisfactory IOP control without the need for topical antiglaucoma medications. This highlights the efficacy of PCP in restoring physiological aqueous outflow, even in the presence of extreme anatomical crowding. PCP, aimed at enhancing internal aqueous drainage, entails externally opening Schlemm’s canal to establish direct communication with the anterior chamber—regardless of anterior chamber angle status—by excising part of the trabecular meshwork (or deep corneoscleral tissue) and the peripheral iris. By creating a direct communication between Schlemm’s canal and the anterior chamber, and without reliance on a filtering bleb, PCP avoids many of the bleb-related complications that are common in traditional trabeculectomy[ 6 ]. Meanwhile, localized cauterization of the exposed hypertrophic partial ciliary body may help alleviate tissue-level obstruction at the sites of iridectomy and trabecular excision, preventing postoperative blockage of the aqueous outflow pathway caused by anterior displacement of the partial ciliary body, thereby enhancing postoperative aqueous humor drainage and improving the stability of surgical outcomes. Additionally, the adjunctive anterior vitrectomy may have contributed to anterior chamber deepening and reduced vitreous pressure, facilitating postoperative stabilization[ 15 ]. The favorable outcome in Case 2 also emphasizes the importance of close postoperative monitoring and prompt intervention. The use of systemic corticosteroids, osmotic agents, and mydriatic therapy proved effective in resolving choroidal detachment and restoring anterior chamber depth. These interventions should be considered standard components of the management algorithm for high-risk nanophthalmic eyes undergoing intraocular surgery. Nevertheless, several limitations must be acknowledged. First, the follow-up duration in both cases was relatively short (3–7 months), and long-term data on IOP stability, visual outcomes, and complication recurrence are still needed. Second, although both patients tolerated the surgery well and showed good outcomes, PCP in NO remains a technically demanding procedure that requires surgical expertise and individualized preoperative planning. Larger case series and prospective studies are necessary to validate these preliminary findings and to further refine patient selection criteria. Conclusions PCP combined with anterior vitrectomy and partial ciliary body cauterization appears to be a viable surgical option for managing secondary angle-closure glaucoma in nanophthalmic eyes. It offers effective IOP control without the need for filtering blebs and may minimize the risk of postoperative bleb-related complications. However, the distinct outcomes in our two cases underscore the importance of axial length and gender as potential risk factors. Shorter axial lengths, especially < 18 mm, may predict higher complication rates. Female patients may also warrant heightened intraoperative and postoperative vigilance. With early recognition and appropriate conservative treatment, complications such as choroidal detachment can be effectively managed. Further long-term studies with larger cohorts are needed to fully establish the safety profile and efficacy of PCP in this unique patient population. Abbreviations PCP Penetrating Canaloplasty NO Nanophthalmos IOP intraocular pressure Declarations Acknowledgements Not applicable Authors’ contributions P.Y. contributed to data collection and drafting the manuscript. Z.W. and S.L. performed the clinical examination and investigation. J.S., X.T., S.W. and Y.Y. contributed to patient interaction. L.Z. was the operating surgeon for the patients and participated in the revision and review of the manuscript. All authors read and approved the final manuscript. Funding No funding was received for this study. Data availability All data generated or analyzed during this study are included in this published article. Ethics approval and consent to participate This study was approved by the Medical Ethic Review Committee of Chengdu First People’s Hospital and adhered to the tenets of the Declaration of Helsinki. Consent for publication Informed written consent was obtained from both patients, agreeing that their personal or clinical details along with any identifying images to be published in this study. Competing interests The authors declare no competing interests. References Fernández-Vigo JI, Rodríguez-Quet O, Montolío-Marzo E, Burgos-Blasco B, Kudsieh B, González-Martin-Moro J, García-Feijóo J. Anterior Scleral Thickness and Other Dimensions in Nanophthalmos by Swept-Source Optical Coherence Tomography: A Comparative Study. J Clin Med 2023, 12(17). Shah SP, Taylor AE, Sowden JC, Ragge N, Russell-Eggitt I, Rahi JS, Gilbert CE. Anophthalmos, microphthalmos, and Coloboma in the United kingdom: clinical features, results of investigations, and early management. Ophthalmology. 