Comparison of corneal endothelial cell density reduction between primary open-angle glaucoma and pseudo-exfoliation glaucoma patients at 3 years after Ex-Press® surgery

Purpose: We compared corneal endothelial cell (CED) loss after Ex-Press (EXP) surgery between patients with primary open-angle glaucoma (POAG) and pseudo-exfoliation glaucoma (PEX). Patients and methods: This was a single-facility retrospective study. We included glaucoma patients who had undergone EXP surgery and were followed up > 3 years. We measured the CED before and after (at 12, 24, and 36 months) EXP surgery by noncontact specular microscopy and compared the means of the CED values and CED survival ratios after EXP surgery by paired t-test. Results: We included 119 eyes that underwent EXP surgery, including 60 POAG eyes and 59 PEX eyes. In the POAG group, the mean CED decreased from 2389 ± 321 at baseline to 2230 ± 424 cells/mm² after 3 years. In the PEX group, the mean CED decreased from 2111 ± 510 at baseline to 1845 ± 628 cells/mm² after 3 years. At the 3-year follow-up, the CED survival ratio was 93.3 ± 12.5% in the POAG group and significantly lower, at 85.0 ± 19.5%, in the PEX group (p = 0.0064). Two cases in the PEX group developed bullous keratopathy. Conclusions: EXP surgery decreased the corneal endothelial cell populations in PEX patients faster than POAG patients.