Purpose
To evaluate the effects of Ahmed glaucoma valve implants on corneal decompensation and corneal endothelial cell density (ECD) changes in refractory glaucoma patients.
Methods
Seventy-nine patients (79 eyes) who had undergone Ahmed glaucoma valve implantation for treatment of refractory glaucoma more than 5 years previously were consecutively enrolled. ECD was examined longitudinally using a noncontact specular microscope. Corneal decompensation, defined as corneal edema resulting from failure of the corneal endothelium to maintain deturgescence, was subjected to a Kaplan-Meier survival analysis. In a subgroup of 53 patients evaluated by at least four serial corneal specular microscopy examinations at intervals of 6 months postoperatively, the rate of progressive decrease in ECD was determined by linear regression and compared with that of the control group, which consisted of 26 contralateral glaucomatous eyes receiving antiglaucoma medication without glaucoma surgery. The demographics were compared between the patients with corneal decompensation and those without it. The relevant demographic factors and the ECD changes were then subjected to a correlation analysis.
Results
The mean follow-up was 5.6 years. Of the enrolled 79 patients, corneal decompensation occurred in five. The corneal decompensation survival rate was 95.7% at 2 years, and 88% at 9 years. The number of previous intraocular surgeries for these 5 patients was significantly higher than that of the other 74 patients (3.4 vs. 0.7, P=0.007). In the 53-patient subgroup, the postoperative ECD change rate was 5.0% per year, which, compared with the rate for the 26-eye control group (0.3%, P<0.001), was statistically significant. An association of the postoperative rate of ECD change with the number of past intraocular surgeries was evident (P=0.048).
Conclusions
Corneal decompensation occurred after Ahmed glaucoma valve implantation in 12% of patients at 9 years. There was a statistically significant progressive ECD loss on the operated eye. The number of past intraocular surgeries is associated with corneal decompensation and the rate of ECD change after Ahmed glaucoma valve implant surgery.
Keywords: 462 clinical (human) or epidemiologic studies: outcomes/complications •
482 cornea: epithelium