2012;119(2):362–8. 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Retrocorneal membrane interception enhanced penetrating canaloplasty for patients with open angle glaucoma secondary to ICE syndrome. Int Ophthalmol. 2024;44(1):395. Ye W, Zhang S, Zhu S, Li J, Gu J, Zhao M, Jiang K, Xie Y, Le R, Zhou W, et al. 24-month prospective randomized comparison of ab externo penetrating canaloplasty versus trabeculectomy in primary angle-closure glaucoma. Asia Pac J Ophthalmol (Phila). 2025;14(3):100167. Ye W, Xu X, Lin H, Li J, Zhu S, Xie Y, Zhang S, Liang Y. Efficacy of Penetrating Canaloplasty versus Trabeculectomy in Patients with Bilateral Primary Glaucoma: A Self-Control Study. Ophthalmic Res. 2025;68(1):310–9. Ye W, Li J, Zhang S, Zhu S, Xie Y, Le R, Zhou W, He M, Wang N, Liang Y. Efficacy and safety of penetrating canaloplasty versus ab externo canaloplasty for primary open-angle glaucoma: A randomized controlled trial. Acta Ophthalmol. 2025;103(1):e58–65. Wu W, Dawson DG, Sugar A, Elner SG, Meyer KA, McKey JB, Moroi SE. Cataract surgery in patients with nanophthalmos: results and complications. J Cataract Refract Surg. 2004;30(3):584–90. Tailor R, Ng AT, Murthy S. Cataract surgery in patients with nanophthalmos. Ophthalmology. 2014;121(2):e11. Carricondo PC, Andrade T, Prasov L, Ayres BM, Moroi SE. Nanophthalmos: A Review of the Clinical Spectrum and Genetics. J Ophthalmol. 2018;2018:2735465. Faisal AA, Kamaruddin MI, Toda R, Kiuchi Y. Successful recovery from misdirection syndrome in nanophthalmic eyes by performing an anterior vitrectomy through the anterior chamber. Int Ophthalmol. 2019;39(2):347–57. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 26 Sep, 2025 Reviewers agreed at journal 17 Sep, 2025 Reviewers agreed at journal 15 Sep, 2025 Reviewers invited by journal 15 Sep, 2025 Editor invited by journal 19 Aug, 2025 Editor assigned by journal 17 Aug, 2025 Submission checks completed at journal 17 Aug, 2025 First submitted to journal 15 Aug, 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-7381786","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":516394003,"identity":"1d0d0047-1600-4174-9e50-4a6da0a9171b","order_by":0,"name":"Ping Yu","email":"","orcid":"","institution":"Chengdu First People’s Hospital","correspondingAuthor":false,"prefix":"","firstName":"Ping","middleName":"","lastName":"Yu","suffix":""},{"id":516394004,"identity":"56cdf49f-026f-4420-a7a9-4e1d448e730c","order_by":1,"name":"Zhengfang Wu","email":"","orcid":"","institution":"University of TCM","correspondingAuthor":false,"prefix":"","firstName":"Zhengfang","middleName":"","lastName":"Wu","suffix":""},{"id":516394005,"identity":"8c2062ce-f742-4b6d-8de4-27f096c51a89","order_by":2,"name":"Suju Liu","email":"","orcid":"","institution":"University of TCM","correspondingAuthor":false,"prefix":"","firstName":"Suju","middleName":"","lastName":"Liu","suffix":""},{"id":516394006,"identity":"609ae21a-39b5-4531-8630-230bced4886b","order_by":3,"name":"Jing Shu","email":"","orcid":"","institution":"Chengdu First People’s Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jing","middleName":"","lastName":"Shu","suffix":""},{"id":516394007,"identity":"a74e85da-edbf-41d3-b99d-51650d80c70d","order_by":4,"name":"Xiao Tang","email":"","orcid":"","institution":"Chengdu First People’s Hospital","correspondingAuthor":false,"prefix":"","firstName":"Xiao","middleName":"","lastName":"Tang","suffix":""},{"id":516394008,"identity":"e2be928d-4ebb-4120-8dde-576897fb464d","order_by":5,"name":"Yifei Yu","email":"","orcid":"","institution":"Chengdu First People’s Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yifei","middleName":"","lastName":"Yu","suffix":""},{"id":516394009,"identity":"f98d8b62-c613-4341-9dc9-9f3812fe689d","order_by":6,"name":"Suzhen Wang","email":"","orcid":"","institution":"Chengdu First People’s Hospital","correspondingAuthor":false,"prefix":"","firstName":"Suzhen","middleName":"","lastName":"Wang","suffix":""},{"id":516394010,"identity":"9438cad1-d6d6-4ce2-bd11-015347680dc0","order_by":7,"name":"Zeng. 