Acute Hydrops After Bowman Layer Transplantation for Keratoconus May Indicate that Descemet Membrane Rupture Is Secondary to Hydrops.

PURPOSE: The aim of this study was to review the postoperative course and imaging features of 7 eyes that presented with corneal hydrops after Bowman layer (BL) transplantation was performed for advanced keratoconus to determine the potential mechanisms of hydrops formation. METHODS: A retrospective analysis was performed of 7 eyes of 5 patients with advanced keratoconus that underwent midstromal BL transplantation at 2 tertiary referral centers and developed acute corneal hydrops on average 64 (±30) months (range 14-104 months) postoperatively. Corneal tomography and anterior segment optical coherence tomography (AS-OCT) images were reviewed to document the postoperative and posthydrops course. RESULTS: For all eyes, the post-BL transplantation course was uneventful until hydrops development. Despite stable postoperative topographies in 5 of 7 eyes, eyes developed hydrops with typical hypodense areas on AS-OCT that were limited to the stromal layers posterior to the BL graft. With AS-OCT (6/7 eyes), 2 eyes showed a break in Descemet membrane, whereas Descemet membrane was intact across the cornea in 2 eyes; in 2 eyes, the images were inconclusive. All patients admitted to continued eye rubbing, and all but 1 had a clinically significant allergy and/or atopic constitution. Most eyes (5/7) showed a relatively quick (visual) recovery within 1 to 4 months after hydrops. CONCLUSIONS: Hydrops formation in keratoconic corneas after midstromal BL transplantation may indicate that a break in Descemet membrane is secondary to hydrops development (and not vice versa). With a midstromal BL graft in situ limiting hydrops dimensions, resolution of the hydrops seemed relatively quick with recovery to prehydrops visual acuity in most eyes.

Effect of Six-Month Postoperative Endothelial Cell Density on Graft Survival after Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To analyze if 6-month endothelial cell density (ECD) affects long-term ECD outcome and graft survival 5 years after Descemet membrane endothelial keratoplasty (DMEK) in eyes with Fuchs endothelial corneal dystrophy (FECD). DESIGN: Retrospective cohort study. PARTICIPANTS: A total of 585 DMEK eyes were included. The study group was divided into 4 groups based on 6-month ECD quartiles: group 1 (n = 146) with 313 to 1245 cells/mm2, group 2 (n = 148) with 1246 to 1610 cells/mm2, group 3 (n = 145) with 1611 to 1938 cells/mm2, and group 4 (n = 146) with 1939 to 2760 cells/mm2. Group 1 was further split into subgroups 1a (n = 36) with 6-month ECD of ≤828 cells/mm2, 1b (n = 37) with 829 to 1023 cells/mm2, 1c (n = 37) with 1024 to 1140 cells/mm2, and 1d (n = 36) 1141 to 1245 cells/mm2. METHODS: Descemet membrane endothelial keratoplasty. MAIN OUTCOME MEASURES: Long-term ECD, graft survival, and postoperative complication rates. RESULTS: For group 1, 6-month ECD decreased from 951 (±233) cells/mm2 (n = 146) to 735 (±216) cells/mm2 (n = 99) at 5 years postoperatively. Group 1 graft survival probability was 0.95 (95% confidence interval [CI], 0.91-0.99] at 5 years postoperatively, which was lower than for groups 2 to 4 (P = 0.001). Five-year graft survival in subgroup 1a was 0.79 (95% CI, 0.67-0.94), which was lower than in subgroups 1b to 1d (P = 0.001). Preoperative ECD did not influence graft survival (P = 0.400), and higher 6-month ECD values were associated with lower graft failure rates (hazard ratio, 0.994; 95% CI, 0.99-1.00; P = 0.001). CONCLUSIONS: Six-month ECD is associated with DMEK graft survival. High early cell loss after DMEK negatively affects long-term ECD outcome and graft survival. Grafts in the lowest 6-month ECD subgroup (≤828 cells/mm2) are at higher risk of failure within 5 years after DMEK. To ensure sufficiently high 6-month ECD, preoperative graft quality assessment should be optimized, and cellular stress induced to the graft should be minimized. Additionally, developing therapeutic options for the treatment of low postoperative ECD could further improve DMEK graft longevity.

