Baseline Predictors for Five-Year Visual Acuity Outcomes in the Comparison of AMD Treatment Trials

Abstract

Purpose: To determine baseline predictors of visual acuity (VA) outcomes at 5 years after initiating treatment with ranibizumab or bevacizumab for neovascular age-related macular degeneration (AMD).

Design: Secondary analysis of data from a cohort study.

Participants: Patients enrolled in the Comparison of AMD Treatments Trials (CATT) who completed a 5-year follow-up visit.

Methods: Participants were randomly assigned to ranibizumab or bevacizumab and to 1 of 3 dosing regimens. After two years, patients were released from the clinical trial protocol, and were recalled for examination at 5 years. Trained readers evaluated baseline lesion features, fluid and thickness. Baseline predictors were determined using univariate and multivariate regression analysis.

Main outcome measures: VA score and change from baseline, ≥3-line gain, and VA 20/200 or worse at 5 years.

Results: Among 647 patients with VA measured at 5 years, mean VA score in the study eye was 58.9 letters (≈20/63), mean decrease from baseline was 3.3 letters, 17.6% eyes gained ≥3 lines, and 19.9% had VA of 20/200 or worse. In multivariate analysis, worse baseline VA was associated with worse VA, more VA gain, higher percentage with ≥3-line gain, and higher percentage with 20/200 or worse at 5 years (all p<0.001). Larger baseline CNV lesion area was associated with worse VA, greater VA loss, and higher percentage with 20/200 or worse at 5 years (all p<0.05). Absence of baseline subretinal fluid was associated with worse VA (p=0.03) and more VA loss (p=0.03). Female gender, bevacizumab treatment in the first 2 years, and absence of RPE elevation were associated with higher percentage with ≥3-line gain. Cigarette smoking was associated with a higher percentage with 20/200 or worse. None of the 21 SNPs evaluated were associated with VA outcomes.

Conclusions: Five years after initiating treatment with ranibizumab or bevacizumab in CATT participants, worse baseline VA, larger baseline CNV lesion area, and presence of baseline RPE elevation remained independently associated with worse VA at 5 years. In addition, male gender, cigarette smoking, absence of subretinal fluid and treatment with ranibizumab in the first 2 years were independently associated with worse vision outcomes at 5 years.