Purpose: To assess the intraocular pressure-lowering efficacy and the postoperative complication profile of viscocanalostomy versus trabeculectomy.
Patients and methods: Sixty eyes of 60 patients with medically uncontrolled open-angle glaucoma were randomized either to the viscocanalostomy or to the trabeculectomy group of the trial. Viscocanalostomy was performed according to Stegmann's technique using high-molecular-weight sodium hyaluronate to fill the ostia of the Schlemm canal. For trabeculectomy, a modified Cairns-trabeculectomy was performed. Examinations were performed before surgery and postoperatively daily for 1 week. Follow-up visits were scheduled 1, 6, and 12 months after surgery.
Results: The mean (SD) preoperative intraocular pressure was 27.1 (7.1) mm Hg for all patients enrolled. One day after surgery, mean (SD) intraocular pressure was 15.9 (5.2) for the trabeculectomy group (P <0.001) and 15.7 (3.6) for the viscocanalostomy group (P <0.001), respectively. The success rate, defined as an intraocular pressure lower than 22 mm Hg without medication, was 56.7% in the trabeculectomy group and 30% in the viscocanalostomy group at 12 months postoperatively (P = 0.041). The number of postoperative complications was lower in the viscocanalostomy group than in the trabeculectomy group.
Conclusions: In eyes with open-angle glaucoma, viscocanalostomy is less effective in reducing intraocular pressure than standard filtering surgery. However, postoperative complications are more frequent after filtering surgery.