Viscocanalostomy versus trabeculectomy in white adults affected by open-angle glaucoma: a 2-year randomized, controlled trial.

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.