Abstract
Purpose:
Conjunctival scarring represents a major risk factor for trabeculectomy failure. The purpose of this study was to compare the 3-year clinical outcomes of glaucoma drainage device (GDD) surgery in glaucomatous eyes with and without prior conjunctival incisional surgery.
Methods:
A retrospective chart review was conducted to identify glaucoma patients that had undergone Baerveldt™ GDD surgery (350 mm2) for uncontrolled intraocular pressure (IOP) from 2006 to 2010. All eyes had a minimum of 6 months of postoperative follow-up. Eyes were categorized as primary tube (PT) or prior scarring (PS) based upon the presence or absence of prior conjunctival incisional surgery. Failure was defined as IOP > 21 mmHg or not reduced by 20% below baseline on two consecutive follow-up visits after 3 months, reoperation for glaucoma, or loss of light perception vision. Success rates were evaluated using Kaplan-Meier survival analysis.
Results:
Eighty-four eyes from 83 patients were enrolled including 41eyes in the PT group and 43 eyes in the PS group. Eyes with PS had at least one prior surgical procedure consisting of trabeculectomy (n=30), penetrating keratoplasty (n=7), pars plana vitrectomy (n=7), and scleral buckle (n=4). Mean baseline age (years) in PT (72±15) and PS (70±12) groups were similar (p=0.55). Mean baseline IOP (mmHg) and medication use in PT eyes (27.6±9.9 and 3.6±0.97) were significantly greater (p=0.04 and 0.03) compared to PS eyes (23.4±8.8 and 3.1±1.2). At 3 years, IOP (mean ± SD) was 14.5±4.3 in the PT group and 13.9±4.1 in the PS group (p=0.70), and the number of glaucoma medications (1.93±1.4 and 2.32±1.5) was similar (p=0.45). The cumulative probability of failure during the first 3 years of follow-up was 47% in the PT group and 39% in the PS group (p = 0.48, Log Rank test). The rate of reoperation for glaucoma was 31% and 22% (p=0.21, Log Rank test) in the PT and PS groups, respectively.
Conclusions:
Glaucomatous eyes with and without prior conjunctival scarring have similar failure rates after GDD surgery. Both groups had similar IOP reduction and use of supplemental medical therapy at 3 years.