Primary viscocanalostomy versus trabeculectomy for primary open-angle glaucoma: three-year prospective randomized clinical trial.

Objective: To compare the efficacy and safety of viscocanalostomy and trabeculectomy in patients with primary open-angle glaucoma (POAG).

Methods: Department of Ophthalmology, Ankara Education and Research Hospital, Ankara, Turkey. Methods: In this prospective randomized trial, 50 eyes of 50 patients with medically uncontrolled POAG were randomized to have a trabeculectomy (25 eyes) or a viscocanalostomy (25 eyes). Visual acuity, intraocular pressure (IOP), and slitlamp examinations were performed before surgery and 1 day, 1 week, 1, 3, and 6 months, and 1, 2, and 3 years postoperatively.

Results: At 3 years, the mean IOP was 16.0 mmHg +/- 7.07 (SD) in the trabeculectomy group and 17.8 +/- 4.6 mmHg in the viscocanalostomy group (P=.694). Complete success (IOP 6 to 21 mm Hg without medication) was achieved in 66.2% of eyes at 6 months and 55.1% at 3 years in the trabeculectomy group and in 52.9% and 35.3%, respectively, in the viscocanalostomy group (P>.05). Qualified success (IOP 6 to 21 mmHg with medication) was achieved in 95.8% of eyes at 6 months and 79.2% at 3 years in the trabeculectomy group and in 90.7% and 73.9%, respectively, in the viscocanalostomy group (P>.05). Postoperative hypotony and cataract formation occurred more frequently in the trabeculectomy group than in the viscocanalostomy group (P=.002).

Conclusions: Primary trabeculectomy lowered IOP more than viscocanalostomy in POAG patients. However, the complication rate was lower in the viscocanalostomy group.