Effect of prophylactic laser iridotomy on corneal endothelial cell density over 3 years in primary angle closure suspects

Objective To assess the effect of prophylactic laser peripheral iridotomy (LPI) on corneal endothelial cell density (ECD) and morphology in primary angle closure suspects (PACS) over 3 years. Methods In this prospective cohort study, subjects underwent LPI in one eye, while the fellow eye was untreated. Specular microscopy was performed at baseline and after 1 and 3 years. Central corneal ECD and morphology of both eyes were assessed using noncontact specular microscopy (Konan SP-9000LC, Konan Inc, Hyogo, Japan). Results 230 subjects completed 3-year follow-up. The mean age was 62.5±8.0 years, and the majority of subjects were Chinese (92.3%) and women (75.4%). In eyes that underwent LPI, ECD was significantly lower at year 1 (2462.3, 95% CI 2414.5 to 2510.0, p<0.0001) and year 3 (2510.6, 95% CI 2462.1 to 2559.2, p=0.0006) compared with baseline (2609.1, 95% CI 2551.4 to 2666.7). There was also a significant decrease in ECD in fellow untreated eyes from baseline to year 1 (p<0.0001) and year 3 ( p=0.01). The decrease in ECD at 3 years compared with the baseline in treated and untreated eyes was similar (2.1% vs 0.9%, p=0.20). Conclusions In PACS eyes, there was decrease in ECD in LPI-treated and control eyes over 3 years, with no significant difference between groups.