Corneal changes after a single session of selective laser trabeculoplasty for open-angle glaucoma

Purpose To investigate the changes in endothelial cell count, central corneal thickness (CCT), and refractive error after a session of selective laser trabeculoplasty (SLT) for open angle glaucoma (OAG). Methods This prospective cohort study recruited 111 eyes of 66 consecutive subjects with OAG. Subjects received SLT to 3601 of the trabecular meshwork. Endothelial cell count, CCT, and spherical equivalent were measured at baseline before SLT as well as at 1 week and 1 month post SLT. A repeated measure nested ANOVA with Tukey's multiple comparison test was performed to compare the outcome measures before and after SLT. Results In 111 eyes of 66 subjects, the mean number of laser applications per treatment was 166.9 +/- 41.4 with a mean energy level of 1.0 +/- 0.07 mJ. The mean endothelial cell count decreased significantly from 2465.0 +/- 334.0 cells/mm(2) at baseline to 2355.0 +/- 387.0 cells/mm(2) at 1 week (P = 0.0004) but increased to baseline levels at 1 month post SLT (2424.0 +/- 379.4 cells/mm(2), P = 0.3). The CCT, which decreased from a baseline of 549.4 +/- 37.6 to 543.9 +/- 40.2 mm at 1 week post SLT (P = 0.02), also returned to the baseline level by 1 month (P = 0.2). The spherical equivalent was static from baseline. A positive correlation was found between total laser energy and CCT at 1 month post treatment (r = 0.3, P = 0.005). Conclusion The transient reductions in endothelial cell count and CCT following SLT returned to baseline levels 1 month after the procedure. Patients undergoing SLT should be aware of the risk of potential corneal changes.