Viscocanalostomy versus trabeculectomy in white adults affected by open-angle glaucoma: a 2-year randomized, controlled trial☆
Presented in part at the Association for Research in Vision and Ophthalmology meeting, Fort Lauderdale, Florida, April 1999; and the American Academy of Ophthalmology Subspecialty Day, “Glaucoma 2000: Cutting Edge Diagnosis and Therapy,” Dallas, Texas, October 2000.
Received 6 August 2001; accepted 23 September 2002.
Abstract
Purpose
To compare the effectiveness and safety of viscocanalostomy and trabeculectomy in adults with uncontrolled open-angle glaucoma.
Design
Single-masked, parallel-group, prospective, randomized 24-month trial, with 90% power to detect a clinically important difference between groups.
Participants
Fifty consecutive patients (50 eyes) with primary open-angle or pseudoexfoliative glaucoma.
Intervention
Eyes were assigned randomly to either viscocanalostomy (group 1) or trabeculectomy (group 2) with no intraoperative antifibrotics in the study eye. In group 1, no further intervention was allowed, whereas trabeculectomy eyes could receive subconjunctival 5-fluorouracil (5-FU) injections or laser suture lysis after surgery.
Main outcome measures
Success rate based on intraocular pressure (IOP), visual acuity, discomfort, and other complications.
Results
At the end of the 24-month follow-up, IOP of 21 mmHg or less and more than 6 mmHg was achieved in 76% in group 1 (n = 19) and in 80% in group 2 (n = 20; log-rank P = 0.60); an IOP between 6 and 16 mmHg was obtained in 56% in group 1 (n = 14) and in 72% in group 2 (n = 18; log-rank P = 0.17; Kaplan-Meier cumulative probability of success). Complications of viscocanalostomy included one intraoperative conversion into trabeculectomy; microruptures in Descemet’s membrane in five eyes; three cases of iris incarceration in the Decemet’s window, two of which caused early failure of the procedure requiring reoperation; and a 1-mm to 2-mm transient self-resolving hyphema in three cases. Complications of trabeculectomy included one case of postoperative bleb bleeding with early transient IOP spike; one early hyphema; five cases of postoperative hypotony, two of which had a positive Seidel test from the conjunctival suture; three cases of transient choroidal detachment, two of which had shallow anterior chamber. No patient required reoperation. Two eyes required argon laser suture lysis, and nine underwent one or more 5-FU injections, which caused punctate keratopathy in three eyes.
Conclusions
Viscocanalostomy is an effective IOP-lowering procedure in white adults affected by open-angle glaucoma. Trabeculectomy with postoperative 5-FU can probably provides lower IOPs but, with more numerous complications, greater discomfort, and more intensive postoperative management.
1Department of Ophthalmology and Visual Sciences, University Hospital San Raffaele, Milan, Italy
Correspondence to Roberto G. Carassa, MD, Department of Ophthalmology and Visual Science, University Hospital San Raffaele, Via Olgettina 60, 20132 Milano, Italy.
ABSTRACT