Purpose
To describe the association of baseline features and drug on the number of injections administered through 2 years to eyes with neovascular age-related macular degeneration that were treated on an as needed basis (PRN) with either ranibizumab or bevacizumab.
Methods
Participants in the Comparison of AMD Treatments Trials (CATT) were randomly assigned to ranibizumab or bevacizumab and scheduled for treatment evaluation every 28 days. Eyes were treated if the examining ophthalmologist observed fluid on OCT or other signs of neovascular activity. Baseline patient demographic and health features and ocular characteristics centrally graded from color photography, fluorescein angiography, and optical coherence tomography (OCT) were investigated for their association with mean number of injections and the proportion of eyes with a low number (≤8) of injections within 2 years. Regression models using backward selection were fit to estimate adjusted means (linear regression) and adjusted odds ratios (ORs, logistic regression) and their 95% confidence intervals (CIs).
Results
Among the 598 patients assigned to PRN treatment, 501 (84%) lived through 2 years, had at least 20 out of a possible 26 opportunities for treatment, and were included for analysis. The mean number of injections (Table 1) was less with retinal angiomatous proliferation (RAP) lesions (10.6 vs 13.7; p=0.001), no subretinal fluid (11.7 vs 13.9 for extrafoveal fluid and 13.4 for foveal fluid; p=0.04), no sub-RPE fluid (11.5 vs 13.9 for extrafoveal fluid and 15.6 for fovea fluid; p<0.001), and treatment with ranibizumab (12.4 vs 14.3 for bevacizumab; p=0.002). Eyes with foveal sub-RPE fluid (OR 0.33 CI [0.20, 0.55]) or extrafoveal fluid (OR 0.58 CI [0.34, 0.99]) were less likely to have ≤8 injections than those with no sub-RPE fluid (Table 2; p<0.001).
Conclusions
Baseline predictors of a lower number of injections include RAP lesion, treatment with ranibizumab, absence of subretinal fluid, and absence of sub-RPE fluid.
Keywords: 412 age-related macular degeneration •
466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials