Meta-analysis of Viscocanalostomy Versus Trabeculectomy in Uncontrolled Glaucoma

Purpose: Compare the efficacy and safety profile of viscocanalostomy versus trabeculectomy in uncontrolled glaucoma. Patients and Methods: We looked through various search engines for randomized controlled trials directly comparing viscocanalostomy with trabeculectomy. Outcome measurements we examined were mean intraocular pressure difference at 6 months, 12 months, and 24 months, mean difference in postoperative number of antiglaucomatous medications and relative risk of adverse events. Subgroup analysis looked at studies that included 1 eye per patient, studies that included only white patients, studies with only primary open angle glaucoma, studies that did not allow the use of intra-operative mitomycin C in trabeculectomy treatment, studies that did not allow any postoperative use of antimetabolites, and studies with and without the use of postviscocanalostomy Nd:YAG goniopuncture. Results: Ten randomized controlled trials were selected and included in the meta-analysis with a total of 458 eyes of 397 patients with medically uncontrolled glaucoma. At 6 months, mean intraocular pressure difference was 2.25 mm Hg (95% confidence interval 1.38-3.12), at 12 months it was 3.64 mm Hg (2.74, 4.54), whereas at 24 months it was 3.42 mm Hg (1.80, 5.03). Trabeculectomy was found to have a significantly better pressure-lowering outcome (P<0.0001). Relative risk of adverse events such as perforation of Descemet membrane, hypotony, hyphema, shallow anterior chamber, and cataract formation, were found to be 7.72 (2.37, 25.12), 0.29 (0.15, 0.58), 0.50 (0.30, 0.84), 0.19 (0.08, 0.45), and 0.31 (0.15, 0.64), respectively. Viscocanalostomy had a significantly higher relative risk of intraoperative perforation of Descemet membrane, whereas trabeculectomy had significantly more postoperative adverse events (P <= 0.008). Conclusions: Trabeculectomy was found to have a greater pressure-lowering effect compared with viscocanalostomy. However, viscocanalostomy had a significantly better risk profile.