Comparative study of efficacy and safety between nDSEK and DSEK for bullous keratopathy

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However, few studies have compared the clinical outcome between nDSEK (a modified version of the DSEK procedure known as non-Descemet stripping endothelial keratoplasty) and DSEK. This study aims to compare the potential efficacy and safety of nDSEK and DSEK in treating bullous keratopathy. Methods A retrospective comparative study included patients with bullous keratopathy underwent either nDSEK or DSEK between August 2017 and July 2022. These subjects were monitored for a period ranging from 6 to 36 months. The important factors such as best corrected visual acuity (BCVA), endothelial cell density (ECD), endothelial cell loss (ECL), and any complications that occurred during the follow-up period were recorded. Results A total of 52 eyes from 52 patients with bullous keratopathy were included. All subjects underwent either nDSEK (24 eyes) or DSEK (28 eyes). The mean BCVA (logMAR) showed significant improvement from the preoperative measurement of 1.69 ± 0.23 to 0.47 ± 0.22 in nDSEK eyes and from the preoperative 1.67 ± 0.19 to 0.36 ± 0.17 in DSEK eyes respectively at postoperative 12 months. However, there was no statistically significant difference in improvement of BCVA between the nDSEK and DSEK eyes (P = 0.263). The mean donor ECD decreased from the preoperative 2848 ± 108 cells/mm 2 to 1176 ± 269 cells/mm 2 (ECL 59%) in nDSEK eyes and from the preoperative 2905 ± 132 cells/mm 2 to 1235 ± 368 cells/mm 2 (ECL 57%) in DSEK eyes respectively at postoperative 12 months, with no significant difference between the nDSEK and DSEK eyes (P = 0.185). The occurrence of various complications such as graft dislocation (8.3% in nDSEK eyes vs 3.6% in DSEK eyes, P = 0.891), acute high introcular pressure (4.2% in nDSEK eyes vs 7.1% in DSEK eyes, P = 1), primary graft failure (8.3% in nDSEK eyes vs 7.1% in DSEK eyes, P = 1), graft rejection (8.3% in nDSEK eyes vs 3.6% in DSEK eyes, P = 0.891) did not differ significantly between the nDSEK and DSEK eyes. Conclusions nDSEK eliminated the descemetorrhexis step but yielded a comparable clinical outcome in terms of both effectiveness and safety when compared to DSEK for treating bullous keratopathy. Descemet stripping endothelial keratoplasty non-Descemet stripping endothelial keratoplasty bullous keratopathy Figures Figure 1 Figure 2 Backgroud Endothelial keratoplasty (EK) has greater advantages than penetrating keratoplasty (PK) for the treatment of bullous keratopathy as it offers faster visual recovery, fewer complications like graft rejection, and is now extensively employed in developed nations. Over the past two decades, EK has evolved significantly through the utilization of different techniques, such as Descemet stripping endothelial keratoplasty (DSEK), Descemet stripping automated endothelial keratoplasty (DSAEK), femtosecond laser-assisted DSEK (FS-DSEK), and Descemet membrane endothelial keratoplasty (DMEK). However, it has not been popularized in developing country like China, which can be attributed to factors like the high cost of instruments required for procedures like DSAEK and FS-DSEK. Additionally, DMEK poses challenges due to its difficult technique, such as a steep learning curve and limited applicability in patients with severe edematous stroma or aphakic eyes or those who have undergone previous vitrectomy. Other obstacles include the preparation of the donor Descemet membrane without any wastage, proper manipulation and adhesion of the delicate membrane while minimizing harm to the donor endothelium. Therefore, considering the constraints of limited resources, it remains reasonable to conduct DSEK as a viable therapy for bullous keratopathy. The standard DSEK procedure involves stripping off the Descemet membrane and transplanting the posterior lamellar graft. However, few studies have reported a modified version of the DSEK procedure known as non-Descemet stripping endothelial keratoplasty (nDSEK), where the procedure of stripping off the Descemet membrane is no longer required. Thus prior studies have demonstrated positive clinical outcomes for both nDSEK [ 1 , 2 ] and non-Descemet stripping endothelial keratoplasty in DSAEK [ 3 ]. However, few studies have compared the clinical outcomes between nDSEK and DSEK. Here, we present a comparative study on the potential efficacy and safety of nDSEK and DSEK in the treatment of bullous keratopathy. Methods This was a retrospective comparative study including a total of 52 eyes from 52 patients who had undergone nDSEK or DSEK for bullous keratopathy. This study was approved by the Medical Ethics Committee of the Nanning Aier Eye Hospital, China. This study was carried out in accordance with the principles of the Declaration of Helsinki, and all patients provided informed consent. All subjects were subjected to nDSEK (n = 24, including 2 eyes with PK history who avoided prior PK wound dehiscence possibly during operation [ 4 ]) or DSEK (n = 28, including 2 eyes affected with Fuchs’ endothelial dystrophy in which Descemet membrane stripping was recommended due to the pathological guttata potentially affecting the visual improvement [ 5 ]). All the surgeries were performed by Dr. Minghai Huang at the Nanning Aier Eye Hospital between August 2017 and July 2022. The inclusion criterion was the presence of vision impairment caused by bullous keratopathy. Individuals who had prominent corneal scars on their visual axis were excluded. Information related to demographics, visual acuity, corneal endothelial cell count, and postoperative complications were collected from the medical records. Preparation of donor lenticule The Donor corneas were prepared manually according to the technique described previously by Price et al [ 6 ]. A corneoscleral button obtained from a donor was preserved using the storage medium Eusol-C (Alchima, Padova, Italy) at a temperature of 4°C. The button was then placed onto an artificial anterior chamber and subjected to controlled air pressure through a sterile injection. A peripheral groove was subsequently made with a 350 µm blade to enable dissection across the cornea at a depth of 350 µm by a curved lamellar dissector. Finally, the donor tissue was punched out from posterior surface with a 7.75 mm or 8.0 mm trephine and the donor lenticule was subsequently implanted. Surgical procedure The surgery was carried out using either general anesthesia or retrobulbar block anesthesia with a 50% mixture of lidocaine (2%) and bupivacaine (0.5%). A 4.0-mm superior or temporal scleral tunnel incision was created according to the different eye conditions. The central epithelium of the cornea was removed to provide a clear view of the anterior chamber, then descemetorrhexis was performed using a reverse Sinsky hook during DSEK. With the aid of cohesive viscoelasticity, the Descemet membrane and endothelium were gently stripped from the central region and removed from the anterior chamber. In contrast to DSEK, descemetorrhexis was not performed in nDSEK. To avoid pupillary blockage, a routine procedure of peripheral iridectomy was routinely performed at six clock if the eyes had no previous peripheral iridectomy. Patients with endothelial decompensation caused by tube-endothelium contact were subjected to trimming off the shunt tube in eyes with controlled glaucoma. Peripheral anterior synechiolysis was performed to relieve secondary angle closure in eyes with anterior synechiae of the iris. A suture pullthrough technique was applied for donor insertion as described earlier by Hong et al [ 7 ]. An anchor single 10 − 0 nylon suture stitch was thereafter placed on the donor lenticule, the donor lenticule was then inserted into the anterior chamber by pulling the suture stitch, with the help of a Busin glide through a 4-mm incision. Finally, the main incision was closed with sutures after the procedure. The donor lenticule was then secured against the host cornea using nearly full intracameral sterile air tamponade. In eyes with severe cataract, we conducted nDSEK or DSEK along with phacoemulsification and implantation of an intraocular lens. For aphakic eyes, we used a sutureless scleral fixation technique or transscleral suture fixation to implant a foldable intraocular lens in the posterior chamber. If necessary, we also performed limited anterior vitrectomy simultaneously in cases where there was insufficient or no capsular support. The eyes with large iris defects underwent nDSEK or DSEK combined with pupilloplasty. Finally, all patients received a peribulbar injection of 2 mg dexamethasone. The patients were instructed to lie supine for 2 days after the surgery. All patients received topical 0.5% levofloxacin eye drops ( Santen Pharmaceutical Co., Ltd. Noto Plant) QID for two weeks. Additionally, they received tobramycin and dexamethasone eye ointment (Alcon-Couvreur SA, Puurs, Belgium) for 1 month. They were prescribed 1% Prednisolone Acetate Ophthalmic Suspension (Allergan Pharmaceuticals Ireland) QID for 1 month. Following this, the doses were gradually reduced over a period of 12 months. After 1 year topical steroids were switched to 0.1% fluorometholone eye drops (Santen Pharmaceutical Co.,Ltd.Noto Plant) to be used once daily. During follow-up visits, all the patients were examined using a slit lamp (Topcon Corporation, Tokyo, Japan) along with anterior segment optical coherence tomography ( AS-OCT, Heidelberg Engineering GmbH, Germany). The study assessed the uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and endothelial cell density (ECD) using different equipment at different time intervals (3 months, 6 months and 12 months postoperatively). The donor ECD was examined before surgery by EB-3000 XYZ, HAI Laboratories Inc., Lexington, MA, and after surgery by Tomey EM-4000, Tomey Co., Nagoya, Japan. For statistical analysis, decimal VA was converted into logarithm of minimal angle of resolution (logMAR), with counting fingers being 2.0 logMAR and hand movements being 2.3 logMAR [ 8 ]. The cases with primary graft failure in the eyes were excluded from the analysis of BCVA and ECD. Primary graft failure was defined as an attached donor lenticle without evidence of corneal clarity within two months after the surgery. The statistical analyses were conducted using IBM SPSS Statistics, version 22 (IBM Corp., Armonk, NY, USA). The values have been shown as mean ± standard deviation. Statistical analysis was conducted to compare demographic characteristics and baseline clinical data between the two groups, utilizing Student's t-test or Chi-square test. The changes in BCVA and ECD over time between the two groups were assessed using a general linear model repeated measures ANOVA analysis. Statistical significance was set at p < 0.05. Results Demographic characteristics and baseline clinical data of patients This study included a total of 52 eyes from 52 patients (nDSEK n = 24 eyes, DSEK n = 28 eyes), and the follow-up period ranged from 6 to 36 months, with a mean of 18 ± 9 months. The mean age of patients in the nDSEK group was 60.8 ± 15.7 years, ranging from 31 to 87 years. In the DSEK group, the mean age was 62.1 ± 15.2 years, ranging from 32 to 93 years. The proportion of females in the nDSEK group was 41.7%, while in the DSEK group it was 64.3% (Table 1 ). The frequent indications included endothelial