Objectives: Glaucoma is a leading cause of visual impairment and blindness worldwide. Treatment focuses on the reduction of intraocular pressure (IOP), which secondarily prevents worsening of visual field loss; in this way, available treatments may prevent visual impairment and blindness. The objective of this Comparative Effectiveness Review is to summarize the evidence regarding the safety and effectiveness of medical, laser, and other surgical treatments for open-angle glaucoma in adults.
Data Sources: We searched MEDLINE®, Embase, LILACS, and CENTRAL through October 6, 2011 to identify clinical trials. We searched MEDLINE and CENTRAL (from 2009 to March 2, 2011) and screened an existing database to identify relevant systematic reviews.
Review Methods: Two reviewers independently assessed citations for eligibility. One reviewer assessed the risk of bias and extracted descriptions of the study. A second reviewer verified the data. Two reviewers also screened the results for systematic reviews. Details about the eligible systematic reviews were abstracted, including elements related to the methodological rigor.
Results: We identified 23 systematic reviews. Twelve reviews addressed medical treatments, 9 addressed surgical treatment, and 1 compared medical versus surgical treatments. One review addressed different surgical treatments as well as medical versus surgical treatments. We identified 73 RCTs and 13 observational studies addressing adverse effects. We identified no studies that evaluated treatments with regard to their impact on visual impairment. We also found insufficient evidence comparing treatment versus no treatment on patient-reported outcomes. No studies addressed the possible link between intermediate outcomes (IOP, optic nerve structure, or visual field) and visual impairment or patient-reported outcomes. There is moderate evidence that medical and surgical treatments can lower IOP and reduce the risk of progression by both visual field and optic nerve criteria. Among medical treatments, the prostaglandin agents are superior to other classes with regard to lowering IOP. While laser trabeculoplasty decreases IOP, the technology used does not make a difference in pressure lowering. With regard to incisional surgeries, trabeculectomy provides more pressure lowering than the class of nonpenetrating procedures. As expected, incisional surgeries produce more significant side effects than do medical treatments.
Conclusions: We did not find evidence addressing direct or indirect links between glaucoma treatment and visual impairment or patient-reported outcomes. This should be an area of focus in future trials of adequate size and duration to detect differences between treatment groups. However, we did find that a number of medical and surgical treatments clearly lower IOP and can prevent visual field loss and optic nerve damage. While we found direct comparisons between some treatments, there are significant gaps in our knowledge of comparative effectiveness.