Intravitreal aflibercept effective in radiation retinopathy

Take-home message: Like bevacizumab and ranibizumab, aflibercept has been shown to be effective in treating radiation retinopathy. In a study, patients experienced improved visual acuity and resolution of cystoid macular edema.

By Laird Harrison

VIENNA, AUSTRIA - Intravitreal aflibercept can treat radiation retinopathy, even recalcitrant cases that have failed prior treatment, a researcher says.

“We found that patients with radiation retinopathy who received intravitreal aflibercept injections had overall improved visual acuity, even though it didn’t reach statistical significance,” Liliya Shevchenko, DO, of Retina Specialists of Michigan in Grand Rapids told Ophthalmology Times.

“There was a statistically significant improvement in central retinal thickness in patients with radiation-related cystoid macular edema who received intravitreal aflibercept injections,” she said.

Dr. Shevchenko presented the findings here at the American Society of Retina Specialists’ 2015 Annual Meeting.

The study, a case series, is the first to look at aflibercept in radiation retinopathy. Several other series have examined bevacizumab and ranibizumab for the same condition, and shown similar results, Dr. Shevchenko said.

Many patients who receive radiation treatment for tumors of the eye, orbit, paranasal sinuses, and cranial fossa develop radiation retinopathy, said Dr. Shevchenko. Among those treated for ocular melanoma, about 70% show signs of retinopathy within 2 years.

Radiation leads to retinal vascular occlusion and formation of microaneurysms, she said. Retinal ischemia from small vessel occlusion ultimately leads to macular edema, which is what aflibercept addresses.

To determine the efficacy of aflibercept in treating this condition, Dr. Shevchenko and her colleagues reviewed the charts of 24 patients, 22 with radiation retinopathy-related cystoid macular edema and two with radiation retinopathy-related anterior segment neovascularization.

Among patients with cystoid macular edema, there was a significant decrease in central retinal thickness from 427.66 µm to 309.14 µm (P = 0.001). These patients showed a trend toward improved visual acuity, from .75 logMAR to .69 logMAR, which did not reach statistical significance (P = 0.065.)

Anterior segment neovascularization temporarily regressed in the two patients with this neovascular glaucoma.

NEXT: Correlations between vision, tumors, distance, radiation plaque activity and more

The investigators looked for correlations between vision gained, tumor thickness, distance to the fovea, distance to the disc, radiation plaque activity, systemic conditions predisposing to vasculopathy, and time lapsed between diagnosis and treatment. But they did not find sufficient evidence to confirm any of these associations.

Still, they wondered if treating patients more quickly after diagnosis might improve the results.

“Not all the patients received treatment on day 1 of diagnosis of radiation retinopathy because aflibercept was not available,” said Dr. Shevchenko.

The researchers are continuing to follow these patients and adding to the sample. “We thought in the end that increasing the population size might be needed to prove statistical significance of the visual acuity improvement,” she said.

Not all the patients in this study underwent fluorescein angiography (FA) before and after the treatment, and she said thinks that studying this patient population with FA before and after treatment would be interesting.

Still, it’s not too early for clinicians to use this treatment in patients with radiation retinopathy, Dr. Shevchenko said.

“My recommendation would be to treat these patients because, overall, the trend was toward improved visual acuity and resolution of cystoid macular edema,” she said. “Therefore, I think a trial of aflibercept in this patient population would be reasonable.”

However, not every patient with radiation retinopathy is a good candidate for this treatment. “Obviously, there are some factors to consider,” she said, “such as the burden of frequent injections and whether there is severe ischemia noted on FA.”