Corneal epithelial defects following micropulse transscleral cyclophotocoagulation: incidence, clinical course and associated ocular phenotypes

Background/Aims To estimate the frequency and clinical course of corneal epithelial defects after micropulse transscleral cyclophotocoagulation (MPCPC) and identify associated risk factors in eyes with refractory glaucoma. Methods This single-centre retrospective cohort study included adults undergoing index MPCPC between January 2023 and July 2024. One eye of each patient was randomly selected when both eyes were eligible. The primary outcome was a documented corneal epithelial defect within 90 days of MPCPC. Persistent defects were defined as lasting ≥14 days. Associations with candidate risk factors were evaluated using logistic regression. Results Among 187 eyes from 187 patients, 16 developed an epithelial defect within 90 days (8.6%; 95% CI 5.0% to 13.5%). Median time to detection was 11 days (IQR 1–22) and median time from detection to documented healing was 16 days (IQR 6.8–20.8). 10 defects (62.5%) persisted for ≥14 days, 11 (68.8%) involved the visual axis and 10 (62.5%) were followed by corneal scarring. Defects were more frequent in neovascular glaucoma (NVG) than non-NVG eyes (10/34 (29.4%) vs 6/153 (3.9%); p<0.001). In multivariable Firth logistic regression, NVG (adjusted OR 13.72; 95% CI 3.39 to 68.73) and prior corneal epitheliopathy or punctate epithelial erosions (adjusted OR 7.77; 95% CI 2.12 to 35.74) remained associated with epithelial defects. Conclusion Corneal epithelial defects were documented in 8.6% of eyes after MPCPC. NVG and pre-existing corneal epitheliopathy were significant risk factors. Many were persistent or followed by corneal scarring, supporting closer postoperative corneal surveillance in high-risk eyes.