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07:55:33","extension":"html","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":60059,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7381786/v1/5ec5810a7d00b3bc2947b0f8.html"},{"id":91960620,"identity":"4756fc5c-c8f8-40e6-881f-5c85209b719b","added_by":"auto","created_at":"2025-09-23 07:47:33","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":946323,"visible":true,"origin":"","legend":"\u003cp\u003eKey Surgical Steps. \u003cstrong\u003eA \u003c/strong\u003eCreation of a superficial scleral flap, approximately 4×4 mm. \u003cstrong\u003eB \u003c/strong\u003eCreation of a deep scleral flap, approximately 3×3 mm. \u003cstrong\u003eC \u003c/strong\u003eInsertion of an illuminated microcatheter into Schlemm’s canal. \u003cstrong\u003eD \u003c/strong\u003eFixation of the suture to the tip of the microcatheter (iTrack 250, Ellex iScience, USA). \u003cstrong\u003eE \u003c/strong\u003eWhile withdrawing the microcatheter, the suture is delivered into Schlemm’s canal. The illuminated tip of the microcatheter allows real-time intraoperative visualization of its position within Schlemm’s canal. \u003cstrong\u003eF \u003c/strong\u003eExcision of juxtacanalicular trabecular meshwork and corneoscleral tissue. \u003cstrong\u003eG\u003c/strong\u003e Excision of part of the peripheral iris. \u003cstrong\u003eH\u003c/strong\u003e Only the partial ciliary body exposed after iridectomy is cauterized. \u003cstrong\u003eI \u003c/strong\u003eAnterior vitrectomy through the iridectomy site. \u003cstrong\u003eJ \u003c/strong\u003eThe suture within Schlemm’s canal is tied with appropriate tension. \u003cstrong\u003eK \u003c/strong\u003eWatertight closure of the superficial scleral flap with one adjustable and several interrupted sutures.\u003cstrong\u003e L \u003c/strong\u003eClosure of the conjunctival flap.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7381786/v1/866a6c38b8f9f53186c6369f.png"},{"id":91960618,"identity":"d8049265-ec62-47b6-9d5b-e4cec0aa50b1","added_by":"auto","created_at":"2025-09-23 07:47:33","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":321547,"visible":true,"origin":"","legend":"\u003cp\u003eAnterior segment of the right eye before and after surgery in Case 1. \u003cstrong\u003eA, B\u003c/strong\u003e Preoperative and postoperative day 1 anterior segment. \u003cstrong\u003eC, D\u003c/strong\u003e Conjunctival appearance at postoperative day 1 (C) and 1 month (D).\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7381786/v1/0b1c3177c1d3bbab0ebaddb3.png"},{"id":91962575,"identity":"1f58100f-b69a-491d-88d3-4ea039c50572","added_by":"auto","created_at":"2025-09-23 07:55:33","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":777045,"visible":true,"origin":"","legend":"\u003cp\u003eFundus before surgery and at 2 weeks postoperatively in Case 1.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7381786/v1/6629d684b8282118a1cb1d8b.png"},{"id":91960623,"identity":"78c2af27-c32d-494b-b0c1-3bd7fced507e","added_by":"auto","created_at":"2025-09-23 07:47:33","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":286921,"visible":true,"origin":"","legend":"\u003cp\u003eFundus images of the left eye before and after surgery in Case 2.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7381786/v1/103addbafab6fac6f0b15239.png"},{"id":91964486,"identity":"453f2053-3e07-42ab-bbdb-dac3fc00e5d0","added_by":"auto","created_at":"2025-09-23 08:11:55","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3997149,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7381786/v1/238ee2cd-8dd4-4c73-a572-4676c0e4a549.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Penetrating Canaloplasty Combined with Anterior Vitrectomy and Partial Ciliary Body Cauterization for Secondary Angle-Closure Glaucoma in Nanophthalmos: A Two-Case Report","fulltext":[{"header":"Background","content":"\u003cp\u003eNanophthalmos (NO) is a rare congenital ocular malformation characterized by a crowded anterior segment, with features including markedly short axial length (AL\u0026thinsp;\u0026lt;\u0026thinsp;20 mm), shallow anterior chamber, and a high lens-to-eye volume ratio[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. These anatomical abnormalities predispose patients to angle closure and significantly increase the risk of developing secondary angle-closure glaucoma[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Furthermore, Due to the unique ocular anatomy, patients with NO are more prone to severe complications\u0026mdash;such as choroidal detachment, malignant glaucoma, and expulsive choroidal hemorrhage\u0026mdash;when undergoing conventional glaucoma filtration surgeries[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. If not properly managed, these complications can lead to vision loss.