Abstract
Purpose: :
To evaluate the change in corneal endothelial cells after Ahmed glaucoma valve (AGV) implantation
Methods: :
We prospectively evaluated changes in density and shape of the corneal endothelium in 40 eyes (36 patients) those had undergone AGV implantation for the treatment of refractory glaucoma. The corneal specular microscopy was performed by non-contact specular microscope before surgery and 1, 6, 12, 18, 24 months after surgery. Evaluation was performed on the superior, superotemporal, superonasal and central area of the cornea in both eyes at each test. The changes at each time point were compared to the baseline and the control group, which consisted of 20 contralateral eyes of 20 subjects those had glaucoma and shown moderately controlled intraocular pressure with one or more of anti-glaucoma medications.
Results: :
The mean follow-up was 19.3 months (range, 9~24 months). There was a significant decrease in the average corneal endothelial cell count of the operated eye from baseline; 5.9% at 1 month, 11.0% at 6 months, 15.0% at 12 months, 16.3% at 18 months, and 18.3% at 24 months after surgery (p<0.05, Wilcoxon signed ranks test), while the control group showed no significant change (mean decrease of 2.8% at 12 months and 4.2% at 24 months on average). And the changes in endothelial cell count were significantly different between subject group and control group at all time points for 2 years after surgery. The supero-temporal area, the closest site from the tube opening, showed the greatest decrease in endothelial cell density (18.0% at 1 year and 22.6% at 2 years after surgery), while the central cornea showed the lowest decrease (12.0 at 1 year and 15.3% at 2 years). The morphological evaluation, by coefficient of variation in cell area and hexagonality, showed no statistically significant change during study period.
Conclusions: :
There was a statistically significant corneal endothelial cell loss in the operated eyes after AGV implant surgery, compared to the control eye, and the cell loss was increased over time, up to 18.3% on average at 2 years after surgery.
Keywords: cornea: endothelium • intraocular pressure