Corneal Endothelial Cell Changes after Ahmed Valve and Molteno Glaucoma implants

PURPOSE: To evaluate the changes in corneal endothelial cell (CEC) indices in Ahmed valve and single-plate Molteno implants after 24 months of follow-up. SETTING: Imam Hossein Medical Center, Negah Eye Hospital and Vanak Eye Surgery Center, Tehran, IRAN METHODS: A historical cohort study was conducted. The records of patients who had Ahmed valve (n=29) or single-plate Molteno (n=28) implants and completed a 24-month period of the trial were reviewed and postoperative CEC indices were measured. Preoperative central CEC indices, performed for a then-ongoing trial, were compared with postoperative measurements of the last follow-up. The main outcome measure was endothelial cell count. RESULTS: There was no difference between the two operations in improving visual acuity and decreasing the number of anti-glaucoma medications required. However, Molteno group showed significantly better postoperative IOP control (P<0.001). There were 11.52% and 12.37% reduction in CEC density (cells/mm2) and 3.78 and 2.48 increase in CEC area (mm2) after 24 months in Ahmed valve and Molteno groups, respectively. There was no significant between-group difference in CEC density and area as well as corneal thickness, postoperatively. Both univariate and multivariate analyses did not show any significant difference between central CEC loss and patients’ pre- and postoperative factors. CONCLUSION: There were statistically significant quantitative (cell density) and minor qualitative (cell area) changes in central CEC parameters in both groups after 24 months of follow-up. Both groups appear to cause similar CEC damage after 2 years.