\u003c/p\u003e\u003cp\u003ePenetrating Canaloplasty (PCP) is a minimally invasive glaucoma surgery (MIGS) based on Schlemm\u0026rsquo;s canal that does not rely on filtration blebs. It was first proposed in China in 2015 and has since been widely adopted. As a modified version of traditional canaloplasty (CP), PCP involves deeper scleral dissection and excision of part of the trabecular meshwork and peripheral iris, thereby establishing a direct communication between the anterior chamber and Schlemm\u0026rsquo;s canal to enhance aqueous outflow through multiple pathways and reduce intraocular pressure (IOP). This direct connection between the anterior chamber and Schlemm\u0026rsquo;s canal allows PCP to remain operable even under complex anterior segment conditions such as angle closure, peripheral anterior synechiae, or corneal opacity. Unlike most MIGS procedures, which are limited to open-angle glaucoma, PCP is applicable to both open- and angle-closure glaucoma[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], and has also shown potential in treating certain refractory glaucoma such as iridocorneal endothelial syndrome[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Moreover, PCP does not create a filtration bleb postoperatively, thereby significantly reducing conjunctival trauma and bleb-related complications compared to conventional trabeculectomy. Previous studies have demonstrated that PCP achieves IOP-lowering efficacy comparable to trabeculectomy[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], while offering advantages over CP in terms of reduced postoperative medication use and improved surgical success rates [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Based on the anatomical advantages of PCP in the treatment of angle-closure glaucoma, this study represents the first attempt to apply the PCP technique to such cases, in combination with anterior vitrectomy and partial ciliary body cauterization, aiming to provide new insights and clinical reference for the surgical management of these complex patients.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003e\u003cstrong\u003eCase 1\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 35-year-old male patient with NO complicated by secondary angle-closure glaucoma had previously recorded maximum IOP of 50 mmHg in the right eye (OD) and 44 mmHg in the left eye (OS). He had been on long-term topical therapy with timolol, brinzolamide, brimonidine, and tafluprost eye drops with IOP fluctuating between 15 and 26 mmHg. Upon admission, the patient\u0026rsquo;s uncorrected distance visual acuity (UDVA) was counting fingers at 20 cm OD and hand motion at 50 cm OS, with no improvement upon refraction. Refraction was +8.25 diopters sphere (DS)/\u0026minus;0.75 diopters cylinder (DC) \u0026times;140\u0026deg; OD, and +7.75 DS OS. Slit-lamp examination revealed clear corneas, shallow anterior chambers in both eyes (OU), pupils approximately 3 mm in diameter with intact light reflexes, and transparent lenses. Fundus examination demonstrated pale optic discs with a cup-to-disc ratio (C/D) of 1.0 bilaterally, and absence of the central foveal reflex. Spaeth angle grading was A20b OU. Axial lengths (ALs) were 18.74 mm OD and 18.68 mm OS. Ultrasound biomicroscopy (UBM) revealed a central anterior chamber depth of 1.99 mm OD and 2.02 mm OS, with angle closure OU. Corneal thickness (CCT) measured 504 \u0026mu;m OD and 513 \u0026mu;m OS. Visual field testing revealed superior arcuate defects OU. Optical Coherence Tomography (OCT) and Optical Coherence Tomography Angiography (OCTA) revealed thinning of the retinal nerve fiber layer (RNFL) and reduced peripapillary blood flow density in both eyes. Macular OCT revealed macular edema in both eyes. B-scan ultrasonography indicated thickening of the sclera in both eyes. The patient underwent bilateral PCP combined with anterior vitrectomy and partial ciliary body cauterization surgery (Fig. 1).\u003c/p\u003e\n\u003cp\u003eOn postoperative day 1(Fig. 2), without the use of any intraocular pressure-lowering medications, the intraocular pressure was 19 mmHg in the right eye and 15 mmHg in the left eye. Visual acuity remained unchanged in both eyes. Postoperatively, the patient was treated with Tobradex ointment once nightly, discontinued after 3 days; prednisolone eye drops 4 times daily, reduced by one drop per week and discontinued after 1 month; levofloxacin eye drops 4 times daily, discontinued after 1 month; and diclofenac sodium eye drops 4 times daily, discontinued after 3 months. Pilocarpine eye drops were added one week after surgery and continued for 3 months.\u003c/p\u003e\n\u003cp\u003eAt 1 month postoperatively (Fig. 2), the IOP was 15 mmHg in both eyes. At 3 months, the IOP was 16 mmHg in the right eye and 14 mmHg in the left eye. At 6 months, the IOP was 18 mmHg in the right eye and 17 mmHg in the left eye. Without the use of any IOP-lowering medications, intraocular pressure remained well controlled postoperatively, and no complications such as malignant glaucoma or choroidal detachment were observed (Fig. 3).