Rishi Singh, MD, talks about the prevention of macular edema in patients with diabetic retinopathy undergoing cataract surgery with an intravitreal aflibercept injection.
Rishi Singh, MD: We treat a lot of diabetic patients and 1 of the most significant reasons for vision loss in a diabetic eye is diabetic macular edema. The other big complication in diabetic eyes is cataract surgery and cataract progression over time, and so the way we learn as clinicians how to manage these 2 together is what we did in the PROMISE study.
The PROMISE study was undertaken to determine how we manage diabetic macular edema, which occurs sometimes after cataract surgery in these patients, and how best to educate our colleagues on how best to manage these sort of complications. The purpose of the study was really to evaluate the use of an anti-VEGF agent at the time of cataract surgery versus patients who received a sham injection to determine if they had a better clinical outcome both from vision and OCT and other parameters we looked at. The study basically found a significant number of patients developed macular edema following surgery. In the sham arm, about 50% of patients developed macular edema, if you lose a couple different criteria definitions for that, and for those patients in the aflibercept arm, the rates were much, much lower, in the 10% to 14% range.
Now, if you look at that a little bit differently as far as macular edema goes, by the thickness of the OCT that number drops to about 30% in the sham arm, but only about 1% in the aflibercept-treated group patients in that study. So we did see anatomical benefits, and probably the one that I think is the most important benefit of this study was those patients were 20/20 following surgery, and in those groups, a significantly higher percentage of patients in the aflibercept arm were 20/20 or better following surgery versus those in the sham-treated groups.
When we talk about cataract surgery patients we always want to achieve that 20/20 outcome and this drug definitely helped achieve that in the phase 2 study. The phase 3 will be important to power that study to show that differential both in visual acuity and anatomy following the cataract surgery. And again, it could lead to an approval of this drug in a fashion for patients to prevent macular edema following cataract surgery, and those that the highest risk of that condition, which is those patients who have diabetic retinopathy at baseline.