Age-related macular degeneration is the leading cause of blindness in western nations, but vascular endothelial growth factor (VEGF) inhibiting drugs have revolutionized the treatment of retinal diseases, improving the lives of millions. However, these drugs have the potential to cause vascular side effects like stroke. New research done at the Institute for Clinical Evaluative Sciences (ICES) has found intravitreal injections of bevacizumab and ranibizumab (also known by their trade names Avastin and Lucentis) did not increase the risks of vascular events, such as heart attacks and strokes.
“These finding are highly significant because while we’ve seen explosive growth in the use of both drugs worldwide, our understanding of the safety risks is incomplete. Our results will help both physicians and policy makers in choosing the most appropriate therapy,” says Dr. Rob Campbell, scientist at ICES and an ophthalmologist at the School of Medicine at Queen’s University.
Intravenous administration of VEGF inhibitors for cancer has been associated with several adverse vascular events however, clinical trials have been inconclusive regarding the risks associated with the smaller doses injected directly into the eye to treat age-related macular degeneration.
The population-based, nested case-control study followed 91,378 older adults with a history of physician-diagnosed retinal disease between April 1, 2006 and March 31, 2011. Intravitreal injections of bevacizumab and ranibizumab were not associated with increased risks of ischaemic stroke, acute myocardial infarction, venous thromboembolism or congestive heart failure.
“Given what we know about how VEGF inhibitors act and the risks associated with their systemic use, valid concerns have been raised. We’ve looked at this issue in two studies with different methods and found consistent results. Our findings suggest that injections of small doses of these drugs into the eye are not associated with vascular events. There is still a need for ongoing surveillance and further research in specific groups at particularly high risk. Nevertheless, our results provide important information, and policy makers will need to look at all the available evidence to guide drug policies,” says Campbell.
The study “Adverse events with intravitreal injection of vascular endothelial growth factor inhibitors: nested case-control study,” is in the latest issue of the BMJ.
Authors: Robert J Campbell, Sudeep S Gill, Susan E Bronskill, J Michael Paterson, Marlo Whitehead, Chaim M Bell.
More detailed study findings on the ICES website.
ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of health care issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting health care needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.
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