Benetz, Beth Ann

ABSTRACT Purpose Substantial endothelial cell loss (∼80%) occurs after keratoplasty. Corneal rigid and scleral lenses are frequently prescribed to manage irregular astigmatism and high refractive error, but lens wear may contribute to hypoxic stress. The relationship between various lens wear and corneal stress after penetrating keratoplasty remains unclear. This study characterizes cell density distribution in post‐keratoplasty corneas and evaluates its influence on swelling during lens wear. Methods Participants ≥5 years post‐surgery, with or without habitual lens wear, were enrolled. Specular microscopy measured endothelial cell density in central, superior, inferior, superotemporal, and superonasal corneal quadrants (@3 mm). Baseline corneal thickness maps (>2 h after waking without lens wear) were acquired using Scheimpflug imaging (Pentacam). Wearers applied habitual lenses and all participants returned 6–8 h later for imaging. Nonparametric tests assessed cell density variation by quadrant and lens designs. Linear mixed models evaluated associations between endothelial parameters and corneal swelling while accounting for within‐subject correlation, repeated measures, lens type, location, and interactions. Results Twenty‐five participants (31 eyes) from three centers were included; 90% had keratoconus preoperatively. Four wore large‐diameter scleral lenses (13%), nine wore small‐diameter scleral lenses (29%), 12 wore corneal rigid lenses (39%), and six did not wear lenses (19%). Cell density across quadrants averaged 780 ± 240 cells/mm 2 . Central thickness decreased slightly in non‐lens‐wearing eyes (−0.3%) but increased in lens‐wearing eyes (1.9% ± 3.1%). Central cell density showed a weak negative correlation with swelling ( r = −0.39, p = 0.03). Compared with non‐lens wearers, corneal rigid ( p = 0.02) and large diameter scleral lenses ( p = 0.05) generated greater swelling; smaller diameter scleral lenses did not. Conclusions Although all eyes fitted with various lens designs were clear, lower central cell density correlated with increased swelling during lens wear, except when smaller diameter scleral lenses were worn. Clinically, however, cell density does not seem to be a robust predictor of corneal swelling induced by lens wear post‐keratoplasty.

Importance If the success of Descemet membrane endothelial keratoplasty (DMEK) is not affected by whether the donor has diabetes, then the donor pool should expand. Objective To determine whether the 1-year DMEK success rate is affected by the presence of diabetes in the donor. Design, Setting, and Participants This was a multicenter, double-masked, randomized clinical trial conducted from February 2022 to July 2025 at 28 clinical sites (46 surgeons), with donor corneas provided by 13 eye banks in the US. Included in the study were individuals undergoing low to moderate risk DMEK (95% for Fuchs endothelial corneal dystrophy). Study data were analyzed from April to September 2025. Intervention DMEK performed with a cornea from a donor without or with diabetes, assigned using a minimization procedure (comparable with randomization) to achieve an approximate 2:1 distribution, respectively. Main Outcomes and Measures Graft success at 1 year Results A total of 1097 individuals (1421 study eyes; median [IQR] age, 71 [66-76] years; 631 female [57.5%]) were included in the study. The 1-year cumulative probability of graft success was 96.3% (95% CI, 95.0%-97.5%) among 912 study eyes (64.2%) receiving tissue from donors without diabetes and 97.1% (95% CI, 95.5%-98.4%) among 509 study eyes (35.8%) receiving tissue from donors with diabetes (difference between groups = 0.7 percentage points; 95% CI, −1.2 to 2.6; P = .63). The 1-year cumulative probability of graft success was 96.5% (95% CI, 93.6%-98.9%) in the mild donor diabetes severity subgroup (n = 173) and 97.3% (95% CI, 95.4%-98.8%) in the moderate to severe donor diabetes severity subgroup (n = 336), using a diabetes severity rating scale based on medical history. The rates of primary donor failure, early failure related to surgical complications, and subsequent failure were as follows: 2.5% (23 of 912), 0.7% (6 of 912), and 0.3% (3 of 912), respectively, in recipients of tissue from a donor without diabetes, and 2.6% (13 of 509), 0.4% (2 of 509), and 0%, respectively, among recipients of tissue from a donor with diabetes. There were no failures due to graft rejection. Conclusions and Relevance The 1-year success rate in eyes undergoing DMEK with successfully prepared tissue was very high regardless of donor diabetes status. These results, supported by the separately reported finding that endothelial cell loss and cornea morphometry after 1 year were not affected by donor diabetes status, provide strong support for having no restrictions on the use of tissue from donors with diabetes for DMEK. Trial Registration ClinicalTrials.gov Identifier: NCT05134480

Purpose: To evaluate agreement between eye banks (EBs) and a reading center on endothelial cell density (ECD) determinations in the Cornea Preservation Time Study. Methods: The Cornea Image Analysis Reading Center (CIARC) performed variable frame image analysis on EB-obtained–preoperative central endothelial images (after lamellar dissection for Descemet stripping automated endothelial keratoplasty by the EBs or before shipping, if surgeon prepared) to determine ECD. The EBs performed their usual method of ECD determination. The CIARC and EBs also provided ECD determinations from screening central endothelial images taken by the EBs during donor evaluation. Two independent masked CIARC readers determined ECD with measurements averaged. Results: The mean preoperative ECD was 15 cells/mm2 greater by the EBs than by CIARC (N = 1286, P < 0.001) with 95% limits of agreement of (−644, 675 cells/mm2). The limits of agreement in preoperative ECD were wider in the After-Lamellar-Dissection Group (−687, 683 cells/mm2) than in the Before Shipping Group [(−505, 633 cells/mm2); P = 0.03]. The EBs-determined preoperative ECD was within 10% of the CIARC-determined ECD for 886 (69%) image sets, with 236 (18%) higher by >10% and 164 (13%) lower by >10%. Excellent agreement appeared between the EBs and CIARC when 100–300 cells could be analyzed in contrast to <100 cells (SD = 308 cells/mm2 vs. SD = 603 cells/mm2; P < 0.001). Conclusions: The mean ECD by the EBs and CIARC were similar, but there was considerable variability between determinations for individual corneas. Agreement improved between the 2 measurements when more than 100 cells were able to be analyzed.