Bowman Layer Onlay Grafting: Proof-of-Concept of a New Technique to Flatten Corneal Curvature and Reduce Progression in Keratoconus.

PURPOSE: The aim of this study was to describe a new surgical technique for flattening the corneal curvature and to reduce progression in eyes with advanced progressive keratoconus (KC) by using Bowman layer (BL) onlay grafting and to report on the preliminary outcomes of this procedure. METHODS: In this prospective interventional case series, 5 patients with advanced progressive KC underwent BL onlay grafting. After removal of the epithelium, a BL graft was placed and "stretched" onto the stroma, and a bandage lens was placed to cover the BL graft. In 1 case, BL onlay grafting could be performed immediately after ultraviolet corneal crosslinking; all other eyes were ineligible for ultraviolet corneal crosslinking. Best spectacle- and/or best contact lens-corrected visual acuity, refraction, biomicroscopy, corneal tomography, anterior segment optical coherence tomography, and complications were recorded at 1 week and at 1, 3, 6, 9, and 12 to 15 months postoperatively. RESULTS: All 5 surgeries could be performed successfully. Average maximum keratometry went from 75 diopters (D) preoperatively to 70 D at 1 year postoperatively. All eyes showed a completely reepithelialized and a well-integrated graft. Best spectacle-corrected visual acuity improved at least 2 Snellen lines (or more) in 3 of 5 cases and best contact lens-corrected visual acuity remained stable, improving by 3 Snellen lines in case 1 at 15 months postoperatively. Satisfaction was high, and all eyes again had full contact lens tolerance. CONCLUSIONS: BL onlay grafting may be a feasible surgical technique, providing up to -5 D of corneal flattening in eyes with advanced KC.

Use of Corneas From Septic Donors for Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To evaluate the suitability of corneas from septic donors for transplantation by analyzing the discard rate in the eye bank and the clinical outcome of Descemet membrane endothelial keratoplasty (DMEK) using organ-cultured corneal grafts from septic versus nonseptic donors. METHODS: This retrospective study included 1554 corneas of which 456 corneas (29%) were from septic and 1072 corneas (69%) from nonseptic donors [for 26 corneas (2%) sepsis status was unknown]. The clinical outcome at 6 months after DMEK was evaluated for 82 grafts (26 from septic and 56 from nonseptic donors). Outcome measures were endothelial cell density, central corneal thickness, and postoperative complications. RESULTS: Primary discard rates were higher for corneas from septic than from nonseptic donors (32.9% vs. 24.5%, P = 0.001). The main discard reason was poor endothelial cell quality for both septic (13.8%) and nonseptic (11.8%) donor corneas. Eye bank contamination rates for septic and nonseptic donor corneas were 1.1% and 1.7%, respectively (P = 0.102). After DMEK, donor endothelial cell density at 6m postoperatively was comparable between grafts from septic and nonseptic donors (1410 ± 422 cells/mm vs. 1590 ± 519 cells/mm, P = 0.140). No differences in 6m central corneal thickness and in the rebubbling rate were observed between the 2 groups (P = 0.780 and P = 0.396, respectively). None of the cases had graft rejection nor endophthalmitis in both groups. CONCLUSIONS: Provided strict adherence to donor screening and evaluation protocols, the use of organ-cultured corneas from septic donors for DMEK does not seem to increase the risk for recipients and allows for expansion of the donor pool for corneal tissue.

Prevention and Management of Descemet Membrane Endothelial Keratoplasty Complications.