decompensation after cataract surgery, such as pseudophakic ( 31 eyes, 59.6%; nDSEK n = 15; DSEK n = 16), aphakic bullous keratopathy (5 eyes 9.6%; nDSEK n = 3; DSEK = 2) as well as other less common etiologies, such as iridocorneal endothelial syndrome (8 eyes, 15.4%; nDSEK n = 3; DSEK n = 5), Fuchs’ endothelial dystrophy (2 eyes 3.8%; DSEK n = 2 ), corneal endotheliitis (3 eyes 5.7%; nDSEK n = 1; DSEK n = 2 ), unknown etiology (3 eyes, 5.7%; nDSEK n = 2; DSEK n = 1 ) as shown in Table 1 . The surgical history comprised a significant proportion of glaucoma surgery cases (15 eyes, accounting for 28.8% of the total), with the majority of these cases involving nDSEK (6 eyes) and DSEK (9 eyes). A smaller portion of the surgical history was attributed to ocular trauma cases (8 eyes, representing 15.4% of the total), including both nDSEK (5 eyes) and DSEK (3 eyes), (Table 1 ). Additionally, there were 2 cases (3.8%) related to a history of PK in which nDSEK was performed. There were no statistically significant differences found in the data related to age (P = 0.759), sex (P = 0.103), history of glaucoma surgery (P = 0.571) and ocular trauma (P = 0.533), indications (P = 0.404), preoperative BCVA (P = 0.830), and ECD (P = 0.102), (Table 1 ). Table 1 Demographic characteristics and baseline clinical data of patients nDSEK (n = 24) DSEK(n = 28) P value Age (years) 60.8 ± 15.7 62.1 ± 15.2 0.759 Female 10(41.7%) 18(64.3%) 0.103 Preoperative BCVA (LogMAR) 1.71 ± 0.26 1.73 ± 0.22 0.830 Donor ECD (cells/mm 2 ) 2857 ± 120 2914 ± 125 0.102 History of glaucoma surgery 6(25%) 9(32.1%) 0.571 History of ocular trauma 5(20.8%) 3(10.7%) 0.533 Indications 0.404 Decompensation after cataract surgery 18(75%) 18(64.3%) Other etiologies 6(25%) 10(35.7%) nDSEK = non-Descemet stripping endothelial keratoplasty; DSEK = Descemet stripping endothelial keratoplasty; BCVA = best corrected visual acuity; LogMAR = logarithm of minimal angle of resolution; ECD = endothelial cell density; decompensation after cataract surgery including pseudophakic (nDSEK n = 15; DSEK n = 16) and aphakic bullous keratopathy (nDSEK n = 3; DSEK = 2); other etiology including iridocorneal endothelial syndrome (nDSEK n = 3; DSEK n = 5),Fuchs’ endothelial dystrophy (DSEK n = 2 ), corneal endotheliitis (nDSEK n = 1; DSEK n = 2 ), unknown etiology (nDSEK n = 2; DSEK n = 1 ) General observation All patients experienced pain relief and felt comfortable with the disappeared corneal edema and bullae within 1 ~ 3 months after the successful surgery. There were no visible differences observed in the clear cornea when examined under a slit-lamp microscope between the eyes that underwent nDSEK and DSEK procedures. Additionally, the donor lenticule and recipient bed were securely attached. Figure 1 depicts representative photographs captured using a slit-lamp microscope and AS-OCT technology. Visual outcomes Data analysis on BCVA did not include 4 eyes that experienced primary graft failure (nDSEK n = 2;DSEK n = 2) and 3 eyes with significant visual impairments due to coexisting conditions (nDSEK n = 1, combined optic atrophy ; DSEK n = 2, combined optic atrophy and macular degeneration). The visual outcomes showed gradual improvement in the months following surgery, steadily progressing until the 6-month mark for the majority of nDSEK and DSEK eyes. However, this progress was not observed in cases where patients also had serious macular degeneration or optic atrophy. The mean postoperative BCVA (logMAR) significantly improved from the preoperative 1.69 ± 0.23 to 0.59 ± 0.18 at postoperative 3 months, 0.45 ± 0.20 at postoperative 6 months, 0.47 ± 0.22 at postoperative 12 months respectively in nDSEK eyes. In addition, the mean postoperative BCVA (logMAR) improved from the preoperative 1.67 ± 0.19 to 0.53 ± 0.22 at postoperative 3 months, 0.38 ± 0.18 at postoperative 6 months, 0.36 ± 0.17 at postoperative 12 months respectively in DSEK eyes. Despite this, no statistically significant differences were found between the nDSEK and DSEK eyes in terms of statistical significance at the corresponding time intervals (P = 0.263; Table 2 ; Fig. 2 ). Table 2 Changes in BCVA and ECD at different time points after the surgery nDSEK n DSEK n P value Changes in BCVA 0.263 Preoperative BCVA (LogMAR) 1.69 ± 0.23 21 1.67 ± 0.19 24 BCVA at 3 months (LogMAR) 0.59 ± 0.18 21 0.53 ± 0.22 24 BCVA at 6 months (LogMAR) 0.45 ± 0.20 21 0.38 ± 0.18 24 BCVA at 12 months (LogMAR) 0.47 ± 0.22 17 0.36 ± 0.17 20 Changes in ECD 0.185 Preoperative ECD (cells/mm 2 ) 2848 ± 108 22 2905 ± 132 26 ECD at 3 months(cells/mm 2 )(ECL%) 1612 ± 131(43%) 22 1725 ± 189 (41%) 26 ECD at 6 months(cells/mm 2 )(ECL%) 1382 ± 166(52%) 22 1475 ± 296 (49%) 26 ECD at 12 months(cells/mm 2 )(ECL%) 1176 ± 269 (59%) 18 1235 ± 368(57%) 22 nDSEK = non-Descemet stripping endothelial keratoplasty; DSEK = Descemet stripping endothelial keratoplasty; BCVA = best-corrected visual acuity; LogMAR = logarithm of minimal angle of resolution; ECD = endothelial cell density; ECL = endothelial cell loss. Data for analysis on the preoperative BCVA excluded 4 eyes resulting from the primary graft failure (nDSEK n = 2;DSEK n = 2) and 3 eyes with serious visual impairing optic atrophy or affected with macular degeneration co-morbidity (nDSEK n = 1;DSEK n = 2), Preoperative ECD excluded 4 eyes resulting from the primary graft failure (nDSEK n = 2;DSEK n = 2) Endothelial cell density and endothelial cell loss (ECL) The Cases with primary graft failure (nDSEK n = 2; DSEK n = 2) were omitted from the analysis of donor ECD data. After the surgery, the mean donor ECD decreased from the preoperative 2848 ± 108 cells/mm 2 to 1612 ± 131 cells/mm 2 (ECL 43%)at postoperative 3 months postoperative,1382 ± 166 cells/mm 2 (ECL 52%)at 6 months postoperative and 1176 ± 269 cells/mm 2 (ECL 59%) at 12 months postoperative respectively in nDSEK eyes. Similarly, in DSEK eyes the mean donor ECD decreased from the preoperative 2905 ± 132 cells/mm 2 to 1725 ± 189 cells/mm 2 ( ECL 41%) at 3 months postoperative, 1475 ± 296 (ECL 49%) cells/mm 2 at 6 months postoperative and 1235 ± 368 cells/mm 2 (ECL 57%) at 12 months postoperative respectively. However, there were no statistically significant differences found between the nDSEK and DSEK eyes at the same time points ( P = 0.185; Table 2 ; Fig. 2 ). Complications Graft dislocation occurred in two eyes (8.3%) after nDSEK and one eye (3.6%) after DSEK respectively on the postoperative days 1 to day 2. However, successful rebubbling was conducted in all these instances. The graft dislocation rates did not show any significant differences between nDSEK and DSEK eyes, ( P = 0.891; Table 3 ). Acute high intraocular pressure occurred in one eye (4.2%) after nDSEK and two eyes (7.1%) after DSEK respectively even routinely had Peripheral iridectomy, This issue was effectively addressed by either removing excess air that caused blockage in the pupil or by performing the angle reformation due to secondary angle closure from air migration posterior to the iris between the postoperative days 0 and day 1. There were no statistically significant differences found in the rate of acute high intraocular pressure between the nDSEK and DSEK eyes (P = 1; Table 3 ). Two eyes (8.3%) experienced primary graft failure following nDSEK, while two eyes (7.1%) experienced it after DSEK. Within six months, all these eyes underwent regrafting using fresh endothelial donor tissue through either nDSEK or DSEK, except for one DSEK eye which required penetrating keratoplasty at 12 months after the initial surgery. However, there were no statistically significant differences found in the primary graft failure rates between the nDSEK and DSEK eyes (P = 1; Table 3 ). Graft rejection was observed in 8.3% of eyes following nDSEK, while only 3.6% of eyes experienced rejection after DSEK. However, the study found no significant differences in the occurrence of endothelial graft rejection between the nDSEK and DSEK eyes ( P = 0.891; Table 3 ). All these rejection cases were managed with frequent topical prednisolone acetate eye drops and subconjunctival injections of dexamethasone. Despite positive response in one nDSEK eye, the other cases eventually experienced secondary graft failure. However, no serious complications such as suprachoroidal hemorrhage, postoperative endophthalmitis, and interface infection were observed in either nDSEK or DSEK eyes during the follow-up period. Table 3 Complications observed after the surgery nDSEK (n = 24) DSEK (n = 28) P value Graft dislocation 2(8.3%) 1(3.6%) 0.891 Acute high introcular pressure 1(4.2%) 2(7.1%) 1 Primary graft failure 2(8.3%) 2(7.1%) 1 Graft rejection 2(8.3%) 1(3.6%) 0.891 nDSEK, non-Descemet stripping endothelial keratoplasty; DSEK, Descemet stripping endothelial keratoplasty. Discussion Visual outcomes In the present study, postoperative BCVA (logMAR) in both nDSEK eyes ( 0.59 ± 0.18 at postoperative 3 months, 0.45 ± 0.20 at postoperative 6 months, 0.47 ± 0.22 at postoperative 12 months respectively) and DSEK eyes (0.53 ± 0.22 at postoperative 3 months, 0.38 ± 0.18 at postoperative 6 months, 0.36 ± 0.17 at postoperative 12 months respectively) showed improvement, with the exception of cases where there were other concomitant pathologies such as serious macular degeneration and optic atrophy. The improvements in BCVA were significant and comparable between the two groups. The postoperative visual improvement observed in this study was comparable with that reported in other previous studies. For instance, a study by Price group [ 9 ] found that after DSEK, the mean BCVA (logMAR) was 0.47 ± 0.34 at the 3 months examination, and 0.39 ± 0.34 at the 6 months examination. These results demonstrate a significant improvement compared to the initial BCVA of 0.66 ± 0.54 before the surgery. In Zhang’s study [ 2 ], results demonstrated that after nDSEK, the mean BCVA (logMAR) improved from 1.70 preoperatively to 0.54 at 3 months, 0.46 at 6 months, and 0.37 at 1 year after the surgery, respectively. Moreover, in a comparative study by Mohamed et al. [ 10 ], the mean BCVA (logMAR) at 6 months postoperatively in the DSEK and nDSEK eyes were found to be 0.18 and 0.44, respectively, with no significant difference observed between them. A recent study conducted by Omoto et al [ 11 ] compared the long-term outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK) and non-Descemet stripping automated endothelial keratoplasty (nDSAEK). The study found that the mean preoperative BCVA (logMAR) of nDSAEK and DSAEK eyes were 1.08 and 1.11, respectively. However, these values significantly improved over time to 0.238 and 0.190, 0.126 and 0.157, and 0.097 and 0.070 at 1, 3, and 5 years, respectively. There were no statistically significant differences between nDSAEK and DSAEK in BCVA improvement, suggesting that stripping of the recipient Descemet membrane may not be necessary and has minimal influence on long-term results. We concluded that there were multiple factors that contributed to the lower level of visual improvement in our study compared to the previous studies. For example, the mean preoperative BCVA was very poor, primarily caused by significant corneal swelling due to the long waiting time for the surgery. Interestingly, our findings contradicted the previous reports that stated Fuchs' endothelial dystrophy as the most common indication for keratoplasty1 [ 12 , 13 ]. Instead, our study