Preservation of corneal endothelium after pars plana tube insertion of the Ahmed glaucoma valve.

PURPOSE: To investigate surgical outcomes after pars plana implantation of the Ahmed glaucoma valve (ppAGV).

METHODS

The intraocular pressure, corneal endothelial damage and post-surgical complications of 31 consecutive refractory glaucoma eyes of 26 subjects who underwent ppAGV were prospectively studied at two centers.

RESULTS

Cell density (CD) at the central cornea decreased by 3.5 ± 15.0 and 10.2 ± 18.9% at 6 and 12 months, respectively. The CD loss at 1 year was comparable with the loss after cataract surgery alone (6.5 ± 8.5%, P = 0.441). Hexagonality (Hex) changed little, from 41.5 ± 15.6% at baseline to 41.8 ± 14.9% (P = 0.976) at 6 months and 41.6 ± 10.2% (P = 0.58) at 12 months. The coefficient of variation of the central corneal endothelium area (CV) changed from 40.7 ± 9.0% at baseline to 45.7 ± 12.6% (P = 0.078) at 6 months and 45.5 ± 11.2% (P = 0.013) at 12 months. Concomitant cataract surgery was a significant risk factor for CD loss. The probabilities of success or qualified success at 1 year were 66.1 and 83.6%, respectively. Most of the posterior segment complications, which were noted in 6 of 31 eyes (19%), were self-limiting, except for 2 eyes (6%) that developed retinal detachment as a consequence of kissing choroidal detachment.

CONCLUSIONS

Corneal endothelial damage was minimal, and the success probability was relatively high after ppAGV in refractive glaucoma cases.