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase 2\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 35-year-old female patient with NO complicated by secondary angle-closure glaucoma had previously recorded maximum intraocular pressures (IOP) of 35 mmHg OD and 38 mmHg OS. She had been on long-term topical therapy with carteolol, brinzolamide, brimonidine and tafluprost eye drops with IOP fluctuating between 19 and 25 mmHg. Upon admission, the patient\u0026rsquo;s UDVA was 0.06 with BCVA of 0.5 OD, and 0.06 with BCVA of 0.3 OS. Refraction was +9.00 DS/\u0026minus;0.50 DC \u0026times;140\u0026deg; OD, and +8.50 DS OS. Slit-lamp examination revealed clear corneas, shallow anterior chambers OU, pupils approximately 4.5 mm in diameter with intact light reflexes, and transparent lenses. Fundus examination demonstrated pale optic discs with C/D of 1.0 bilaterally, and absence of the central foveal reflex. Spaeth angle grading was A15b OU. Axial lengths (ALs) were 17.76 mm OD and 17.61 mm OS. UBM revealed a central anterior chamber depth of 1.67 mm OD and 1.72 mm OS, with angle closure OU. Corneal thickness (CCT) measured 514 \u0026mu;m OD and 516 \u0026mu;m OS. Visual field testing revealed superior arcuate defects OU. OCT and OCTA revealed thinning of the RNFL and reduced peripapillary blood flow density in both eyes. The patient underwent bilateral PCP surgery.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; On postoperative day 1, the IOP was 28 mmHg in the right eye and 12 mmHg in the left eye. Visual acuity in the right eye remained unchanged, while the BCVA in the left eye was 0.15. The left eye showed an extremely shallow anterior chamber with peripheral anterior chamber obliteration and peripheral choroidal detachment observed in the fundus (Fig. 4). In addition to the standard postoperative regimen of corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), and antibiotic eye drops (same protocol as in Case 1), additional treatments were administered: IOP-lowering therapy with pilocarpine was added to the right eye; the left eye received pressure patching, enhanced anti-inflammatory and mydriatic therapy, including tropicamide eye drops four times daily and atropine ointment once nightly. A subconjunctival injection of compound mydriatic and dexamethasone sodium phosphate was administered, along with intravenous infusion of dexamethasone sodium phosphate (15 mg once daily) and mannitol (250 ml once daily). After two weeks of treatment, the choroidal detachment in the left eye gradually resolved, and the patient was transitioned to oral corticosteroids and subsequently discharged.\u003c/p\u003e\n\u003cp\u003eAt 1 month postoperatively, the IOP was 19 mmHg in the right eye and 17 mmHg in the left eye. The choroidal detachment in the left eye continued to improve. The patient was advised to discontinue IOP-lowering medication in the right eye and continue oral corticosteroids. At 3 months postoperatively, the IOP was 17 mmHg in the right eye and 16 mmHg in the left eye. BCVA was 0.5 in the right eye and 0.2 in the left eye. Refraction was +9.00 DS/\u0026minus;0.75 DC \u0026times;140\u0026deg; OD and +11.00 DS/\u0026minus;2.25 DC \u0026times;180\u0026deg; OS. Fundus examination showed that the choroid and retina of the left eye had returned to a flattened state (Fig. 4).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis report presents two cases of nanophthalmic eyes with secondary angle-closure glaucoma successfully treated with PCP combined with anterior vitrectomy and partial ciliary body cauterization. Both cases demonstrated favorable IOP control without the need for postoperative antiglaucoma medications. However, notable differences in postoperative outcomes between the two patients provide valuable insights into risk stratification and management strategies in this high-risk population.\u003c/p\u003e\u003cp\u003eThe male patient (Case 1) experienced an uneventful postoperative course. IOP remained stable between 15\u0026ndash;18 mmHg during the 6-month follow-up, and no complications were observed. In contrast, the female patient (Case 2) developed significant postoperative complications, including choroidal detachment and extremely shallow anterior chamber in the left eye. Although this condition resolved with timely and intensive conservative treatment, it underscores the higher risk of postoperative complications in certain nanophthalmic patients.