revealed a higher prevalence of pseudophakic bullous keratopathy/aphakic bullous keratopathy. Additionally, other etiologies like iridocorneal endothelial syndrome were not less common, and a significant number of cases had a history of glaucoma surgery. Moreover, some of the cases in our study had a history of previous cataract-vitreous-retinal surgery due to ocular trauma and had complications like severe corneal edema, abnormal anterior segment such as anterior synechia, aphakia, iris defect, and concomitant pathology such as serious macular degeneration as well as optic atrophy. These complications also affected the clinical results such as postoperative visual improvement. However, we found in the present study that the visual improvement was similar for both nDSEK and DSEK eyes when performed by the same surgeon. We found that nDSEK can potentially provide similar visual improvement as classic DSEK, except in cases of Fuchs' endothelial dystrophy and obvious Descemet membrane abnormalities. The advantage of nDSEK is that it eliminates the need for descemetorrhexis, and interestingly, we observed that preserving the recipient's Descemet membrane does not impact visual recovery. Endothelial cell density and endothelial cell loss According to our study, there was a significant decrease in donor endothelial cell density (ECD) in both nDSEK and DSEK eyes at various postoperative time points. Specifically, in nDSEK eyes, the ECD decreased from the preoperative 2848 ± 108 cells/mm 2 to 1612 ± 131 cells/mm 2 (ECL 43%) at 3 months postoperative, 1382 ± 166 cells/mm 2 (ECL 52%) at 6 months postoperative and 1176 ± 269 cells/mm 2 (ECL 59%) at 12 months postoperative. Similarly, in DSEK eyes, the ECD decreased from the preoperative 2905 ± 132 cells/mm 2 to 1752 ± 189 cells/mm 2 (ECL 41%) at 3 months postoperative, 1475 ± 296 cells/mm 2 (ECL 49%) at 6 months postoperative and 1235 ± 368 cells/mm 2 (ECL57%) at 12 months postoperative. However, there were no statistically significant differences in ECD between nDSEK and DSEK eyes at the same time point. Interestingly, the ECL in both nDSEK and DSEK eyes in the present study was found to be higher than those reported in the previous studies. For instance, in Price’ study on DSEK, the ECL was 34% at 6 months, 36% at 12 months,41% at 24 months [ 14 ]. Moreover, in Mohamed’s study, the ECL in the DSEK and nDSEK eyes was 28.1%±17.1% and 23.6%±8.3%, respectively [ 10 ]. We infer that the increased loss of endothelial cells in our recent study may be due to various factors following nDSEK and DSEK procedures. First, eye conditions such as prior cataract-vitreous-retinal surgery (ocular trauma history ), glaucoma drainage implantation, complicated eye with severe corneal edema, abnormal anterior segment such as anterior synechia, aphakia, and iris defect, can make endothelial keratoplasty more challenging for these complex cases. Second, factors related to the surgery itself, such as incision size, donor tissue preparation, as well as graft delivery devices, rebubbling for donor tissue dislocation and the learning curve of EK for the surgeon [ 14 , 15 , 16 , 17 ] also associated with postoperative corneal endothelial loss. All of these factors can affect the ECL and lead to higher ECL as observed in our present study. Complications The most common complication encountered in endothelial keratoplasty is graft dislocation, which occurs at a wide range of rates, from 0–80%, with an average dislocation rate of 14.5% [ 18 ]. Several factors, such as the surgeon's experience, viscoelastic in the graft interface, geometric mismatch between donor and recipient curvatures that cause a portion of the donor to arc away from the recipient, residual strands of either stroma or Descemet membrane that prevent tight apposition of the donor against the recipient all can contribute to the influence on the surgery [ 17 , 19 ]. In the present study, graft dislocation occurred in 8.3% nDSEK eyes and 3.6% DSEK eyes, with no significant variation between the nDSEK and DSEK groups. Our study seems to indicate that the preservation of the recipient's Descemet membrane does not impact the attachment of the donor lenticule to the recipient bed. However, this factor could potentially influence the rate of graft dislocation. Acute high intraocular pressure was observed in 1 eye (4.2%) after nDSEK and 2 eyes (7.1%) after DSEK, in spite of the routine peripheral iridectomy performed. However, there were no significant statistical differences between the occurrence of this complication in nDSEK and DSEK eyes. The rate of acute high intraocular pressure was relatively lower, as compared to the 10.5% reported in the study conducted by Daubert et al [ 17 ] but higher than 2.8% reported by study of Basaket al [ 20 ]. The higher rate of acute high intraocular pressure in our present study could be associated with the use of a full intracameral air tamponade to obtain firm attachment of the donor at the end of surgery without releasing the air postoperatively. This method may result in elevated intraocular pressure due to air-induced pupillary block and occlusion of iridotomy not only in nDSEK but also in DSEK eyes. The literature shows a broad range of primary graft failure rates, ranging from 0–29%, with an average rate of 5% [ 18 ]. In the present study, there were no statistically significant differences observed in the occurrence of primary graft failure between nDSEK and DSEK eyes, as two eyes (8.3%) with primary graft failure were observed in nDSEK eyes, while two eyes (7.1%) experienced primary graft failure in DSEK eyes. The rate of primary graft failure in our study exceeded the percentages reported by Price, which were 5% and 6% [ 6 , 9 ]. Several key factors contributing to complications during anterior segment surgery include the surgeon's level of expertise in performing EK, the presence of surgical eyes with complicated abnormal anterior segment, poor quality of donor tissue, and donor tissue preparation [ 6 , 21 ]. In our study, the higher rate of primary graft failure could be attributed to the intricacy of the surgical procedure and the challenging learning process of EK for surgeons. We found that graft rejection occurred in two eyes (8.3%) after nDSEK in comparison to one eye (3.6%) after DSEK. However, no significant statistical difference in graft rejection rates was observed. The graft rejection rate (8.3%) after nDSEK was found to be higher in comparison to Chaurasia’ report [ 4 ] of 4.3% after nDSEK and Zhang’ report [ 2 ] of 3.1% after nDSEK. The factors that increase the risk of corneal rejection include host bed vascularity due to longer corneal edema in bullous keratopathy eye, clinical history of glaucoma, previous surgeries such as glaucoma surgery or anterior segment surgery, anterior iris synechiae, vitreous adhesion, re-grafts, multiple surgeries performed simultaneously [ 22 ]. Moreover, different postoperative steroid management and the duration of follow-up posed challenges in directly comparing rejection rates across different studies. Thus, the rejection rate in various studies may vary due to the impact of these aforementioned factors. Limitations There are several limitations of the current study, such as retrospective study, small sample size, heterogeneity in terms of indication for transplant and ocular co-morbidities, and short duration of follow-up. Future well-designed randomized controlled trial with large sample sizes and an extensive follow-up duration are needed to verify the results of this study. Conclusions In conclusion, our study found that nDSEK effectively eliminated the need for descemetorrhexis in treating bullous keratopathy. Despite this modification, the clinical effectiveness and safety of nDSEK remained comparable to traditional DSEK. Therefore, we consider nDSEK to be a valuable option for managing bullous keratopathy, particularly in situations where resources are limited, excluding cases of Fuchs' endothelial dystrophy and significant abnormalities in the Descemet membrane. Declarations Ethics approval and consent to participate This study was approved by the Medical Ethics Committee of the Nanning Aier Eye Hospital, China. This study was carried out in accordance with the principles of the Declaration of Helsinki, and all patients provided informed consent. All methods were carried out in accordance with relevant guidelines and regulations. Consent for publication Informed consent was obtained from all subjects for publication of identifying Competing interests The authors have no conflicts of interest to disclose. Funding This study was supported by the Self-funded Scientific Research Project of Guangxi Zhuang Autonomous Region Health Commission (grant number:Z20201374). Author Contribution The study was conceptualized and designed by M.H. ; Collection of data (G.Y., T.H., Z.W.); Analysis of data (J.T., Z.Z., D.W.); Preparation of manuscript (M.H.). All authors reviewed and approved the final manuscript. Acknowledgments The author would like to thank all the reviewers who participated in the review and MJEditor ( www.mjeditor.com ) for its linguistic assistance during the preparation of this manuscript. Availability of data and materials The data presented in this study are available on request from the corresponding author. References Price FW Jr, Price MO. Endothelial Keratoplasty to Restore Clarity to a Failed Penetrating Graft. Cornea. 2006;25(8):895–9. Zhang T, Li SW, Chen TH, He JL, Kang YW, Lyu FQ, Ning JH, Liu C. Clinical results of non-Descemet stripping endothelial keratoplasty. Int J Ophthalmol. 2017;10(2):223–7. Wajima H, Hayashi T, Kobayashi A, Nishino T, Mori N, Yokogawa H, Yamagami S. Sugiyama K.Graft rejection episodes after keratoplasty in. Japanese eyes Sci Rep. 2023;13(1):2635. Chaurasia S, Ramappa M, Sangwan VS. Clinical outcomes of nonDescemet stripping automated endothelial keratoplasty. Int Ophthalmol. 2012;32(6):571–5. Price MO, Price FW Jr. Endothelial keratoplasty—a review. Clin Exp Ophthalmol. 2010;38(2):128–40. Price MO, Price FW Jr.. Descemet’s Stripping with Endothelial Keratoplasty Comparative Outcomes with Microkeratome-Dissected and Manually Dissected Donor Tissue. Ophthalmology. 2006;113(11):1936–42. Hong Y, Peng RM, Wang M, Qu HQ, Hong J. Suture pull-through insertion techniques for Descemet stripping automated endothelial keratoplasty in Chinese phakic eyes: outcomes and complications. PLoS ONE. 2013;23(4):e61929. Lange C, Feltgen N, Junker B, Schulze-Bonsel K, Bach M. Resolving the clinical acuity categories hand motion and counting fingers using the Freiburg Visual Acuity Test (FrACT). Graefes Arch Clin Exp Ophthalmol. 2009;247:137–42. Price FW Jr. Price MO.Descemet’s Stripping With Endothelial Keratoplasty in 50 Eyes: A Refractive Neutral Corneal Transplant. Refract Surg. 2005;21:339–45. Mohamed A, Ks AR, Chaurasia S, Ramappa M. Outcomes of endothelial keratoplasty in pseudophakic corneal oedema: with or without Descemet’s membrane stripping. Br J Ophthalmol. 2016;100(6):754–6. Omoto T, Toyono T, Inoue T, Shirakawa R, Yoshida J, Miyai T, Yamagami S, Usui T. Comparison of 5-Year Clinical Results of Descemet and Non-Descemet Stripping Automated Endothelial. Cornea. 2020;39(5):573–7. Terry MA, Shamie N, Chen ES, Phillips PM, Shah AK, Hoar KL, Friend DJ. Endothelial keratoplasty for Fuchs' dystrophy with cataract: complications and clinical results with the new triple procedure. Ophthalmology. 