Comparative Effectiveness of Treatments for Open-Angle Glaucoma: A Systematic Review for the U.S. Preventive Services Task Force

Background: Glaucoma is an acquired degeneration of the optic nerve and a leading cause of blindness worldwide. Medical and surgical treatments that decrease intraocular pressure may prevent visual impairment and blindness. Purpose: To compare the effectiveness of medical, laser, and surgical treatments in adults with open-angle glaucoma with regard to decreasing intraocular pressure and preventing optic nerve damage, vision loss, and visual impairment. Data Sources: MEDLINE, CENTRAL, and an existing database for systematic reviews (through 2 March 2011); MEDLINE, EMBASE, LILACS, and CENTRAL for primary studies (through 30 July 2012). Study Selection: English-language systematic reviews; randomized, controlled trials; and quasi-randomized, controlled trials for most outcomes and observational studies for quality of life and harms. Data Extraction: Two investigators abstracted or checked information about study design, participants, and outcomes and assessed risk of bias and strength of evidence. Data Synthesis: High-level evidence suggests that medical, laser, and surgical treatments decrease intraocular pressure and that medical treatment and trabeculectomy reduce the risk for optic nerve damage and visual field loss compared with no treatment. The direct effect of treatments on visual impairment and the comparative efficacy of different treatments are not clear. Harms of medical treatment are primarily local (ocular redness, irritation); surgical treatment carries a small risk for more serious complications. Limitation: Heterogeneous outcome definitions and measurements among the included studies; exclusion of many treatment studies that did not stratify results by glaucoma type. Conclusion: Medical and surgical treatments for open-angle glaucoma lower intraocular pressure and reduce the risk for optic nerve damage over the short to medium term. Which treatments best prevent visual disability and improve patient-reported outcomes is unclear.