\u003c/p\u003e\u003cp\u003eSeveral factors may account for the differences in clinical outcomes between these two patients. First and foremost, AL is a critical anatomical determinant in NO-related surgical risks. The female patient had shorter axial lengths (17.76 mm OD, 17.61 mm OS) compared to the male patient (18.74 mm OD, 18.68 mm OS), which may have predisposed her to more severe postoperative anatomical instability. It is well-established that the risk of choroidal detachment and malignant glaucoma increases exponentially as axial length decreases, particularly when AL\u0026thinsp;\u0026lt;\u0026thinsp;18 mm[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The shorter AL in Case 2 likely contributed to the postoperative anterior segment shallowing and choroidal effusion.\u003c/p\u003e\u003cp\u003eSecond, gender may play a role in the predisposition to complications. Studies have shown that female patients with NO are more prone to developing uveal effusion and other complications due to a higher frequency of extreme anatomical crowding and thinner scleral architecture Although both patients underwent the same surgical technique and perioperative regimen, the female patient\u0026rsquo;s more fragile ocular anatomy may have exacerbated the intraocular fluid dynamic imbalance during the early postoperative period[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eDespite these risks, both patients ultimately achieved satisfactory IOP control without the need for topical antiglaucoma medications. This highlights the efficacy of PCP in restoring physiological aqueous outflow, even in the presence of extreme anatomical crowding. PCP, aimed at enhancing internal aqueous drainage, entails externally opening Schlemm\u0026rsquo;s canal to establish direct communication with the anterior chamber\u0026mdash;regardless of anterior chamber angle status\u0026mdash;by excising part of the trabecular meshwork (or deep corneoscleral tissue) and the peripheral iris. By creating a direct communication between Schlemm\u0026rsquo;s canal and the anterior chamber, and without reliance on a filtering bleb, PCP avoids many of the bleb-related complications that are common in traditional trabeculectomy[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Meanwhile, localized cauterization of the exposed hypertrophic partial ciliary body may help alleviate tissue-level obstruction at the sites of iridectomy and trabecular excision, preventing postoperative blockage of the aqueous outflow pathway caused by anterior displacement of the partial ciliary body, thereby enhancing postoperative aqueous humor drainage and improving the stability of surgical outcomes. Additionally, the adjunctive anterior vitrectomy may have contributed to anterior chamber deepening and reduced vitreous pressure, facilitating postoperative stabilization[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe favorable outcome in Case 2 also emphasizes the importance of close postoperative monitoring and prompt intervention. The use of systemic corticosteroids, osmotic agents, and mydriatic therapy proved effective in resolving choroidal detachment and restoring anterior chamber depth. These interventions should be considered standard components of the management algorithm for high-risk nanophthalmic eyes undergoing intraocular surgery.\u003c/p\u003e\u003cp\u003eNevertheless, several limitations must be acknowledged. First, the follow-up duration in both cases was relatively short (3\u0026ndash;7 months), and long-term data on IOP stability, visual outcomes, and complication recurrence are still needed. Second, although both patients tolerated the surgery well and showed good outcomes, PCP in NO remains a technically demanding procedure that requires surgical expertise and individualized preoperative planning. Larger case series and prospective studies are necessary to validate these preliminary findings and to further refine patient selection criteria.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003ePCP combined with anterior vitrectomy and partial ciliary body cauterization appears to be a viable surgical option for managing secondary angle-closure glaucoma in nanophthalmic eyes. It offers effective IOP control without the need for filtering blebs and may minimize the risk of postoperative bleb-related complications. However, the distinct outcomes in our two cases underscore the importance of axial length and gender as potential risk factors. Shorter axial lengths, especially\u0026thinsp;\u0026lt;\u0026thinsp;18 mm, may predict higher complication rates. Female patients may also warrant heightened intraoperative and postoperative vigilance. With early recognition and appropriate conservative treatment, complications such as choroidal detachment can be effectively managed. Further long-term studies with larger cohorts are needed to fully establish the safety profile and efficacy of PCP in this unique patient population.