2009;116(4):631–9. Dobbins KR, Price FW Jr, Whitson WE. Trends in the indications for penetrating keratoplasty in the Midwestern United States.Cornea. 2000;19(6):813–6. Price MO, Price FW Jr. Endothelial cell loss after Descemet stripping with endothelial keratoplasty: influencing factors and 2-year trend. Ophthalmology. 2008;115:857–65. Patel SV. Graft Survival and Endothelial Outcomes in the New Era of Endothelial Keratoplasty. Exp Eye Res. 2012;95(1):40–7. Fajgenbaum MA, Hollick EJ. Descemet Stripping Endothelial Keratoplasty in Iridocorneal Endothelial Syndrome: Postoperative Complications and Long-Term Outcomes. Cornea. 2015;34:1252–8. Daubert J, O'Brien TP, Adler E, Spierer O. Outcomes of complex Descemet Stripping Endothelial Keratoplasty performed by cornea fellows.BMC Ophthalmol. 2018, 30;18(1):281. Lee WB, Jacobs DS, Musch DC, Kaufman SC, Reinhart WJ, Shtein RM. Descemet’s Stripping Endothelial Keratoplasty: Safety and Outcomes A Report by the American Academy of Ophthalmology. Ophthalmology. 2009;116(9):1818–30. Price FW Jr, Price MO. A Nonsurgical Treatment for Donor Dislocation After Descemet Stripping Endothelial Keratoplasty (DSEK).Cornea. 2006;25(8):991. Basak SK, Basak S. Complications and management in Descemet's stripping endothelial keratoplasty: Analysis of consecutive 430 cases. Indian J Ophthalmol. 2014;62(2):209–18. Muijzer MB, van Luijk CM, van den Bogaerdt AJ, Kruit PJ, Groeneveld-van Beek E, Melles GRJ, Wisse RPL. Prospective evaluation of clinical outcomes between pre-cut corneal grafts prepared using a manual or automated technique: with one-year follow-up. Acta Ophthalmol. 2019;97(7):714–20. Di Zazzo A, Kheirkhah A, Abud TB, Goyal S, Dana R. Management of High-risk Corneal Transplantation. Surv Ophthalmol. 2017;62(6):816–27. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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-3886955","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":268524564,"identity":"4066737a-a6c3-4e74-b4e2-e7203fadcd76","order_by":0,"name":"Minghai Huang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABA0lEQVRIiWNgGAWjYBACAwglAUYHPlTYyLGxtx8gXsvBGWfSjPl4ziQQowWii5m37XDiPAkHAzwaGBjMJZKfPfyaY5EnH9388DBQS3qbBEMCw4+KbTi1WM5IMzeW3SZRbHjnmMHBOefSc9ukGw8w9py5jdthNxLMpCW3SSRunJFgcOBNmXVum8yBBGbGNnxa0r9BtaR/OMDDxpzOJpFgQEBLjpnkR6CW+RI5Bgd52pwTCGs586ZMmhGoZYNETgEokA3bgIF8EK9fjqdvk/y5rS5x/oz0zR+AUSkv395+8MGPCtxaQICZB6T3AJLIAewKEYDxB5CQbyCkbBSMglEwCkYsAADvH2CHnvhDbQAAAABJRU5ErkJggg==","orcid":"","institution":"Nanning Aier Eye Hospital","correspondingAuthor":true,"prefix":"","firstName":"Minghai","middleName":"","lastName":"Huang","suffix":""},{"id":268524565,"identity":"dc5fd985-89ef-49f3-9879-919280dba044","order_by":1,"name":"Guina Yin","email":"","orcid":"","institution":"Nanning Aier Eye Hospital","correspondingAuthor":false,"prefix":"","firstName":"Guina","middleName":"","lastName":"Yin","suffix":""},{"id":268524568,"identity":"7021d5d4-48f5-4a19-ac5e-13d035064a85","order_by":2,"name":"Thuthuy Hoang","email":"","orcid":"","institution":"Nanning Aier Eye Hospital","correspondingAuthor":false,"prefix":"","firstName":"Thuthuy","middleName":"","lastName":"Hoang","suffix":""},{"id":268524569,"identity":"e33b35e5-653d-43cd-88ff-ceaa880916bc","order_by":3,"name":"Zhifeng Wu","email":"","orcid":"","institution":"Nanning Aier Eye Hospital","correspondingAuthor":false,"prefix":"","firstName":"Zhifeng","middleName":"","lastName":"Wu","suffix":""},{"id":268524570,"identity":"233f3dd4-de39-4c5f-ac99-ec1ff845b6e6","order_by":4,"name":"Jian Teng","email":"","orcid":"","institution":"Nanning Aier Eye Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jian","middleName":"","lastName":"Teng","suffix":""},{"id":268524571,"identity":"d0fb28e9-27d0-4ccc-8be1-ecfd9b0f9f55","order_by":5,"name":"Yanqing Liang","email":"","orcid":"","institution":"Nanning Aier Eye Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yanqing","middleName":"","lastName":"Liang","suffix":""},{"id":268524572,"identity":"9afc98a0-2617-4434-8d28-4260588c14c7","order_by":6,"name":"Zhuoyuan Zhang","email":"","orcid":"","institution":"Nanning Aier Eye Hospital","correspondingAuthor":false,"prefix":"","firstName":"Zhuoyuan","middleName":"","lastName":"Zhang","suffix":""},{"id":268524573,"identity":"e3dc21ad-6a9f-4ae8-8f8c-a2c74cc72939","order_by":7,"name":"Dongmei Wei","email":"","orcid":"","institution":"Nanning Aier Eye Hospital","correspondingAuthor":false,"prefix":"","firstName":"Dongmei","middleName":"","lastName":"Wei","suffix":""}],"badges":[],"createdAt":"2024-01-22 04:59:39","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3886955/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3886955/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":50117071,"identity":"f05c491e-d201-494c-ba6b-cca60f9c4d50","added_by":"auto","created_at":"2024-01-24 18:54:27","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":623781,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative slit-lamp microscope and AS-OCT photographs after completion of successful surgery. The cornea appeared transparent with no visible differences between the nDSEK (A) and DSEK (B) eyes (when examined using a slit-lamp. top), donor lenticule adhered to recipient bed well (AS-OCT, bottom); nDSEK, non-Descemet stripping endothelial keratoplasty; DSEK, Descemet stripping endothelial keratoplasty.\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-3886955/v1/4324d5770f2ec81ba8b5c563.png"},{"id":50117949,"identity":"63b4be29-6b83-4195-80e2-b2613e49ae3d","added_by":"auto","created_at":"2024-01-24 19:02:27","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":146218,"visible":true,"origin":"","legend":"\u003cp\u003eThe comparison of BCVA and ECD after surgery shows variations between nDSEK and DSEK eyes at different time intervals. BCVA was found to be improved and ECD decreased with time, but there were no statistically significant differences observed for BCVA (P=0.263) and ECD ( P=0.185) between nDSEK and DSEK eyes at the same time point.\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-3886955/v1/0cecec91ba8fe73a8c4c0fa3.png"},{"id":64439980,"identity":"16e53404-21cd-4fcd-a677-7c7cf497ad38","added_by":"auto","created_at":"2024-09-13 08:02:07","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1775604,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3886955/v1/9175c304-f051-47d6-998a-29012cfb5c6c.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comparative study of efficacy and safety between nDSEK and DSEK for bullous keratopathy","fulltext":[{"header":"Backgroud","content":"\u003cp\u003eEndothelial keratoplasty (EK) has greater advantages than penetrating keratoplasty (PK) for the treatment of bullous keratopathy as it offers faster visual recovery, fewer complications like graft rejection, and is now extensively employed in developed nations. Over the past two decades, EK has evolved significantly through the utilization of different techniques, such as Descemet stripping endothelial keratoplasty (DSEK), Descemet stripping automated endothelial keratoplasty (DSAEK), femtosecond laser-assisted DSEK (FS-DSEK), and Descemet membrane endothelial keratoplasty (DMEK). However, it has not been popularized in developing country like China, which can be attributed to factors like the high cost of instruments required for procedures like DSAEK and FS-DSEK. Additionally, DMEK poses challenges due to its difficult technique, such as a steep learning curve and limited applicability in patients with severe edematous stroma or aphakic eyes or those who have undergone previous vitrectomy. Other obstacles include the preparation of the donor Descemet membrane without any wastage, proper manipulation and adhesion of the delicate membrane while minimizing harm to the donor endothelium. Therefore, considering the constraints of limited resources, it remains reasonable to conduct DSEK as a viable therapy for bullous keratopathy.\u003c/p\u003e \u003cp\u003eThe standard DSEK procedure involves stripping off the Descemet membrane and transplanting the posterior lamellar graft. However, few studies have reported a modified version of the DSEK procedure known as non-Descemet stripping endothelial keratoplasty (nDSEK), where the procedure of stripping off the Descemet membrane is no longer required. Thus prior studies have demonstrated positive clinical outcomes for both nDSEK [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] and non-Descemet stripping endothelial keratoplasty in DSAEK [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eHowever, few studies have compared the clinical outcomes between nDSEK and DSEK. Here, we present a comparative study on the potential efficacy and safety of nDSEK and DSEK in the treatment of bullous keratopathy.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eThis was a retrospective comparative study including a total of 52 eyes from 52 patients who had undergone nDSEK or DSEK for bullous keratopathy. This study was approved by the Medical Ethics Committee of the Nanning Aier Eye Hospital, China. This study was carried out in accordance with the principles of the Declaration of Helsinki, and all patients provided informed consent. All subjects were subjected to nDSEK (n\u0026thinsp;=\u0026thinsp;24, including 2 eyes with PK history who avoided prior PK wound dehiscence possibly during operation [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]) or DSEK (n\u0026thinsp;=\u0026thinsp;28, including 2 eyes affected with Fuchs\u0026rsquo; endothelial dystrophy in which Descemet membrane stripping was recommended due to the pathological guttata potentially affecting the visual improvement [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]). All the surgeries were performed by Dr. Minghai Huang at the Nanning Aier Eye Hospital between August 2017 and July 2022. The inclusion criterion was the presence of vision impairment caused by bullous keratopathy. Individuals who had prominent corneal scars on their visual axis were excluded. Information related to demographics, visual acuity, corneal endothelial cell count, and postoperative complications were collected from the medical records.\u003c/p\u003e \u003cp\u003ePreparation of donor lenticule\u003c/p\u003e \u003cp\u003eThe Donor corneas were prepared manually according to the technique described previously by Price et al [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. A corneoscleral button obtained from a donor was preserved using the storage medium Eusol-C (Alchima, Padova, Italy) at a temperature of 4\u0026deg;C. The button was then placed onto an artificial anterior chamber and subjected to controlled air pressure through a sterile injection. A peripheral groove was subsequently made with a 350 \u0026micro;m blade to enable dissection across the cornea at a depth of 350 \u0026micro;m by a curved lamellar dissector. Finally, the donor tissue was punched out from posterior surface with a 7.75 mm or 8.0 mm trephine and the donor lenticule was subsequently implanted.