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 between primary open angle glaucoma (POAG) and pseudo-exfoliation glaucoma (PEX) after Ex-Press (EXP) surgery. Patients and Methods: This was a single-facility retrospective study. We included patients who had undergone EXP surgery and were followed up > 3 years. We measured the CED before and after EXP surgery by noncontact specular microscopy. We measured the CED at baseline and 12, 24, and 36 months post-surgery 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: POAG group, n = 60 eyes; PEX group, n = 59 eyes. In the POAG group, the mean CED decreased from 2389 ± 321 at baseline to 2230 ± 424 cells/mm ² after 3 years. In the PEX group, the mean CED decreased from 2111 ± 510 at baseline to 1845 ± 628 cells/mm ² after 3 years. After 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 Compared to POAG, EXP surgery for PEX patients decreased their corneal endothelial cells faster.