Purpose: To present a modified surgical technique to perform Descemet membrane endothelial keratoplasty (DMEK) in previously vitrectomized eyes and to analyze its safety and efficacy. Methods: A retrospective analysis of previously vitrectomized eyes that underwent DMEK at Toronto Western Hospital was performed. The modified DMEK technique that was used included placement of a posterior pars plana infusion to reduce fluctuations in the anterior chamber depth and its excessive deepening. Results: Twelve eyes of 12 patients (5 females and 7 males) aged 65.3 ± 21.5 years were included. Mean best-corrected visual acuity improved significantly from 1.72 ± 0.62 logMAR (mean Snellen ∼20/1040) preoperatively to 1.01 ± 0.64 logMAR (mean Snellen ∼20/200) at 6 months postoperatively (P = 0.017). Mean donor endothelial cell density was 2658 ± 229 cells/mm² preoperatively and 1732 ± 454 cells/mm² at 6 months after the procedure (mean percentage cell loss of 31.8%) (P = 0.046). There were no significant intraoperative complications, and no graft failures. One eye had graft detachment, which resolved after 2 rebubbling procedures. One eye had retinal detachment, which was corrected surgically. Conclusions: The use of posterior pars plana infusion in previously vitrectomized eyes stabilizes the anterior segment during DMEK, allowing for performance of DMEK surgery, and can potentially reduce intraoperative and postoperative complications.

Purpose: To evaluate 3-year outcomes of femtosecond laser-assisted Descemet membrane endothelial keratoplasty (F-DMEK) compared with manual Descemet membrane endothelial keratoplasty (M-DMEK) in patients with Fuchs endothelial corneal dystrophy (FECD). Methods: A retrospective, interventional study, including eyes with FECD and cataract that underwent either F-DMEK or M-DMEK combined with cataract extraction at either the Toronto Western Hospital or Kensington Eye Institute, and that had at least 18 months' follow-up was conducted. Exclusion criteria: complicated anterior segments, previous vitrectomy, previous keratoplasty, corneal opacity, or any other visually significant ocular comorbidity. Results: Included were 16 eyes of 15 patients in the F-DMEK group (average follow-up 33.0 ± 9.0 months) and 45 eyes of 40 patients in the M-DMEK group (average follow-up 32.0 ± 7.0 months). There were no issues with the creation of femtosecond descemetorhexis (in the F-DMEK group)—all descemetorhexis cuts were complete. Best spectacle-corrected visual acuity improvement did not differ significantly between the groups at 1, 2, and 3 years (P = 0.849, P = 0.465 and P = 0.936, respectively). Rates of significant detachment in F-DMEK and M-DMEK were 1 of 16 eyes (6.25%) and 16 of 45 eyes (35.6%) (P = 0.027). Rebubbling rates were 1 of 16 eyes (6.25%) and 15 of 45 eyes (33.3%) (P = 0.047). Cell-loss rates following F-DMEK and M-DMEK were 26.8% and 36.5% at 1 year (P = 0.042), 30.5% and 42.3% at 2 years (P = 0.008), 37% and 47.5% at 3 years (P = 0.057), respectively. Graft failure rate was 0% in F-DMEK and 8.9% in M-DMEK (all were primary failures; P = 0.565). Conclusions: F-DMEK showed good efficacy with reduced detachment, rebubble, and cell-loss rates, compared with M-DMEK.

Purpose: To compare 4-year survival outcomes of Descemet membrane endothelial keratoplasty (DMEK) and Descemet-stripping automated endothelial keratoplasty (DSAEK) in eyes with previous glaucoma surgery. Methods: This is a retrospective, comparative case series, including patients with previous trabeculectomy or glaucoma drainage device implantation, who later underwent either DMEK (n = 48) or DSAEK (n = 41). Follow-up was limited to 12 to 60 months to prevent bias. Primary outcomes were graft survival and rejection. Secondary outcomes were best spectacle-corrected visual acuity (BSCVA), detachment/rebubble, endothelial cell loss, and intraocular pressure elevations. Results: Baseline characteristics, follow-up duration, and preexisting glaucoma parameters did not differ significantly between the groups. Graft survival probability after DMEK and DSAEK was 75% and 75% at 1 year, 63% and 50% at 2 years, 49% and 44% at 3 years, 28% and 33% at 4 years, and 28% and 29% at 5 years, respectively (P = 0.899 between the groups). Graft rejection rates were 20.8% and 19.5%, respectively (P = 1.000). Primary failure, rebubbling, endothelial cell loss, and intraocular pressure elevation did not differ significantly between the groups. Preoperative BSCVA did not differ between the groups (P = 0.821). Postoperative BSCVA was significantly better in the DMEK group at 6, 12, and 24 months (P < 0.001, P = 0.022, and P = 0.047, respectively). In a multivariable model (R ² = 0.576), the type of surgery was the only significant factor affecting postoperative BSCVA, in favor of DMEK (coefficient value −0.518, P = 0.002). Conclusions: In eyes with previous glaucoma surgery, DMEK and DSAEK had comparably low survival and comparably high rejection rates. Postoperative visual acuity might be better after DMEK in this setting.

Purpose.To analyze the risk factors associated with a series of ectasia cases following photorefractive keratectomy (PRK) and all published cases.Methods.In a retrospective study on post-PRK ectasia patients, 9 eyes of 7 patients were included, in addition to 20 eyes of 13 patients from the literature. Risk of post-PRK ectasia was calculated using the ectasia risk score system (ERSS) for laser in situ keratomileusis (LASIK) patients. The percent tissue altered (PTA) was also evaluated.Results.ERSS scoring of zero for age, RSB, and spherical equivalent was found in 66%, 86%, and 86% of the eyes, respectively. Pachymetry risk score was 2 in 60% of the eyes and 3 or 4 in 16% of the eyes. Topography risk score was 3 in 41% of the eyes and 4 in 21% of the eyes. Cumulative ectasia risk score was ≥4 (high risk) in 77% of the eyes and ≥3 (medium and high risk) in 86% of the eyes. Average PTA was 23.2 ± 7.0%. All eyes but one had a PTA < 40%.Conclusions.Preoperative corneal topographic abnormalities and thin corneas may be significant risk factors for developing ectasia following PRK. Post-LASIK ectasia risk scoring also has relevance in the risk for developing post-PRK ectasia.