\u003c/p\u003e \u003cp\u003eSurgical procedure\u003c/p\u003e \u003cp\u003eThe surgery was carried out using either general anesthesia or retrobulbar block anesthesia with a 50% mixture of lidocaine (2%) and bupivacaine (0.5%). A 4.0-mm superior or temporal scleral tunnel incision was created according to the different eye conditions. The central epithelium of the cornea was removed to provide a clear view of the anterior chamber, then descemetorrhexis was performed using a reverse Sinsky hook during DSEK. With the aid of cohesive viscoelasticity, the Descemet membrane and endothelium were gently stripped from the central region and removed from the anterior chamber. In contrast to DSEK, descemetorrhexis was not performed in nDSEK. To avoid pupillary blockage, a routine procedure of peripheral iridectomy was routinely performed at six clock if the eyes had no previous peripheral iridectomy. Patients with endothelial decompensation caused by tube-endothelium contact were subjected to trimming off the shunt tube in eyes with controlled glaucoma. Peripheral anterior synechiolysis was performed to relieve secondary angle closure in eyes with anterior synechiae of the iris. A suture pullthrough technique was applied for donor insertion as described earlier by Hong et al [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. An anchor single 10\u0026thinsp;\u0026minus;\u0026thinsp;0 nylon suture stitch was thereafter placed on the donor lenticule, the donor lenticule was then inserted into the anterior chamber by pulling the suture stitch, with the help of a Busin glide through a 4-mm incision. Finally, the main incision was closed with sutures after the procedure. The donor lenticule was then secured against the host cornea using nearly full intracameral sterile air tamponade. In eyes with severe cataract, we conducted nDSEK or DSEK along with phacoemulsification and implantation of an intraocular lens. For aphakic eyes, we used a sutureless scleral fixation technique or transscleral suture fixation to implant a foldable intraocular lens in the posterior chamber. If necessary, we also performed limited anterior vitrectomy simultaneously in cases where there was insufficient or no capsular support. The eyes with large iris defects underwent nDSEK or DSEK combined with pupilloplasty. Finally, all patients received a peribulbar injection of 2 mg dexamethasone. The patients were instructed to lie supine for 2 days after the surgery. All patients received topical 0.5% levofloxacin eye drops ( Santen Pharmaceutical Co., Ltd. Noto Plant) QID for two weeks. Additionally, they received tobramycin and dexamethasone eye ointment (Alcon-Couvreur SA, Puurs, Belgium) for 1 month. They were prescribed 1% Prednisolone Acetate Ophthalmic Suspension (Allergan Pharmaceuticals Ireland) QID for 1 month. Following this, the doses were gradually reduced over a period of 12 months. After 1 year topical steroids were switched to 0.1% fluorometholone eye drops (Santen Pharmaceutical Co.,Ltd.Noto Plant) to be used once daily.\u003c/p\u003e \u003cp\u003eDuring follow-up visits, all the patients were examined using a slit lamp (Topcon Corporation, Tokyo, Japan) along with anterior segment optical coherence tomography ( AS-OCT, Heidelberg Engineering GmbH, Germany). The study assessed the uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and endothelial cell density (ECD) using different equipment at different time intervals (3 months, 6 months and 12 months postoperatively). The donor ECD was examined before surgery by EB-3000 XYZ, HAI Laboratories Inc., Lexington, MA, and after surgery by Tomey EM-4000, Tomey Co., Nagoya, Japan. For statistical analysis, decimal VA was converted into logarithm of minimal angle of resolution (logMAR), with counting fingers being 2.0 logMAR and hand movements being 2.3 logMAR [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. The cases with primary graft failure in the eyes were excluded from the analysis of BCVA and ECD. Primary graft failure was defined as an attached donor lenticle without evidence of corneal clarity within two months after the surgery.\u003c/p\u003e \u003cp\u003eThe statistical analyses were conducted using IBM SPSS Statistics, version 22 (IBM Corp., Armonk, NY, USA). The values have been shown as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation. Statistical analysis was conducted to compare demographic characteristics and baseline clinical data between the two groups, utilizing Student's t-test or Chi-square test. The changes in BCVA and ECD over time between the two groups were assessed using a general linear model repeated measures ANOVA analysis. Statistical significance was set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eDemographic characteristics and baseline clinical data of patients\u003c/p\u003e\n\u003cp\u003eThis study included a total of 52 eyes from 52 patients (nDSEK n\u0026thinsp;=\u0026thinsp;24 eyes, DSEK n\u0026thinsp;=\u0026thinsp;28 eyes), and the follow-up period ranged from 6 to 36 months, with a mean of 18\u0026thinsp;\u0026plusmn;\u0026thinsp;9 months. The mean age of patients in the nDSEK group was 60.8\u0026thinsp;\u0026plusmn;\u0026thinsp;15.7 years, ranging from 31 to 87 years. In the DSEK group, the mean age was 62.1\u0026thinsp;\u0026plusmn;\u0026thinsp;15.2 years, ranging from 32 to 93 years. The proportion of females in the nDSEK group was 41.7%, while in the DSEK group it was 64.3% (Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). The frequent indications included endothelial decompensation after cataract surgery, such as pseudophakic ( 31 eyes, 59.6%; nDSEK n\u0026thinsp;=\u0026thinsp;15; DSEK n\u0026thinsp;=\u0026thinsp;16), aphakic bullous keratopathy (5 eyes 9.6%; nDSEK n\u0026thinsp;=\u0026thinsp;3; DSEK\u0026thinsp;=\u0026thinsp;2) as well as other less common etiologies, such as iridocorneal endothelial syndrome (8 eyes, 15.4%; nDSEK n\u0026thinsp;=\u0026thinsp;3; DSEK n\u0026thinsp;=\u0026thinsp;5), Fuchs\u0026rsquo; endothelial dystrophy (2 eyes 3.8%; DSEK n\u0026thinsp;=\u0026thinsp;2 ), corneal endotheliitis (3 eyes 5.7%; nDSEK n\u0026thinsp;=\u0026thinsp;1; DSEK n\u0026thinsp;=\u0026thinsp;2 ), unknown etiology (3 eyes, 5.7%; nDSEK n\u0026thinsp;=\u0026thinsp;2; DSEK n\u0026thinsp;=\u0026thinsp;1 ) as shown in Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e. The surgical history comprised a significant proportion of glaucoma surgery cases (15 eyes, accounting for 28.8% of the total), with the majority of these cases involving nDSEK (6 eyes) and DSEK (9 eyes). A smaller portion of the surgical history was attributed to ocular trauma cases (8 eyes, representing 15.4% of the total), including both nDSEK (5 eyes) and DSEK (3 eyes), (Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). Additionally, there were 2 cases (3.8%) related to a history of PK in which nDSEK was performed. There were no statistically significant differences found in the data related to age (P\u0026thinsp;=\u0026thinsp;0.759), sex (P\u0026thinsp;=\u0026thinsp;0.103), history of glaucoma surgery (P\u0026thinsp;=\u0026thinsp;0.571) and ocular trauma (P\u0026thinsp;=\u0026thinsp;0.533), indications (P\u0026thinsp;=\u0026thinsp;0.404), preoperative BCVA (P\u0026thinsp;=\u0026thinsp;0.830), and ECD (P\u0026thinsp;=\u0026thinsp;0.102), (Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\u0026nbsp;\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eDemographic characteristics and baseline clinical data of patients\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003enDSEK (n\u0026thinsp;=\u0026thinsp;24)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDSEK(n\u0026thinsp;=\u0026thinsp;28)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAge (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e60.8\u0026thinsp;\u0026plusmn;\u0026thinsp;15.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e62.1\u0026thinsp;\u0026plusmn;\u0026thinsp;15.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.759\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10(41.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e18(64.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.103\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePreoperative BCVA (LogMAR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.71\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.830\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDonor ECD (cells/mm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2857\u0026thinsp;\u0026plusmn;\u0026thinsp;120\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2914\u0026thinsp;\u0026plusmn;\u0026thinsp;125\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.102\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHistory of glaucoma surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6(25%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9(32.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.571\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHistory of ocular trauma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5(20.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3(10.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.533\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eIndications\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.404\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDecompensation after cataract surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e18(75%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e18(64.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOther etiologies\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6(25%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10(35.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\"\u003enDSEK\u0026thinsp;=\u0026thinsp;non-Descemet stripping endothelial keratoplasty; DSEK\u0026thinsp;=\u0026thinsp;Descemet stripping endothelial keratoplasty; BCVA\u0026thinsp;=\u0026thinsp;best corrected visual acuity; LogMAR\u0026thinsp;=\u0026thinsp;logarithm of minimal angle of resolution; ECD\u0026thinsp;=\u0026thinsp;endothelial cell density; decompensation after cataract surgery including pseudophakic (nDSEK n\u0026thinsp;=\u0026thinsp;15; DSEK n\u0026thinsp;=\u0026thinsp;16) and aphakic bullous keratopathy (nDSEK n\u0026thinsp;=\u0026thinsp;3; DSEK\u0026thinsp;=\u0026thinsp;2); other etiology including iridocorneal endothelial syndrome (nDSEK n\u0026thinsp;=\u0026thinsp;3; DSEK n\u0026thinsp;=\u0026thinsp;5),Fuchs\u0026rsquo; endothelial dystrophy (DSEK n\u0026thinsp;=\u0026thinsp;2 ), corneal endotheliitis (nDSEK n\u0026thinsp;=\u0026thinsp;1; DSEK n\u0026thinsp;=\u0026thinsp;2 ), unknown etiology (nDSEK n\u0026thinsp;=\u0026thinsp;2; DSEK n\u0026thinsp;=\u0026thinsp;1 )\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003c/p\u003e\n\u003cp\u003eGeneral observation\u003c/p\u003e\n\u003cp\u003eAll patients experienced pain relief and felt comfortable with the disappeared corneal edema and bullae within 1\u0026thinsp;~\u0026thinsp;3 months after the successful surgery. There were no visible differences observed in the clear cornea when examined under a slit-lamp microscope between the eyes that underwent nDSEK and DSEK procedures. Additionally, the donor lenticule and recipient bed were securely attached. Figure \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e depicts representative photographs captured using a slit-lamp microscope and AS-OCT technology.