PURPOSE: To describe Descemet membrane endothelial keratoplasty (DMEK) complications and strategies for their prevention and management. METHODS: Five hundred consecutive eyes with DMEK of 393 patients were reviewed in this retrospective study for intraoperative and postoperative complications up to 2 years and for corresponding management. RESULTS: Intraoperative challenges (difficult graft unfolding/positioning, high vitreous pressure, iris root hemorrhage, and Descemet membrane remnants) were encountered in 81 eyes (16.2%). Visually significant graft detachment was the main postoperative complication (34 eyes, 6.8%). Graft failure occurred in 8 eyes (1.6%). Other postoperative complications were an increase of intraocular pressure/decompensated glaucoma in 48 eyes (9.6%), significant cataract in 11 of 124 phakic eyes (8.9%), allograft rejection in 7 eyes (1.4%), cystoid macular edema in 5 eyes (1.0%), microbial keratitis in 2 eyes (0.4%), and retinal detachment in 1 eye (0.2%). Different strategies for prevention and management of these complications have been identified. CONCLUSIONS: DMEK shows acceptable rates of complications up to 2 years after surgery, which can be managed successfully. Anticipation of potential challenges and difficulties may aid in modifying intraoperative strategies for predisposed eyes. This knowledge may further minimize complications, in particular, when performing DMEK for an extended spectrum of corneal endothelial disorders.

Clinical outcome of 500 consecutive cases undergoing Descemet's membrane endothelial keratoplasty.

PURPOSE: To evaluate the clinical outcome of 500 consecutive cases after Descemet's membrane endothelial keratoplasty (DMEK) and the effect of technique standardization. DESIGN: Prospective, interventional case series at a tertiary referral center. PARTICIPANTS: A total of 500 eyes of 393 patients who underwent DMEK for Fuchs' endothelial corneal dystrophy, bullous keratopathy, or previous corneal transplant failure. METHODS: Best-corrected visual acuity (BCVA), endothelial cell density (ECD), pachymetry, and intraoperative and postoperative complications were evaluated before and 1, 3, and 6 months after DMEK. MAIN OUTCOME MEASURES: Comparison between 2 groups (group I: cases 1-250, outcome of "early surgeries" during transition to technique standardization; group II: cases 251-500, outcome of "late surgeries" after technique standardization). RESULTS: At 6 months, 75% of eyes reached a BCVA of ≥20/25 (≥0.8), 41% of eyes achieved ≥20/20 (≥1.0), and 13% of eyes achieved ≥20/18 (≥1.2) (n=418) when excluding eyes with ocular comorbidities (n=57). When including all available eyes at 6 months (n=475), 66% of eyes reached a BCVA of ≥20/25 (≥0.8), and 36% of eyes achieved ≥20/20 (≥1.0). Mean ECD decreased by 37% (±18%) to 1600 (±490) cells/mm2 (n=447) at 6 months (P<0.001). Postoperative pachymetry averaged 525 (±46) µm compared with 667 (±92) µm preoperatively (P<0.001). None of these parameters differed among the 2 groups (P>0.05). (Partial) graft detachment presented in 79 eyes (15.8%), and 26 eyes (5.2%) required a secondary surgery within the first 6 months (re-bubbling in 15, secondary keratoplasty in 11). With technique standardization, the postoperative complication rate decreased from 23.2% to 10% (P<0.001) and the rate of secondary surgeries decreased from 6.8% to 3.6% (P=0.10). CONCLUSIONS: In comparison with earlier endothelial keratoplasty techniques, DMEK may consistently give higher visual outcomes and faster visual rehabilitation. When used for the extended spectrum of endothelial pathologies, DMEK proved feasible with a relatively low risk of complications. Technique standardization may have contributed to a lower graft detachment rate and a relatively low secondary intervention rate. As such, DMEK may become the first choice of treatment in corneal endothelial disease.

Multicenter study of descemet membrane endothelial keratoplasty: first case series of 18 surgeons.

