APR 25, 2017
Using data from the Canadian Health Ministry, investigators found that 7 or more intravitreal injections per year may cause an increased risk of uncontrolled glaucoma.
The findings emphasize that even procedures that appear relatively benign can bear a risk to the patient. In addition, to minimize risk, physicians should keep in mind that treat-and-extend protocols may be preferable over routine injections at fixed intervals.
In this cohort, the authors sorted patients who had received bevacizumab injections for AMD, identifying 74 patients who subsequently required glaucoma surgery (trabeculectomy, glaucoma drainage device or cycloablative procedure). The definition did not include laser trabeculoplasty, MIGS, or combined cataract and glaucoma surgery. Controls included 740 patients matched for age, preexisting glaucoma, calendar time and follow-up time.
Patients who received 7 or more injections per year had a 2.48-fold higher rate of glaucoma surgery compared with controls. Patients receiving 4 to 6 injections per year had a 65% higher glaucoma surgery rate compared with those receiving 3 or fewer injections, but the difference did not reach statistical significance. The study parallels other recent investigations showing a high rate of ocular hypertension and glaucoma among patients receiving repeated intravitreal injections.
While multiple previous studies have linked repeated intravitreous injections to IOP elevation, the mechanism remains unclear. Nevertheless, clinicians should be aware of this potential risk associated with anti-VEGF therapy and should carefully monitor patients for sustained elevations in IOP or other signs of glaucoma.