\u003c/p\u003e\n\u003cp\u003eVisual outcomes\u003c/p\u003e\n\u003cp\u003eData analysis on BCVA did not include 4 eyes that experienced primary graft failure (nDSEK n\u0026thinsp;=\u0026thinsp;2;DSEK n\u0026thinsp;=\u0026thinsp;2) and 3 eyes with significant visual impairments due to coexisting conditions (nDSEK n\u0026thinsp;=\u0026thinsp;1, combined optic atrophy ; DSEK n\u0026thinsp;=\u0026thinsp;2, combined optic atrophy and macular degeneration). The visual outcomes showed gradual improvement in the months following surgery, steadily progressing until the 6-month mark for the majority of nDSEK and DSEK eyes. However, this progress was not observed in cases where patients also had serious macular degeneration or optic atrophy. The mean postoperative BCVA (logMAR) significantly improved from the preoperative 1.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23 to 0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18 at postoperative 3 months, 0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20 at postoperative 6 months, 0.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 at postoperative 12 months respectively in nDSEK eyes. In addition, the mean postoperative BCVA (logMAR) improved from the preoperative 1.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 to 0.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 at postoperative 3 months, 0.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18 at postoperative 6 months, 0.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 at postoperative 12 months respectively in DSEK eyes. Despite this, no statistically significant differences were found between the nDSEK and DSEK eyes in terms of statistical significance at the corresponding time intervals (P\u0026thinsp;=\u0026thinsp;0.263; Table \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e; Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eChanges in BCVA and ECD at different time points after the surgery\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"4\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003enDSEK n\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDSEK n\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eChanges in BCVA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.263\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePreoperative BCVA (LogMAR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23 21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBCVA at 3 months (LogMAR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18 21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBCVA at 6 months (LogMAR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20 21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18 24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBCVA at 12 months (LogMAR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eChanges in ECD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.185\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePreoperative ECD (cells/mm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2848\u0026thinsp;\u0026plusmn;\u0026thinsp;108 22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2905\u0026thinsp;\u0026plusmn;\u0026thinsp;132 26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eECD at 3 months(cells/mm\u003csup\u003e2\u003c/sup\u003e)(ECL%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1612\u0026thinsp;\u0026plusmn;\u0026thinsp;131(43%) 22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1725\u0026thinsp;\u0026plusmn;\u0026thinsp;189 (41%) 26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eECD at 6 months(cells/mm\u003csup\u003e2\u003c/sup\u003e)(ECL%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1382\u0026thinsp;\u0026plusmn;\u0026thinsp;166(52%) 22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1475\u0026thinsp;\u0026plusmn;\u0026thinsp;296 (49%) 26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eECD at 12 months(cells/mm\u003csup\u003e2\u003c/sup\u003e)(ECL%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1176\u0026thinsp;\u0026plusmn;\u0026thinsp;269 (59%) 18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1235\u0026thinsp;\u0026plusmn;\u0026thinsp;368(57%) 22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\"\u003enDSEK\u0026thinsp;=\u0026thinsp;non-Descemet stripping endothelial keratoplasty; DSEK\u0026thinsp;=\u0026thinsp;Descemet stripping endothelial keratoplasty; BCVA\u0026thinsp;=\u0026thinsp;best-corrected visual acuity; LogMAR\u0026thinsp;=\u0026thinsp;logarithm of minimal angle of resolution; ECD\u0026thinsp;=\u0026thinsp;endothelial cell density; ECL\u0026thinsp;=\u0026thinsp;endothelial cell loss. Data for analysis on the preoperative BCVA excluded 4 eyes resulting from the primary graft failure (nDSEK n\u0026thinsp;=\u0026thinsp;2;DSEK n\u0026thinsp;=\u0026thinsp;2) and 3 eyes with serious visual impairing optic atrophy or affected with macular degeneration co-morbidity (nDSEK n\u0026thinsp;=\u0026thinsp;1;DSEK n\u0026thinsp;=\u0026thinsp;2), Preoperative ECD excluded 4 eyes resulting from the primary graft failure (nDSEK n\u0026thinsp;=\u0026thinsp;2;DSEK n\u0026thinsp;=\u0026thinsp;2)\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003eEndothelial cell density and endothelial cell loss (ECL)\u003c/p\u003e\n\u003cp\u003eThe Cases with primary graft failure (nDSEK n\u0026thinsp;=\u0026thinsp;2; DSEK n\u0026thinsp;=\u0026thinsp;2) were omitted from the analysis of donor ECD data. After the surgery, the mean donor ECD decreased from the preoperative 2848\u0026thinsp;\u0026plusmn;\u0026thinsp;108 cells/mm\u003csup\u003e2\u003c/sup\u003e to 1612\u0026thinsp;\u0026plusmn;\u0026thinsp;131 cells/mm\u003csup\u003e2\u003c/sup\u003e(ECL 43%)at postoperative 3 months postoperative,1382\u0026thinsp;\u0026plusmn;\u0026thinsp;166 cells/mm\u003csup\u003e2\u003c/sup\u003e (ECL 52%)at 6 months postoperative and 1176\u0026thinsp;\u0026plusmn;\u0026thinsp;269 cells/mm\u003csup\u003e2\u003c/sup\u003e(ECL 59%) at 12 months postoperative respectively in nDSEK eyes. Similarly, in DSEK eyes the mean donor ECD decreased from the preoperative 2905\u0026thinsp;\u0026plusmn;\u0026thinsp;132 cells/mm\u003csup\u003e2\u003c/sup\u003e to 1725\u0026thinsp;\u0026plusmn;\u0026thinsp;189 cells/mm\u003csup\u003e2\u003c/sup\u003e ( ECL 41%) at 3 months postoperative, 1475\u0026thinsp;\u0026plusmn;\u0026thinsp;296 (ECL 49%) cells/mm\u003csup\u003e2\u003c/sup\u003e at 6 months postoperative and 1235\u0026thinsp;\u0026plusmn;\u0026thinsp;368 cells/mm\u003csup\u003e2\u003c/sup\u003e (ECL 57%) at 12 months postoperative respectively. However, there were no statistically significant differences found between the nDSEK and DSEK eyes at the same time points ( P\u0026thinsp;=\u0026thinsp;0.185; Table \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e; Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eComplications\u003c/p\u003e\n\u003cp\u003eGraft dislocation occurred in two eyes (8.3%) after nDSEK and one eye (3.6%) after DSEK respectively on the postoperative days 1 to day 2. However, successful rebubbling was conducted in all these instances. The graft dislocation rates did not show any significant differences between nDSEK and DSEK eyes, ( P\u0026thinsp;=\u0026thinsp;0.891; Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). Acute high intraocular pressure occurred in one eye (4.2%) after nDSEK and two eyes (7.1%) after DSEK respectively even routinely had Peripheral iridectomy, This issue was effectively addressed by either removing excess air that caused blockage in the pupil or by performing the angle reformation due to secondary angle closure from air migration posterior to the iris between the postoperative days 0 and day 1. There were no statistically significant differences found in the rate of acute high intraocular pressure between the nDSEK and DSEK eyes (P\u0026thinsp;=\u0026thinsp;1; Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). Two eyes (8.3%) experienced primary graft failure following nDSEK, while two eyes (7.1%) experienced it after DSEK. Within six months, all these eyes underwent regrafting using fresh endothelial donor tissue through either nDSEK or DSEK, except for one DSEK eye which required penetrating keratoplasty at 12 months after the initial surgery. However, there were no statistically significant differences found in the primary graft failure rates between the nDSEK and DSEK eyes (P\u0026thinsp;=\u0026thinsp;1; Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). Graft rejection was observed in 8.3% of eyes following nDSEK, while only 3.6% of eyes experienced rejection after DSEK. However, the study found no significant differences in the occurrence of endothelial graft rejection between the nDSEK and DSEK eyes ( P\u0026thinsp;=\u0026thinsp;0.891; Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). All these rejection cases were managed with frequent topical prednisolone acetate eye drops and subconjunctival injections of dexamethasone. Despite positive response in one nDSEK eye, the other cases eventually experienced secondary graft failure. However, no serious complications such as suprachoroidal hemorrhage, postoperative endophthalmitis, and interface infection were observed in either nDSEK or DSEK eyes during the follow-up period.\u003c/p\u003e\n\u003cp\u003e\u003c/p\u003e\u0026nbsp;\u003ctable id=\"Tab3\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComplications observed after the surgery\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003enDSEK (n\u0026thinsp;=\u0026thinsp;24)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDSEK (n\u0026thinsp;=\u0026thinsp;28)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGraft dislocation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2(8.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1(3.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.891\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAcute high introcular pressure\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1(4.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2(7.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePrimary graft failure\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2(8.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2(7.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGraft rejection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2(8.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1(3.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.891\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003c/p\u003e\n\u003cp\u003enDSEK, non-Descemet stripping endothelial keratoplasty; DSEK, Descemet stripping endothelial keratoplasty.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eVisual outcomes\u003c/p\u003e \u003cp\u003eIn the present study, postoperative BCVA (logMAR) in both nDSEK eyes ( 0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18 at postoperative 3 months, 0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20 at postoperative 6 months, 0.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 at postoperative 12 months respectively) and DSEK eyes (0.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 at postoperative 3 months, 0.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18 at postoperative 6 months, 0.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 at postoperative 12 months respectively) showed improvement, with the exception of cases where there were other concomitant pathologies such as serious macular degeneration and optic atrophy. The improvements in BCVA were significant and comparable between the two groups. The postoperative visual improvement observed in this study was comparable with that reported in other previous studies. For instance, a study by Price group [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] found that after DSEK, the mean BCVA (logMAR) was 0.