IMPORTANCE: Surgeons starting to perform Descemet membrane endothelial keratoplasty (DMEK) should be informed about the learning curve and experience of others. OBJECTIVE: To document the clinical outcome of standardized "no-touch" DMEK and its complications during the learning curves of experienced surgeons. DESIGN, SETTING, AND PARTICIPANTS: Retrospective multicenter study. A total of 431 eyes from 401 patients with Fuchs endothelial dystrophy (68.2%) and bullous keratopathy (31.8%) underwent DMEK performed by 18 surgeons in 11 countries. EXPOSURES: Descemet membrane endothelial keratoplasty. MAIN OUTCOMES AND MEASURES: Best-corrected visual acuity (BCVA), endothelial cell density, and intraoperative and postoperative complications. RESULTS: Of 275 eyes available for BCVA pooled analysis, BCVA improved in 258 eyes (93.8%), remained unchanged in 12 (4.4%), and deteriorated in 5 (1.8%). Two hundred seventeen eyes (78.9%) reached a BCVA of at least 20/40 (≥0.5), 117 (42.5%) at least 20/25 (≥0.8), and 61 (22.2%) at least 20/20 (≥1.0). Eyes with at least 6 months of follow-up (n = 176) reached similar BCVA outcomes. Mean (SD) decrease in endothelial cell density at 6 months was 47% (20%) (n = 133 [P = .02]). Intraoperative complications were rare, including difficulties in inserting, unfolding, or positioning of the graft (1.2%) and intraoperative hemorrhage (0.5%). The main postoperative complication was graft detachment (34.6%); 20.4% underwent a single rebubbling procedure, occasionally requiring a second (2.6%) and a third rebubbling (0.7%), and 17.6% underwent a second keratoplasty. CONCLUSIONS AND RELEVANCE: Our multicenter study showed that the standardized no-touch DMEK technique was feasible in most hands. The main challenges for surgeons starting to perform the procedure may be (1) to decide whether graft preparation is outsourced or performed during surgery, (2) to limit the number of graft detachments and secondary procedures, and (3) to obtain organ cultured donor corneal tissue.

Endothelial keratoplasty for bullous keratopathy in eyes with an anterior chamber intraocular lens.

PURPOSE: To describe how to approach eyes with phakic or pseudophakic bullous keratopathy that have an anterior chamber intraocular lens (AC IOL) using thin Descemet-stripping endothelial keratoplasty (thin-DSEK) or Descemet membrane endothelial keratoplasty (DMEK) with or without AC IOL removal. SETTING: Tertiary referral center. DESIGN: Comparative case series. METHODS: Descemet membrane endothelial keratoplasty or thin-DSEK was performed in pseudophakic eyes with iris-claw AC IOLs (Group 1) or in phakic eyes with angle-supported AC IOLs (Group 2). In both groups, DMEK was routinely performed except in eyes with insufficient corneal transparency or a high risk for graft detachment. Preoperative surgical considerations, postoperative corrected distance visual acuity (CDVA), endothelial cell density, and complications were documented. RESULTS: In Group 1, all AC IOLs were left in situ. In Group 2, AC IOLs were removed in 90% of cases. At 6 months, the CDVA was 20/40 (≥0.5 decimal) or better in 36% of eyes in Group 1 and 90% in Group 2. Graft detachment occurred in 20% of eyes and de novo or glaucoma exacerbation in 29%. CONCLUSIONS: Bullous keratopathy treatment in eyes with an AC IOL was feasible with DMEK. Intraocular lens removal may be required if postoperative complications are anticipated, but not to facilitate surgery. Overall, the surgical approach may aim to minimize postoperative complications; that is, thin-DSEK in eyes with low visual potential and/or concomitant pathology and DMEK in eyes with a phakic AC IOL and normal visual potential.

Outcomes of phacoemulsification after Descemet membrane endothelial keratoplasty.

