Second Ahmed valve insertion in the same eye.
OBJECTIVE
To examine the results of same-eye second Ahmed glaucoma drainage device (GDD) insertion in eyes with refractory glaucoma despite previous Ahmed GDD insertion and maximal tolerated medical therapy.


METHODS
Noncomparative retrospective case series.


RESULTS
Twenty-one patients who had undergone 2 GDD surgeries in the same eye were identified. Following chart review, 19 patients had follow-up of at least 1 year and were included in the analysis. All surgeries involved Ahmed valves. The mean drop in intraocular pressure (IOP) at 12 months and at final follow-up was 8 (43%) and 7.9 mm Hg (42%), respectively. The mean number of glaucoma medications used postoperatively (2.4 at 12 mo and 2.6 at final follow-up) was significantly less than preoperatively (4.1). Although the mean visual acuity was poorer postoperatively, this did not reach statistical significance. Sixteen of the 19 patients (84.2%) were defined as complete or partial success, as they achieved IOP of >/=5 and </=21 mm Hg and >/=20% decrease on preoperative IOP with or without glaucoma drops. Three patients were considered complete failures at 12 months and final follow-up. There were no significant intraoperative complications. One patient (5.3%) required anterior chamber reformation on day 1 postoperatively. One patient (5.3%) suffered a decrease in vision from 20/70 preoperatively to counting fingers postoperatively owing to corneal decompensation.


CONCLUSIONS
Second Ahmed GDD surgery seems to be a safe and effective option when IOP remains uncontrolled despite previous GDD implantation.
Department of Ophthalmology and Visual Sciences, Toronto Western Hospital, University of Toronto, Ontario, Canada. mic.smith@utoronto.ca
Michael
M
Smith
Yvonne M
YM
Buys
Graham E
GE
Trope
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D020327:Glaucoma Drainage Implants; D015812:Glaucoma, Angle-Closure / Q000503:physiopathology / Q000601:surgery*; D005902:Glaucoma, Open-Angle / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D007431:Intraoperative Complications; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D019919:Prosthesis Implantation; D012189:Retrospective Studies; D014065:Tonometry, Ocular; D016896:Treatment Outcome; D014792:Visual Acuity