Predictors for the number of AMD injections

Orlando-Retinal angiomatous proliferation (RAP) lesions, treatment with ranibizumab, the absence of subretinal fluid, and the absence of subretinal pigment epithelium fluid (RPE) were associated with fewer injections for neovascular age-related macular degeneration (AMD) among participants from the Comparison of AMD Treatments Trials (CATT), said Daniel F. Martin, MD.

Dr. Martin, of the Cole Eye Institute, Cleveland Clinic, presented these results during a session on choroidal neovascularization (CNV) management at the 2014 meeting of the Association for Research in Vision and Ophthalmology.

The individuals studied had neovascular AMD and were randomly assigned to receive injections of ranibizumab or bevacizumab for 2 years as needed (PRN). Participants were scheduled for evaluation every 4 weeks. If the ophthalmologist observed fluid on optical coherence tomography (OCT) or had other signs of neovascular activity, the patient received an injection.

Researchers also collected demographic, CNV, OCT, and eye-specific information for each patient in the study.

Of the 598 patients who had PRN treatment, 501 (84%) survived through the 2-year trial period and had at least 20 out of a possible 26 opportunities for treatment, Dr. Martin said.

The mean number of injections was less with RAP lesions and no subretinal fluid (11.7 versus 13.9 for extrafoveal fluid and 13.4 for foveal fluid). Patients with RAP lesions had a mean of three fewer injections, Dr. Martin said.

Patients receiving ranibizumab had one less injection than the bevacizumab group.

Patients with no sub-RPE fluid were more likely to have eight or fewer injections-considered a low number of injections over the study period.

“It wasn’t the best predictor, but it was still statistically significant,” Dr. Martin said.

Researchers also invested if genetic factors or the use of beta blockers influenced the number of injections; neither seemed to have an effect, he said.

For more articles in this issue of Ophthalmology Times’ Conference Brief, click here.