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003ePCP Penetrating Canaloplasty\u003c/p\u003e\n\u003cp\u003eNO Nanophthalmos\u003c/p\u003e\n\u003cp\u003eIOP intraocular pressure\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eP.Y. contributed to data collection and drafting the manuscript. Z.W. and S.L. performed the clinical examination and investigation. J.S., X.T., S.W. and Y.Y. contributed to patient interaction. L.Z. was the operating surgeon for the patients and participated in the revision and review of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo funding was received for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data generated or analyzed during this study are included in this published article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Medical Ethic Review Committee of Chengdu First People\u0026rsquo;s Hospital and adhered to the tenets of the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInformed written consent was obtained from both patients, agreeing that their personal or clinical details along with any identifying images to be published in this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eFern\u0026aacute;ndez-Vigo JI, Rodr\u0026iacute;guez-Quet O, Montol\u0026iacute;o-Marzo E, Burgos-Blasco B, Kudsieh B, Gonz\u0026aacute;lez-Martin-Moro J, Garc\u0026iacute;a-Feij\u0026oacute;o J. Anterior Scleral Thickness and Other Dimensions in Nanophthalmos by Swept-Source Optical Coherence Tomography: A Comparative Study. J Clin Med 2023, 12(17).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShah SP, Taylor AE, Sowden JC, Ragge N, Russell-Eggitt I, Rahi JS, Gilbert CE. Anophthalmos, microphthalmos, and Coloboma in the United kingdom: clinical features, results of investigations, and early management. Ophthalmology. 2012;119(2):362\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eO'Grady RB. Nanophthalmos. Am J Ophthalmol. 1971;71(6):1251\u0026ndash;3.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYang N, Jin S, Ma L, Liu J, Shan C, Zhao J. The Pathogenesis and Treatment of Complications in Nanophthalmos. J Ophthalmol. 2020;2020:6578750.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlly N, Ismail S, Alli HD. Prevalence of complications in eyes with nanophthalmos or microphthalmos: protocol for a systematic review and meta-analysis. Syst Rev. 2022;11(1):25.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhang S, Hu C, Cheng H, Gu J, Samuel K, Lin H, Deng Y, Xie Y, Hu J, Le R, et al. Efficacy of bleb-independent penetrating canaloplasty in primary angle-closure glaucoma: one-year results. Acta Ophthalmol. 2022;100(1):e213\u0026ndash;20.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTian X, Guo J, Liao J, He M, Shi Y, Tang L. Penetrating canaloplasty in angle-closure glaucoma secondary to iridocorneal endothelial syndrome following multiple failed filtering surgeries: A case report. Medicine. 2023;102(8):e32950.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhou M, Zhu S, Li H, Ye W, Xu S, Lin H, Li J, Chen J, Zhang S, Tham CC, et al. Retrocorneal membrane interception enhanced penetrating canaloplasty for patients with open angle glaucoma secondary to ICE syndrome. Int Ophthalmol. 2024;44(1):395.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYe W, Zhang S, Zhu S, Li J, Gu J, Zhao M, Jiang K, Xie Y, Le R, Zhou W, et al. 24-month prospective randomized comparison of ab externo penetrating canaloplasty versus trabeculectomy in primary angle-closure glaucoma. Asia Pac J Ophthalmol (Phila). 2025;14(3):100167.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYe W, Xu X, Lin H, Li J, Zhu S, Xie Y, Zhang S, Liang Y. Efficacy of Penetrating Canaloplasty versus Trabeculectomy in Patients with Bilateral Primary Glaucoma: A Self-Control Study. Ophthalmic Res. 2025;68(1):310\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYe W, Li J, Zhang S, Zhu S, Xie Y, Le R, Zhou W, He M, Wang N, Liang Y. Efficacy and safety of penetrating canaloplasty versus ab externo canaloplasty for primary open-angle glaucoma: A randomized controlled trial. Acta Ophthalmol. 2025;103(1):e58\u0026ndash;65.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWu W, Dawson DG, Sugar A, Elner SG, Meyer KA, McKey JB, Moroi SE. Cataract surgery in patients with nanophthalmos: results and complications. J Cataract Refract Surg. 2004;30(3):584\u0026ndash;90.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTailor R, Ng AT, Murthy S. Cataract surgery in patients with nanophthalmos. Ophthalmology. 2014;121(2):e11.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCarricondo PC, Andrade T, Prasov L, Ayres BM, Moroi SE. Nanophthalmos: A Review of the Clinical Spectrum and Genetics. J Ophthalmol. 2018;2018:2735465.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFaisal AA, Kamaruddin MI, Toda R, Kiuchi Y. Successful recovery from misdirection syndrome in nanophthalmic eyes by performing an anterior vitrectomy through the anterior chamber. Int Ophthalmol. 