Purpose: To identify the effects of anti-angiogenic therapy in neovascular age-related macular degeneration (AMD) in respect to morphologic type and time course and to identify prognostic factors for visual outcome on the basis of standardized optical coherence tomography (OCT) analysis.
Design: Subanalysis of a prospective, 12-month, multicenter, phase IIIb trial (Efficacy and Safety of Ranibizumab in Patients with Subfoveal Choroidal Neovascularization Secondary to Age-Related Macular Degeneration [EXCITE]).
Participants: A total of 353 treatment-naïve patients with subfoveal choroidal neovascularization (CNV) receiving quarterly or monthly ranibizumab therapy.
Methods: Patients were randomized to receive 0.3 mg quarterly, 0.5 mg quarterly, or 0.3 mg monthly doses of ranibizumab. Treatment comprised a loading phase of 3 consecutive monthly injections followed by a 9-month maintenance phase of monthly or quarterly injections. Best-corrected visual acuity (BCVA) was measured using the Early Treatment Diabetic Retinopathy Study protocol, and retinal morphology was assessed by Stratus OCT (Carl Zeiss Meditec, Dublin, CA). Imaging data were evaluated by certified examiners of the Vienna Reading Center using a standardized protocol.
Main outcome measures: The BCVA was measured using ETDRS charts and retinal morphology was assessed by OCT.
Results: During the loading phase, there was a significant correlation between a reduction in central retinal thickness and an increase in BCVA (P < 0.001), which decreased during the maintenance phase in all treatment arms. The proportion of patients showing retinal morphologic changes, such as intraretinal cysts (IRCs), subretinal fluid (SRF), and pigment epithelial detachments (PEDs), decreased significantly in all groups (P < 0.001), more intensively in the 0.5 mg quarterly than in both 0.3 mg groups. Intraretinal cysts resolved most rapidly followed by SRF, whereas PED decreased at a slower rate and intensity. Patients with IRC at baseline had lower BCVA levels that remained lower over the entire study period, whereas recurrence of IRC during follow-up showed no additional negative effect on function. Baseline SRF had no effect on visual recovery; however, recurrence of SRF during follow-up showed a tendency for an additional negative effect on function (P = 0.06). Baseline PED showed a negative influence on visual outcome only in combination with IRC and SRF.
Conclusions: There is a distinct response pattern and time course of morphologic parameters associated with anti-vascular endothelial growth factor therapy in neovascular AMD. Specific alterations, such as IRC, SRF, and PED, as baseline or follow-up features are significantly influencing the potential for visual gain.
Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.