Patients with age-related macular degeneration who received seven or more eye injections of the drug bevacizumab annually had a higher risk of having glaucoma surgery, according to a Canadian study.
The advent of intra-vitreous (in the vitreous, the fluid behind the lens in the eye) anti-vascular endothelial growth factor (VEGF) injections to treat common causes of vision loss, such as exudative (wet) age-related macular degeneration (AMD) and diabetic macular edema has improved visual outcomes for many patients.
Intra-vitreous injections of anti-VEGF agents may increase the risk of elevated intraocular pressure (IOP); however, the risk of developing moderate to advanced glaucoma requiring glaucoma surgery has been unclear.
Dr Brennan D Eadie, of the University of British Columbia, Vancouver, and colleagues conducted a study that included patients who had received intra-vitreous bevacizumab injections for exudative age-related macular degeneration. Cases were identified using glaucoma surgical codes for various procedures. For each case, 10 controls were identified; the number of intra-vitreous bevacizumab injections received per year was determined for both cases and controls.
Seventy-four cases of glaucoma surgery and 740 controls were identified. The researchers found that seven or more injections were associated with a significantly higher risk of glaucoma surgery.
"Clinicians should be aware of the potential association of repeated, recent intra-vitreous anti-VEGF injections for diseases, such as exudative AMD, with subsequent need for glaucoma surgery," the authors write.
Abstract
Importance: Intravitreous injections of anti–vascular endothelial growth factor (VEGF) agents are associated with a sustained increase in intraocular pressure. This sustained elevated intraocular pressure could lead to higher rates of glaucoma surgery to lower this pressure.
Objective: To determine the risk of glaucoma surgery following repeated intravitreous bevacizumab injections.
Design, Setting, Participants: This nested, case-control study acquired and analyzed data from large, population-based, linked health databases supported by the British Columbia Ministry of Health in Canada. Study participants included all patients with ophthalmic issues in British Columbia, such as those of the Provincial Retinal Diseases Treatment Program, who had received intravitreous bevacizumab injections for exudative age-related macular degeneration between January 1, 2009, and December 31, 2013. Cases were identified using glaucoma surgical codes for trabeculectomy, complicated trabeculectomy, glaucoma drainage device, and cycloablative procedure. For each case, 10 controls were identified and matched for age, preexisting glaucoma, calendar time, and follow-up time. The number of intravitreous bevacizumab injections received per year—3 or fewer, 4 to 6, or 7 or more—was determined for both cases and controls. Data analysis was performed from February 23, 2016, to November 14, 2016.
Main Outcomes and Measures: Risk of glaucoma surgery compared with the number of intravitreous bevacizumab injections per year in cases and controls. Rate ratios were adjusted for covariates (diabetes mellitus, myocardial infarction, stroke, and verteporfin use).
Results: Seventy-four cases of glaucoma surgery and 740 controls were identified, with a mean (SD) age of 81.3 (8.4) years for cases and 81.4 (7.9) for controls. The case group had more males than the control group (38 [51.4%] vs 272 [36.8%]). The adjusted rate ratio of glaucoma surgery among those who received 7 or more injections per year was 2.48 (95% CI, 1.25-4.93). There was a 10.3% higher number of 7 or more injections among cases compared with controls. The adjusted rate ratio for those who received 4 to 6 injections per year compared with those who received 3 or fewer was 1.65% (95% CI, 0.84-3.23).
Conclusions and Relevance: Findings from this large, pharmacoepidemiologic study suggest that 7 or more intravitreous injections of bevacizumab annually is associated with a higher risk of glaucoma surgery and that 4 to 6 injections per year show a nonstatistically significant rate ratio in the same direction.
Authors
Brennan D Eadie, Mahyar Etminan, Bruce C Carleton, David A Maberley, Frederick S Mikelberg
[link url="https://www.sciencedaily.com/releases/2017/03/170316141026.htm"]JAMA material[/link]
[link url="http://jamanetwork.com/journals/jamaophthalmology/article-abstract/2612193"]JAMA Ophthalmology abstract[/link]