Surgical Outcomes of Combined Trabeculectomy-Cyclodialysis for Glaucoma

Abstract

To determine the performance of combined trabeculectomy-cyclodialysis surgery over a 25-year period. A retrospective cohort study of 55 eyes (39 patients) treated between 1987 and 2012 was performed.The following data were collected: age, sex, glaucoma etiology, preoperative and postoperative number of topical medications, preoperative and postoperative laser trabeculoplasty, intraoperative and postoperative 5-fluorouracil application, lens status at the time of surgery, postoperative cataract surgery, duration of follow-up, and complications. Best-corrected LogMAR visual acuity was assessed preoperatively, at 1 year, and then at 2-yearly intervals for the duration of follow-up. Intraocular pressure (IOP) was assessed preoperatively and then at 1 week, 4 weeks, 1 year, and then at 2-yearly intervals for the duration of follow-up. Visual field indices were collected at baseline and at the completion of follow-up.Failure was defined as reoperation for glaucoma, progression to legal blindness, IOP≤5 mm Hg, >21 mm Hg, or <20% reduction below baseline. All others were a "complete success" if no additional topical medication was required and a "qualified success" if medication was required. Analyses using 18 and 15 mm Hg as upper limits for success were also performed. Mean IOP fell from 25.2 to 11.9 mm Hg over a mean 11.2 years. At completion of follow-up 32 eyes (58.2%) achieved an unqualified success, 18 (32.7%) a qualified success, and 5 (9.1%) a failure. No patient progressed to legal blindness. Cases with greater preoperative IOP had a greater reduction in IOP (P<0.0001). On univariate analysis no intraoperative application of antimetabolite (OR, 0.74; 95% CI, 0.49-0.94; P=0.022) and a longer follow-up (OR, 1.16; 95% CI, 1.02-1.33; P=0.025) predicted a higher final IOP; these were not significant on multivariate analysis. Thirty-six of 47 phakic eyes developed cataract; the majority occurred in the first 4 years. Combined trabeculectomy-cyclodialysis produces sustained lowering of IOP for long periods of time, despite a cataractogenic effect.