Surgical Results of Ahmed Glaucoma Valve Implantation in One-chamber Eyes

Ahmed glaucoma valve (AGV) implantation in eyes with damaged iris-lens diaphragms ("1-chamber" eyes) resulted in mean intraocular pressure (IOP) and antiglaucoma medications decreases of 66% and 59% (P<0.0001 for both), respectively, at the mean 23-month follow-up.

The purpose of this study was to report the results of AGV implantation with pars plana tube insertion to control IOP in glaucomatous eyes with damaged iris-lens diaphragms ("1-chamber" eyes).

The medical records of 52 consecutive glaucomatous 1-chamber eyes (48 Japanese patients, mean age±SD, 76.0±11.2 y) were retrospectively reviewed. Other than aphakic eyes, eyes were defined as having 1 chamber if intraocular lenses (IOLs) were sclerally or intrasclerally fixated, IOLs were fixed on-the-bag due to posterior capsular defects, vitreous collapse into the anterior chamber resulted from Zinn zonular dialysis, and phacodonesis or IOL-donesis required lens/IOL explantation during AGV implantation. The data collected were preoperative/postoperative IOPs, numbers of antiglaucoma medications, visual acuity, anterior chamber flare, visual field mean deviation, corneal endothelial cell density, and surgical complications/interventions.

The preoperative IOP (28.5±9.4 mm Hg) and a number of antiglaucoma medications (3.2±1.2) decreased significantly (P<0.0001 for both) to 9.8±3.3 mm Hg and 1.3±1.3, respectively, at the final visit (mean follow-up, 23 mo). The success rates of IOP control (6 to 21 mm Hg and >20% reduction irrespective of medication use) were 82.5% and 79.0%, respectively, at postoperative years 1 and 2. The most common postoperative complications were macular edema (n=9, 17%), choroidal detachment (n=8, 15%), vitreous hemorrhage (n=7, 13%), and hyphema (n=7, 13%). The most common postoperative intervention was tubal repositioning/reopening (n=6, 12%). Compared with preoperative values, the visual acuity, anterior chamber flare, mean deviation, corneal endothelial cell density remained unchanged postoperatively.

Choice of pars plana AGV tube insertion with simultaneous vitrectomy is reasonable to achieve IOP reduction and minimize vision-threatening complication in glaucomatous eyes with a damaged iris-lens diaphragm.