PURPOSE: To evaluate the feasibility and outcomes of phacoemulsification after Descemet membrane endothelial keratoplasty (DMEK) for Fuchs endothelial dystrophy and bullous keratopathy. SETTING: Tertiary referral center. DESIGN: Comparative case series. METHODS: The case notes of all phakic DMEK patients who subsequently had cataract surgery were reviewed, and data from a prospectively recorded database were analyzed. This included demographic details, visual acuity, corneal pachymetry, endothelial cell density (ECD), refractive outcomes, and complications. RESULTS: From a series of 106 consecutive phakic DMEK eyes, 5 eyes (4.7%) required phacoemulsification a mean of 9.2 months ± 3.7 (SD) (range 4 to 14 months) after the initial DMEK. All phacoemulsification procedures were uneventful, and no dislocations and/or detachments of the Descemet graft were observed. At 6 to 12 months, all eyes reached a corrected distance visual acuity of 20/30 (0.6) or better and were within ±0.50 diopter of the target refraction. Endothelial cell density decreased from a mean of 1535 ± 195 cells/mm(2) before phacoemulsification to 1158 ± 250 cells/mm(2) 6 to 12 months after phacoemulsification. No significant changes in pachymetry values were observed, and all corneas remained clear throughout the study. CONCLUSIONS: Phacoemulsification after DMEK can be performed with minimal risk for graft detachment. The postoperative refractive outcomes were predictable, and visual acuity is likely to improve; there was an acceptable decrease in ECD. FINANCIAL DISCLOSURE: Dr. Melles is a consultant to D.O.R.C. International BV/Dutch Ophthalmic USA. No author has a financial or proprietary interest in any material or method mentioned.

Do we overestimate the endothelial cell "loss" after descemet membrane endothelial keratoplasty?

PURPOSE: To evaluate how corneal deturgescence after Descemet membrane endothelial keratoplasty (DMEK) influences the posterior corneal surface area and the endothelial cell density (ECD) measurements. MATERIALS AND METHODS: A mathematical model was formulated to estimate the increase in posterior corneal surface area associated with postoperative corneal deturgescence and its effect on ECD measurements. Important input parameter for the model was the change in pachymetry from 1 h to 6 months after surgery. To this end, the clinical records of 25 patients (25 eyes) who underwent DMEK were reviewed retrospectively and the central corneal thickness (CCT) measurements taken after 1 h, 1 month, 3 months and 6 months were noted. ECD measurements before surgery and at 1, 3 and 6 months after surgery were also recorded and decrease in pachymetry and ECD loss were calculated. RESULTS: The average decrease in CCT due to corneal deturgescence was 267 µm (±39 µm), which corresponds to an 8.6% increase in total posterior corneal surface area, as calculated using our mathematical model. The stretching of the endothelial cell layer associated with this increase of posterior corneal surface area may result in an apparent endothelial cell "loss". This might account for approximately 25% of the observed average ECD decrease of 34% (±17%). CONCLUSIONS: The observed decrease in ECD within the first 6 months after DMEK may overestimate the actual loss of endothelial cells by about 8% due to increased posterior corneal surface area associated with postoperative corneal deturgescence.

Near complete visual recovery and refractive stability in modern corneal transplantation: Descemet membrane endothelial keratoplasty (DMEK).

OBJECTIVE: To report the 6 months results of a large prospective study on Descemet membrane endothelial keratoplasty (DMEK) for management of corneal endothelial disorders. METHODS: DMEK was performed in 300 consecutive eyes with Fuchs endothelial dystrophy, bullous keratopathy or previous corneal transplant failure. Best spectacle corrected visual acuity (BSCVA), refractive outcome and endothelial cell density (ECD) were evaluated before and at 1, 3, and 6 months after surgery. Intra- and postoperative complications were documented. RESULTS: At 6 months, 98% of eyes reached a BCVA of ≥20/40 (≥0.5), 79% ≥20/25 (≥0.8), 46% ≥20/20 (≥1.0), and 14% ≥20/18 (≥1.2) (n=221). The pre- to 6 months postoperative spherical equivalent (SE) showed a +0.33D (±1.08D) hyperopic shift (P=0.0000). Refractive stability was shown at 3 months after DMEK, i.e. no significant change in SE (P=0.0822) or refractive cylinder (P=0.6182) at 3 versus 6 months follow-up. Donor ECD showed a decrease from 2561 (±198)cells/mm(2) before, to 1674 (±518)cells/mm(2) at 6 months after surgery (n=251) (P=0.0000). The main complication was (partial) graft detachment occurring in 31 eyes (10%). Secondary ocular hypertension was seen in 13 eyes (6%): 6 induced by air-bubble dislocation posterior to the iris and 4 induced by steroids. Secondary cataract requiring phaco-emulsification developed in 3 out of 63 (5%) phakic eyes. CONCLUSIONS: DMEK may provide a refractively neutral near complete, rapid visual rehabilitation with ECDs similar to earlier endothelial keratoplasty techniques. This combined with a relatively low complication rate, would indicate that DMEK is a safe and effective treatment for corneal endothelial disorders.

