Purpose
To describe the initial resolution of intraretinal fluid (IRF), subretinal fluid (SRF), or sub-retinal pigment epithelium (RPE) fluid (SRPEF) over time in eyes treated with ranibizumab or bevacizumab on an as needed basis (PRN) for neovascular age-related macular degeneration (AMD).
Methods
1185 CATT patients were randomly assigned to ranibizumab or bevacizumab and to monthly or PRN treatment. The 598 participants randomized to PRN treatment received treatment at baseline and re-treatment evaluation every 4 weeks based on lesion activity. Two certified Optical Coherence Tomography (OCT) Reading Center readers independently assessed the presence of IRF, SRF and SRPEF, with discrepancy adjudicated by a senior reader. Kaplan-Meier curves were used to estimate the cumulative proportion of participants with resolution of fluid over time (without consideration of recurrence of fluid).
Results
Among 591 participants with any OCT fluid at baseline, 477 (81%) had IRF, 490 (83%) had SRF, and 292 (49%) had SRPEF. Four weeks after the first injection, the proportion (95% confidence interval) of participants without fluid was 21% (18%, 25%) for any fluid, 38% (33%, 42%) for IRF, 49% (45%, 54%) for SRF, and 37% (32%, 43%) for SRPEF. By 3 months, the cumulative proportion resolved was 41% (37%, 45%) for any fluid, 65% (61%, 69%) for IRF, 72% (68%, 76%) for SRF, and 54% (49%, 60%) for SRPEF. During 2 years, participants treated with ranibizumab had fluid resolve more quickly than those treated with bevacizumab for any fluid (p=0.002), IRF (p<0.001), and SRF (p<0.001), but similar resolution rates for SRPEF for the two drug groups (p=0.50) (Table 1, Figure 1).
Conclusions
The majority of participants had resolution of fluid during the first year of treatment with ranibizumab or bevacizumab. IRF and SRF resolved quickly over the first several months of PRN treatment on both drugs, while SRPEF resolved more slowly. Ranibizumab was more effective than bevacizumab in resolving IRF and SRF, but the two drugs had a similar effect on SRPEF.