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34 at the 3 months examination, and 0.39\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34 at the 6 months examination. These results demonstrate a significant improvement compared to the initial BCVA of 0.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.54 before the surgery. In Zhang\u0026rsquo;s study [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], results demonstrated that after nDSEK, the mean BCVA (logMAR) improved from 1.70 preoperatively to 0.54 at 3 months, 0.46 at 6 months, and 0.37 at 1 year after the surgery, respectively. Moreover, in a comparative study by Mohamed et al. [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], the mean BCVA (logMAR) at 6 months postoperatively in the DSEK and nDSEK eyes were found to be 0.18 and 0.44, respectively, with no significant difference observed between them. A recent study conducted by Omoto et al [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] compared the long-term outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK) and non-Descemet stripping automated endothelial keratoplasty (nDSAEK). The study found that the mean preoperative BCVA (logMAR) of nDSAEK and DSAEK eyes were 1.08 and 1.11, respectively. However, these values significantly improved over time to 0.238 and 0.190, 0.126 and 0.157, and 0.097 and 0.070 at 1, 3, and 5 years, respectively. There were no statistically significant differences between nDSAEK and DSAEK in BCVA improvement, suggesting that stripping of the recipient Descemet membrane may not be necessary and has minimal influence on long-term results. We concluded that there were multiple factors that contributed to the lower level of visual improvement in our study compared to the previous studies. For example, the mean preoperative BCVA was very poor, primarily caused by significant corneal swelling due to the long waiting time for the surgery. Interestingly, our findings contradicted the previous reports that stated Fuchs' endothelial dystrophy as the most common indication for keratoplasty1 [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Instead, our study revealed a higher prevalence of pseudophakic bullous keratopathy/aphakic bullous keratopathy. Additionally, other etiologies like iridocorneal endothelial syndrome were not less common, and a significant number of cases had a history of glaucoma surgery. Moreover, some of the cases in our study had a history of previous cataract-vitreous-retinal surgery due to ocular trauma and had complications like severe corneal edema, abnormal anterior segment such as anterior synechia, aphakia, iris defect, and concomitant pathology such as serious macular degeneration as well as optic atrophy. These complications also affected the clinical results such as postoperative visual improvement. However, we found in the present study that the visual improvement was similar for both nDSEK and DSEK eyes when performed by the same surgeon. We found that nDSEK can potentially provide similar visual improvement as classic DSEK, except in cases of Fuchs' endothelial dystrophy and obvious Descemet membrane abnormalities. The advantage of nDSEK is that it eliminates the need for descemetorrhexis, and interestingly, we observed that preserving the recipient's Descemet membrane does not impact visual recovery.\u003c/p\u003e \u003cp\u003eEndothelial cell density and endothelial cell loss\u003c/p\u003e \u003cp\u003eAccording to our study, there was a significant decrease in donor endothelial cell density (ECD) in both nDSEK and DSEK eyes at various postoperative time points. Specifically, in nDSEK eyes, the ECD decreased from the preoperative 2848\u0026thinsp;\u0026plusmn;\u0026thinsp;108 cells/mm\u003csup\u003e2\u003c/sup\u003e to 1612\u0026thinsp;\u0026plusmn;\u0026thinsp;131 cells/mm\u003csup\u003e2\u003c/sup\u003e (ECL 43%) at 3 months postoperative, 1382\u0026thinsp;\u0026plusmn;\u0026thinsp;166 cells/mm\u003csup\u003e2\u003c/sup\u003e (ECL 52%) at 6 months postoperative and 1176\u0026thinsp;\u0026plusmn;\u0026thinsp;269 cells/mm\u003csup\u003e2\u003c/sup\u003e (ECL 59%) at 12 months postoperative. Similarly, in DSEK eyes, the ECD decreased from the preoperative 2905\u0026thinsp;\u0026plusmn;\u0026thinsp;132 cells/mm\u003csup\u003e2\u003c/sup\u003e to 1752\u0026thinsp;\u0026plusmn;\u0026thinsp;189 cells/mm\u003csup\u003e2\u003c/sup\u003e (ECL 41%) at 3 months postoperative, 1475\u0026thinsp;\u0026plusmn;\u0026thinsp;296 cells/mm\u003csup\u003e2\u003c/sup\u003e (ECL 49%) at 6 months postoperative and 1235\u0026thinsp;\u0026plusmn;\u0026thinsp;368 cells/mm\u003csup\u003e2\u003c/sup\u003e (ECL57%) at 12 months postoperative. However, there were no statistically significant differences in ECD between nDSEK and DSEK eyes at the same time point. Interestingly, the ECL in both nDSEK and DSEK eyes in the present study was found to be higher than those reported in the previous studies. For instance, in Price\u0026rsquo; study on DSEK, the ECL was 34% at 6 months, 36% at 12 months,41% at 24 months [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Moreover, in Mohamed\u0026rsquo;s study, the ECL in the DSEK and nDSEK eyes was 28.1%\u0026plusmn;17.1% and 23.6%\u0026plusmn;8.3%, respectively [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. We infer that the increased loss of endothelial cells in our recent study may be due to various factors following nDSEK and DSEK procedures. First, eye conditions such as prior cataract-vitreous-retinal surgery (ocular trauma history ), glaucoma drainage implantation, complicated eye with severe corneal edema, abnormal anterior segment such as anterior synechia, aphakia, and iris defect, can make endothelial keratoplasty more challenging for these complex cases. Second, factors related to the surgery itself, such as incision size, donor tissue preparation, as well as graft delivery devices, rebubbling for donor tissue dislocation and the learning curve of EK for the surgeon [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] also associated with postoperative corneal endothelial loss. All of these factors can affect the ECL and lead to higher ECL as observed in our present study.\u003c/p\u003e \u003cp\u003eComplications\u003c/p\u003e \u003cp\u003eThe most common complication encountered in endothelial keratoplasty is graft dislocation, which occurs at a wide range of rates, from 0\u0026ndash;80%, with an average dislocation rate of 14.5% [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Several factors, such as the surgeon's experience, viscoelastic in the graft interface, geometric mismatch between donor and recipient curvatures that cause a portion of the donor to arc away from the recipient, residual strands of either stroma or Descemet membrane that prevent tight apposition of the donor against the recipient all can contribute to the influence on the surgery [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. In the present study, graft dislocation occurred in 8.3% nDSEK eyes and 3.6% DSEK eyes, with no significant variation between the nDSEK and DSEK groups. Our study seems to indicate that the preservation of the recipient's Descemet membrane does not impact the attachment of the donor lenticule to the recipient bed. However, this factor could potentially influence the rate of graft dislocation.\u003c/p\u003e \u003cp\u003eAcute high intraocular pressure was observed in 1 eye (4.2%) after nDSEK and 2 eyes (7.1%) after DSEK, in spite of the routine peripheral iridectomy performed. However, there were no significant statistical differences between the occurrence of this complication in nDSEK and DSEK eyes. The rate of acute high intraocular pressure was relatively lower, as compared to the 10.5% reported in the study conducted by Daubert et al [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] but higher than 2.8% reported by study of Basaket al [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. The higher rate of acute high intraocular pressure in our present study could be associated with the use of a full intracameral air tamponade to obtain firm attachment of the donor at the end of surgery without releasing the air postoperatively. This method may result in elevated intraocular pressure due to air-induced pupillary block and occlusion of iridotomy not only in nDSEK but also in DSEK eyes.\u003c/p\u003e \u003cp\u003eThe literature shows a broad range of primary graft failure rates, ranging from 0\u0026ndash;29%, with an average rate of 5% [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In the present study, there were no statistically significant differences observed in the occurrence of primary graft failure between nDSEK and DSEK eyes, as two eyes (8.3%) with primary graft failure were observed in nDSEK eyes, while two eyes (7.1%) experienced primary graft failure in DSEK eyes. The rate of primary graft failure in our study exceeded the percentages reported by Price, which were 5% and 6% [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Several key factors contributing to complications during anterior segment surgery include the surgeon's level of expertise in performing EK, the presence of surgical eyes with complicated abnormal anterior segment, poor quality of donor tissue, and donor tissue preparation [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. In our study, the higher rate of primary graft failure could be attributed to the intricacy of the surgical procedure and the challenging learning process of EK for surgeons.\u003c/p\u003e \u003cp\u003eWe found that graft rejection occurred in two eyes (8.3%) after nDSEK in comparison to one eye (3.6%) after DSEK. However, no significant statistical difference in graft rejection rates was observed. The graft rejection rate (8.3%) after nDSEK was found to be higher in comparison to Chaurasia\u0026rsquo; report [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] of 4.3% after nDSEK and Zhang\u0026rsquo; report [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] of 3.1% after nDSEK. The factors that increase the risk of corneal rejection include host bed vascularity due to longer corneal edema in bullous keratopathy eye, clinical history of glaucoma, previous surgeries such as glaucoma surgery or anterior segment surgery, anterior iris synechiae, vitreous adhesion, re-grafts, multiple surgeries performed simultaneously [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Moreover, different postoperative steroid management and the duration of follow-up posed challenges in directly comparing rejection rates across different studies. Thus, the rejection rate in various studies may vary due to the impact of these aforementioned factors.\u003c/p\u003e \u003cp\u003eLimitations\u003c/p\u003e \u003cp\u003eThere are several limitations of the current study, such as retrospective study, small sample size, heterogeneity in terms of indication for transplant and ocular co-morbidities, and short duration of follow-up. Future well-designed randomized controlled trial with large sample sizes and an extensive follow-up duration are needed to verify the results of this study.