Predictive value of optical coherence tomography in graft attachment after Descemet's membrane endothelial keratoplasty.

PURPOSE: To evaluate the predictive value of early anterior segment optical coherence tomography (AS-OCT) on graft adherence or detachment after Descemet's membrane endothelial keratoplasty (DMEK). DESIGN: Retrospective study of prospectively collected data at a tertiary referral center. PARTICIPANTS: A total of 87 eyes of 87 patients of a consecutive series of 142 DMEK surgeries. METHODS: Anterior segment OCT was performed within the first hour after DMEK and at 1 week, 1 month, 3 months, and 6 months, and for each time interval detachments were classified as "none," ≤ 1/3 detachment, >1/3 detachment of the total graft surface area, or "complete" detachment. Throughout the study, no rebubbling procedures were performed. MAIN OUTCOME MEASURES: Graft adherence at various postoperative time intervals. RESULTS: One-hour AS-OCT scans were more accurate at predicting the final 6-month graft adherence status than those at 1 week or 1 month. Grafts showing complete attachment or <1/3 detachment at 1 hour remained stable or improved in 73% of the cases at 1 week, 82% at 1 month, 86% at 3 months, and 90% at 6 months. All grafts attached at 1 week remained attached at 6 months. Graft detachments of >1/3 at 1 hour showed reattachment at 6 months in 25% of the cases, whereas 67.5% of the cases showed a persistent detachment of >1/3 at 6 months and 12.5% showed a complete detachment. CONCLUSIONS: The 1-hour AS-OCT scan showed the best predictive value on 6-month graft adherence status. The combined information of the 1-hour and 1-week AS-OCT scans may facilitate decision making about surgical reintervention after DMEK.

Large diameter descemet membrane endothelial keratoplasty in buphthalmic eyes.

PURPOSE: To report the outcomes of Descemet membrane endothelial keratoplasty (DMEK) using a large diameter graft in the management of endothelial decompensation in buphthalmic eyes. METHODS: Four eyes of 4 adults (1 man, 3 women) with bullous keratopathy and buphthalmos secondary to congenital glaucoma were treated with DMEK using posterior lamellar grafts with diameters ranging from 10 to 12 mm. The mean age was 31 (±9) years (range, 20-38 years). Mean follow-up time was 13.5 (±7.5) months (range, 6-24 months). Main outcome measures were best-corrected visual acuity (BCVA), intraocular pressure (IOP), pachymetry, endothelial cell density, and complications after surgery. RESULTS: In all eyes, there was improved corneal clarity with decrease in pachymetry. The final postoperative BCVA improved in most eyes. There was no significant change in IOP, with 3 eyes needing additional antiglaucoma medication. Endothelial cell loss ranged from 37% to 42%. Postoperative complications were early partial graft detachment in 2 eyes, one resolving spontaneously without intervention and the other requiring a rebubbling, and cataract formation requiring phacoemulsification in 1 eye. CONCLUSIONS: DMEK using a large or even full diameter Descemet membrane graft may be an effective treatment for bullous keratopathy in buphthalmic eyes. Partial graft detachment after surgery may be the main complication. Postoperative IOP control is mandatory, and BCVA may vary with ocular comorbidity unrelated to the transplanted cornea.