2019;39(2):347\u0026ndash;57.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-ophthalmology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"boph","sideBox":"Learn more about [BMC Ophthalmology](http://bmcophthalmol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/boph","title":"BMC Ophthalmology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Nanophthalmos (NO), Secondary angle-closure glaucoma; Penetrating canaloplasty (PCP), Anterior vitrectomy, Ciliary body cauterization, Minimally invasive glaucoma surgery (MIGS)","lastPublishedDoi":"10.21203/rs.3.rs-7381786/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7381786/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cb\u003eBackground\u003c/b\u003e\u003c/p\u003e\u003cp\u003eNanophthalmos (NO) is a rare congenital condition often associated with secondary angle-closure glaucoma. Due to structural abnormalities, nanophthalmic eyes are prone to serious postoperative complications such as uveal effusion, malignant glaucoma, and explosive suprachoroidal hemorrhage following filtering surgeries. Penetrating canaloplasty (PCP) is a modified version of canaloplasty (CP) and a minimally invasive glaucoma surgery (MIGS) that does not rely on a filtering bleb. It is not limited by angle anatomy and has broad indications, making it particularly suitable for angle-closure glaucoma. This report presents two cases treated with PCP combined with anterior vitrectomy and partial ciliary body cauterization, highlighting the potential therapeutic value of this surgical approach in eyes with complex anterior segment anatomy and strategies for managing postoperative complications.\u003c/p\u003e\u003cp\u003e\u003cb\u003eCase presentation\u003c/b\u003e\u003c/p\u003e\u003cp\u003eWe report two cases of NO with secondary angle-closure glaucoma, both of whom underwent bilateral penetrating canaloplasty combined with anterior vitrectomy and partial ciliary body cauterization. Postoperative follow-up durations were 3 and 7 months, respectively. Intraocular pressure (IOP) remained well controlled in both patients without the need for additional antiglaucoma medications. One case showed no significant postoperative complications, while the other developed choroidal detachment, which resolved well with conservative treatment.\u003c/p\u003e\u003cp\u003e\u003cb\u003eConclusions\u003c/b\u003e\u003c/p\u003e\u003cp\u003ePCP combined with anterior vitrectomy and partial ciliary body cauterization may be a feasible option for managing secondary angle-closure glaucoma in nanophthalmic eyes. It provides effective IOP control without blebs. The differing postoperative recoveries of the two patients prompt further reflection on individual anatomical variations and potential risk factors\u0026mdash;such as axial length and gender\u0026mdash;that may influence surgical outcomes. Emphasizes the importance of comprehensive preoperative evaluation and risk management.\u003c/p\u003e","manuscriptTitle":"Penetrating Canaloplasty Combined with Anterior Vitrectomy and Partial Ciliary Body Cauterization for Secondary Angle-Closure Glaucoma in Nanophthalmos: A Two-Case Report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-23 07:47:29","doi":"10.21203/rs.3.rs-7381786/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2025-09-26T18:35:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"317254201053130702418466479082416997082","date":"2025-09-17T08:50:05+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"289958135537136881399099983862537170479","date":"2025-09-15T07:10:30+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-15T06:51:12+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-08-19T09:57:22+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-17T22:43:01+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-17T22:42:22+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Ophthalmology","date":"2025-08-15T13:24:23+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-ophthalmology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"boph","sideBox":"Learn more about [BMC Ophthalmology](http://bmcophthalmol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/boph","title":"BMC Ophthalmology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"afe6b6a5-e7e9-4ced-9373-9c7de3666ace","owner":[],"postedDate":"September 23rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-09-23T07:47:29+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-23 07:47:29","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7381786","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7381786","identity":"rs-7381786","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}