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn conclusion, our study found that nDSEK effectively eliminated the need for descemetorrhexis in treating bullous keratopathy. Despite this modification, the clinical effectiveness and safety of nDSEK remained comparable to traditional DSEK. Therefore, we consider nDSEK to be a valuable option for managing bullous keratopathy, particularly in situations where resources are limited, excluding cases of Fuchs' endothelial dystrophy and significant abnormalities in the Descemet membrane.\u003c/p\u003e"},{"header":"Declarations","content":" \u003cp\u003e \u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e \u003cp\u003eThis study was approved by the Medical Ethics Committee of the Nanning Aier Eye Hospital, China. This study was carried out in accordance with the principles of the Declaration of Helsinki, and all patients provided informed consent. All methods were carried out in accordance with relevant guidelines and regulations.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent for publication\u003c/strong\u003e \u003cp\u003e Informed consent was obtained from all subjects for publication of identifying\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eThe authors have no conflicts of interest to disclose.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis study was supported by the Self-funded Scientific Research Project of Guangxi Zhuang Autonomous Region Health Commission (grant number:Z20201374).\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eThe study was conceptualized and designed by M.H. ; Collection of data (G.Y., T.H., Z.W.); Analysis of data (J.T., Z.Z., D.W.); Preparation of manuscript (M.H.). All authors reviewed and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgments\u003c/h2\u003e \u003cp\u003eThe author would like to thank all the reviewers who participated in the review and MJEditor (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e\u003ca href=\"http://www.mjeditor.com\" target=\"_blank\"\u003ewww.mjeditor.com\u003c/a\u003e\u003c/span\u003e\u003cspan address=\"http://www.mjeditor.com\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e) for its linguistic assistance during the preparation of this manuscript.\u003c/p\u003e\u003ch2\u003eAvailability of data and materials\u003c/h2\u003e \u003cp\u003eThe data presented in this study are available on request from the corresponding author.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003ePrice FW Jr, Price MO. Endothelial Keratoplasty to Restore Clarity to a Failed Penetrating Graft. Cornea. 2006;25(8):895\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang T, Li SW, Chen TH, He JL, Kang YW, Lyu FQ, Ning JH, Liu C. Clinical results of non-Descemet stripping endothelial keratoplasty. Int J Ophthalmol. 2017;10(2):223\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWajima H, Hayashi T, Kobayashi A, Nishino T, Mori N, Yokogawa H, Yamagami S. Sugiyama K.Graft rejection episodes after\u0026ensp;keratoplasty\u0026ensp;in. Japanese eyes Sci Rep. 2023;13(1):2635.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChaurasia S, Ramappa M, Sangwan VS. Clinical outcomes of nonDescemet stripping automated endothelial keratoplasty. Int Ophthalmol. 2012;32(6):571\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrice MO, Price FW Jr. Endothelial keratoplasty\u0026mdash;a review. Clin Exp Ophthalmol. 2010;38(2):128\u0026ndash;40.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrice MO, Price FW Jr.. Descemet\u0026rsquo;s Stripping with Endothelial Keratoplasty Comparative Outcomes with Microkeratome-Dissected and Manually Dissected Donor Tissue. Ophthalmology. 2006;113(11):1936\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHong Y, Peng RM, Wang M, Qu HQ, Hong J. Suture pull-through insertion techniques for Descemet stripping automated endothelial keratoplasty in Chinese phakic eyes: outcomes and complications. PLoS ONE. 2013;23(4):e61929.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLange C, Feltgen N, Junker B, Schulze-Bonsel K, Bach M. Resolving the clinical acuity categories hand motion and counting fingers using the Freiburg Visual Acuity Test (FrACT). Graefes Arch Clin Exp Ophthalmol. 2009;247:137\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrice FW Jr. Price MO.Descemet\u0026rsquo;s Stripping With Endothelial Keratoplasty in 50 Eyes: A Refractive Neutral Corneal Transplant. Refract Surg. 2005;21:339\u0026ndash;45.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMohamed A, Ks AR, Chaurasia S, Ramappa M. Outcomes of endothelial keratoplasty in pseudophakic corneal oedema: with or without Descemet\u0026rsquo;s membrane stripping. Br J Ophthalmol. 2016;100(6):754\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOmoto T, Toyono T, Inoue T, Shirakawa R, Yoshida J, Miyai T, Yamagami S, Usui T. Comparison of 5-Year Clinical Results of Descemet and Non-Descemet Stripping Automated Endothelial. Cornea. 2020;39(5):573\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTerry MA, Shamie N, Chen ES, Phillips PM, Shah AK, Hoar KL, Friend DJ. Endothelial keratoplasty for Fuchs' dystrophy with cataract: complications and clinical results with the new triple procedure. Ophthalmology. 2009;116(4):631\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDobbins KR, Price FW Jr, Whitson WE. Trends in the indications for penetrating keratoplasty in the Midwestern United States.Cornea. 2000;19(6):813\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrice MO, Price FW Jr. Endothelial cell loss after Descemet stripping with endothelial keratoplasty: influencing factors and 2-year trend. Ophthalmology. 2008;115:857\u0026ndash;65.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePatel SV. Graft Survival and Endothelial Outcomes in the New Era of Endothelial Keratoplasty. Exp Eye Res. 2012;95(1):40\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFajgenbaum MA, Hollick EJ. Descemet Stripping Endothelial Keratoplasty in Iridocorneal Endothelial Syndrome: Postoperative Complications and Long-Term Outcomes. Cornea. 2015;34:1252\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDaubert J, O'Brien TP, Adler E, Spierer O. Outcomes of complex Descemet Stripping Endothelial Keratoplasty performed by cornea fellows.BMC Ophthalmol. 2018, 30;18(1):281.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee WB, Jacobs DS, Musch DC, Kaufman SC, Reinhart WJ, Shtein RM. Descemet\u0026rsquo;s Stripping Endothelial Keratoplasty: Safety and Outcomes \u003cem\u003eA\u003c/em\u003e Report by the American Academy of Ophthalmology. Ophthalmology. 2009;116(9):1818\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrice FW Jr, Price MO. A Nonsurgical Treatment for Donor Dislocation After Descemet Stripping Endothelial Keratoplasty (DSEK).Cornea. 2006;25(8):991.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBasak SK, Basak S. Complications and management in Descemet's stripping endothelial keratoplasty: Analysis of consecutive 430 cases. Indian J Ophthalmol. 2014;62(2):209\u0026ndash;18.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMuijzer MB, van Luijk CM, van den Bogaerdt AJ, Kruit PJ, Groeneveld-van Beek E, Melles GRJ, Wisse RPL. Prospective evaluation of clinical outcomes between pre-cut corneal grafts prepared using a manual or automated technique: with one-year follow-up. Acta Ophthalmol. 2019;97(7):714\u0026ndash;20.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDi Zazzo A, Kheirkhah A, Abud TB, Goyal S, Dana R. Management of High-risk Corneal Transplantation. Surv Ophthalmol. 2017;62(6):816\u0026ndash;27.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Descemet stripping endothelial keratoplasty, non-Descemet stripping endothelial keratoplasty, bullous keratopathy","lastPublishedDoi":"10.21203/rs.3.rs-3886955/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3886955/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eEndothelial keratoplasty has evolved significantly through the utilization of different techniques. However, few studies have compared the clinical outcome between nDSEK (a modified version of the DSEK procedure known as non-Descemet stripping endothelial keratoplasty) and DSEK. This study aims to compare the potential efficacy and safety of nDSEK and DSEK in treating bullous keratopathy.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA retrospective comparative study included patients with bullous keratopathy underwent either nDSEK or DSEK between August 2017 and July 2022. These subjects were monitored for a period ranging from 6 to 36 months. The important factors such as best corrected visual acuity (BCVA), endothelial cell density (ECD), endothelial cell loss (ECL), and any complications that occurred during the follow-up period were recorded.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eA total of 52 eyes from 52 patients with bullous keratopathy were included. All subjects underwent either nDSEK (24 eyes) or DSEK (28 eyes). The mean BCVA (logMAR) showed significant improvement from the preoperative measurement of 1.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23 to 0.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 in nDSEK eyes and from the preoperative 1.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 to 0.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 in DSEK eyes respectively at postoperative 12 months. However, there was no statistically significant difference in improvement of BCVA between the nDSEK and DSEK eyes (P\u0026thinsp;=\u0026thinsp;0.263). The mean donor ECD decreased from the preoperative 2848\u0026thinsp;\u0026plusmn;\u0026thinsp;108 cells/mm\u003csup\u003e2\u003c/sup\u003e to 1176\u0026thinsp;\u0026plusmn;\u0026thinsp;269 cells/mm\u003csup\u003e2\u003c/sup\u003e (ECL 59%) in nDSEK eyes and from the preoperative 2905\u0026thinsp;\u0026plusmn;\u0026thinsp;132 cells/mm\u003csup\u003e2\u003c/sup\u003e to 1235\u0026thinsp;\u0026plusmn;\u0026thinsp;368 cells/mm\u003csup\u003e2\u003c/sup\u003e (ECL 57%) in DSEK eyes respectively at postoperative 12 months, with no significant difference between the nDSEK and DSEK eyes (P\u0026thinsp;=\u0026thinsp;0.185). The occurrence of various complications such as graft dislocation (8.3% in nDSEK eyes vs 3.6% in DSEK eyes, P\u0026thinsp;=\u0026thinsp;0.891), acute high introcular pressure (4.2% in nDSEK eyes vs 7.1% in DSEK eyes, P\u0026thinsp;=\u0026thinsp;1), primary graft failure (8.3% in nDSEK eyes vs 7.1% in DSEK eyes, P\u0026thinsp;=\u0026thinsp;1), graft rejection (8.3% in nDSEK eyes vs 3.6% in DSEK eyes, P\u0026thinsp;=\u0026thinsp;0.891) did not differ significantly between the nDSEK and DSEK eyes.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003enDSEK eliminated the descemetorrhexis step but yielded a comparable clinical outcome in terms of both effectiveness and safety when compared to DSEK for treating bullous keratopathy.\u003c/p\u003e","manuscriptTitle":"Comparative study of efficacy and safety between nDSEK and DSEK for bullous keratopathy","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-01-24 18:54:22","doi":"10.21203/rs.3.rs-3886955/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"0ade9408-275f-4a74-ae2d-40e0f6341426","owner":[],"postedDate":"January 24th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-09-13T07:53:59+00:00","versionOfRecord":[],"versionCreatedAt":"2024-01-24 18:54:22","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3886955","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3886955","identity":"rs-3886955","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}