Patients who receive repeated eye injections of the drug bevacizumab for age-related macular degeneration have an increased risk of subsequent glaucoma surgery, suggested results from a nested case-control study.
Among 74 patients who underwent glaucoma surgery and 740 control participants, the adjusted rate ratio for glaucoma surgery was more than doubled for patients who received seven or more intravitreous bevacizumab injections per year compared with those who received three or fewer (adjusted RR 2.48; 95% CI 1.25-4.93), reported , of the University of British Columbia, Vancouver, and colleagues.
On the flip side, patients who had glaucoma surgery were more likely to have received seven or more injections compared with nonsurgical controls, they wrote in .
"Clinicians and patients should be aware of the potential association between repeated, recent intravitreous anti-VEGF injections for diseases such as exudative age-related macular degeneration and the possibility of subsequent need for glaucoma surgery," Eadie told MedPage Today.
"Our study results emphasize the importance of carefully monitoring patients receiving repeated intravitreal anti-VEGF injections for sustained elevations in intraocular pressure or other signs of glaucoma," he continued.
Eadie and colleagues analyzed data from large, population-based health databases supported by the British Columbia Ministry of Health in Canada. All patients had ophthalmic issues in British Columbia and received intravitreous bevacizumab injections for exudative age-related macular degeneration from Jan. 1, 2009, to Dec. 31, 2013.
Cases were identified using glaucoma surgical codes for trabeculectomy, complicated trabeculectomy, glaucoma drainage device, and cycloablative procedure. Ten controls were identified for each case and matched for age, preexisting glaucoma, calendar time, and follow-up time. Injections were measured as three or fewer, four to six, or seven or more per year.
Rate ratios were approximated using a conditional logistic regression model and then adjusted for diabetes, myocardial infarction, stroke, and verteporfin use (Visudyne; Novartis and QLT PhotoTherapeutics).
Eadie's team identified a total of 74 cases of glaucoma surgery and 740 controls. Mean age was 81.3 years for cases and 81.4 years for controls and the case group had more males than the control group (51.4% versus 36.8%).
They found that more cases received seven or more intravitreous bevacizumab injections per year compared with controls (44.6% versus 34.3%; absolute increase, 10.3%).
Compared with those who received three or less intravitreous bevacizumab injections per year, there was no difference in the RR for cases versus controls who received four to six intravitreous bevacizumab injections per year (adjusted RR 1.65; 95% CI 0.84-3.23).
Eadie concluded that clinicians should be aware of the potential association of repeated, recent intravitreous injections with subsequent need for glaucoma surgery.
He wrote: "Our data will also lead to basic science aimed at investigating the pathogenesis of our observed association. In these ways, we hope that there will be a decreased need for glaucoma surgery in patients requiring this important treatment for retinal diseases in the future."
The researchers listed the large sample size, inclusion of only patients who received intravitreal bevacizumab injections for the indication of exudative AMD, and matching of preexisting glaucoma between cases and controls as study strengths.
Limitations included the inability to access details of individual disease severity and trajectory.
Disclosures
Etminan was a paid consultant in Mirena Propecia litigations. The authors reported no other financial disclosures of interest.
Primary Source
JAMA Ophthalmology
Eadie B, et al "Association of repeated intravitreous bevacizumab injections with risk for glaucoma surgery" JAMA Ophthal 2017; DOI: 10.1001/jamaophthalmol.2017.0059.