A study recently published in JAMA and presented at the American Academy of Ophthalmology annual meeting showed that treating proliferative diabetic retinopathy (PDR) patients with injections of the anti-VEGF agent ranibizumab had a non-inferiority (not worse than) outcome of visual acuity change after two years compared with the PRP group. Understanding that PRP often damages the retina, researchers with the Writing Committee for the Diabetic Retinopathy Clinical Research Network conducted a study of 394 eyes with PDR to explore less damaging treatment options. 

	This patient with proliferative diabetic retinopathy had a hemoglobin A1c of 9%. Photo: Carlo J. Pelino, OD, and Joseph J. Pizzimenti, OD.

Individual eyes were randomly assigned PRP treatment, completed in one to three visits, or treatment with ranibizumab by intravitreous injection at study entry and as frequently as every four weeks. The mean visual acuity letter improvement at two years was +2.8 in the ranibizumab group vs. +0.2 in the PRP group, meeting the study’s predetermined noninferiority outcome.

In addition to comparable visual acuity outcomes, they found more peripheral visual field loss occurred, more vitrectomies were performed and diabetic macular edema (DME) development was more frequent in the PRP group compared with the ranibizumab group, resulting in those participants also receiving ranibizumab to treat DME. 

“This article confirmed many of our clinical experiences,” says Nate Lighthizer, OD, assistant professor and assistant dean of Clinical Care Services at Oklahoma College of Optometry. “With these results, perhaps treating ophthalmologists and referring optometrists have decisions to make on which procedure to perform and refer for.”

“The follow-up was only for approximately two years, so longer follow-up studies are needed,” he adds. “This study represents, however, a groundbreaking finding that may change the protocol for treating PDR.”  

Gross JG, Glassman AR, Jampol LM, et al. Writing Committee for the Diabetic Retinopathy Clinical Research Network. Panretinal photocoagulation vs intravitreous ranibizumab for proliferative diabetic retinopathy: A randomized clinical trial. JAMA. 2015 Nov 13:1-11. [Epub ahead of print].