Association of Baseline Characteristics and Early Vision Response with 2-Year Vision Outcomes in the Comparison of AMD Treatments Trials (CATT)

Abstract

To evaluate the association of baseline characteristics and early visual acuity (VA) response with visual outcomes at years 1 or 2 in the Comparison of Age-Related Macular Degeneration (AMD) Treatments Trials (CATT). Secondary analysis of CATT. The 1185 CATT participants with baseline VA of 20/25 to 20/320. Participants were assigned to ranibizumab or bevacizumab and to 1 of 3 dosing regimens. Associations of baseline characteristics and early VA response (week 4 or 12) with VA response at years 1 or 2 were assessed by R(2) from linear regression analyses. Patients who had a poor initial response (VA 20/40 or worse with persistent fluid and without ≥1-line VA gain) were defined as candidates for changing treatment. Visual acuity change from baseline. Statistically significant (P < 0.05) baseline predictors for less VA gain at year 2 were older age, VA of 20/40 or better, larger choroidal neovascularization area, presence of geographic atrophy, total foveal thickness ≤325 μm or ≥425 μm, and elevation of retinal pigment epithelium. Among 176 eyes gaining ≥3 lines at week 12, 78% had a ≥3-line gain at year 2, whereas among 113 eyes losing ≥1 line at week 12, 27% improved to a ≥1-line gain at year 2. Visual acuity response at week 12 was more predictive of VA response at year 2 (R(2) = 0.30) than VA response at week 4 (R(2) = 0.17) and baseline predictors (R(2) = 0.13; P < 0.0001). Among 126 candidates for changing treatment drug at week 12, mean VA improved by 2.8 letters (P = 0.050), mean total retinal thickness decreased 53 μm (P < 0.0001), and fluid resolved in 33% (P < 0.0001) between week 12 and year 1 with continued use of the same drug and regimen. Similar improvements were observed among 83 candidates for changing drugs at week 24. Visual acuity response at week 12 is more predictive of 2-year vision outcomes than either several baseline characteristics or week 4 response. Eyes with poor initial response may benefit from continued treatment without switching to another drug.