Effect of ranibizumab retreatment frequency on neurosensory retinal volume in neovascular amd.

Purpose: To determine the characteristics of patients with neovascular age-related macular degeneration who show initial anatomic improvements on optical coherence tomography in response to treatment with ranibizumab, but who subsequently regress toward their anatomic baseline. Methods: Data from 50 consecutive patients, receiving ranibizumab therapy for neovascular age-related macular degeneration, were collected. Raw StratusOCT images were analyzed using custom software ("OCTOR"). Changes in volume of neurosensory retina at months 1, 3, and 6 were calculated. Baseline demographic and morphologic characteristics were compared. Results: Forty-two patients (84%) showed a reduction in total retinal volume 1 month after initial treatment with ranibizumab. Of the patients that initially showed a reduction, 16 (38%) maintained this reduction through month 6, whereas 26 patients (62%) demonstrated a subsequent increase in retinal volume. Patients who maintained a reduction in edema received 3.75 +/- 1.18 injections of ranibizumab versus 2.96 +/- 1.34 injections for patients who did not (P = 0.049). Regression of initial anatomic improvements was associated with worsening of visual acuity (r = 0.599, P = 0.002). Conclusion: Patients receiving fewer injections of ranibizumab appeared less likely to maintain anatomic improvements achieved following commencement of ranibizumab therapy; regression of these improvements was associated with deterioration in visual acuity. RETINA 29:592-600, 2009