Abstract
Purpose :
To assess correlation between change in best-corrected visual acuity (BCVA) and change in central subfield thickness (CST) for diabetic macular edema receiving fixed-dosing intravitreal aflibercept injection (IAI) over 100 weeks.
Methods :
Post hoc analysis of VISTA and VIVID wherein eyes were randomized to IAI 2 mg q 4 weeks (2q4) or IAI 2 mg q8 weeks after 5 initial monthly doses (2q8). The relationship between change in functional (BCVA) and change in anatomical (CST) outcomes at early (week 12) and later (week 52, and 100) visits was determined using Pearson correlation.
Results :
Of 872 eyes, 290 were treated with 2q4 and 286 with 2q8. Percentage of eyes with BCVA and CST measurements available for analysis at weeks 12, 52, and 100 was 95%, 86%, and 74% in the 2q4 arm; and 97%, 85%, and 71% in the 2q8 arm. At baseline, the correlation (r) between CST and BCVA was -0.45 (95% CI: -0.53, -0.35) and -0.47 (95% CI: -0.55, -0.37) in the 2q4 and 2q8 arms. Change in CST and change in BCVA at weeks 12, 52, and 100 had r values of -0.39 (95% CI: -0.49, -0.29), -0.27 (95% CI: -0.38, -0.15), and -0.30 (95% CI: -0.41, -0.17) in the 2q4 arm and -0.28 (95% CI: -0.39, -0.17), -0.29 (95% CI: -0.41, -0.17), and -0.33 (95% CI: -0.44, -0.20) in the 2q8 arm. Linear regression analysis of correlation between changes in CST and changes in BCVA at week 100, adjusted for relevant factors showed CST changes accounted for 17% of variance in BCVA changes; every 100 μm decrease in CST was associated with a 1.2 letter increase in BCVA (P = .001).
Conclusions :
Correlations between change in CST and change in BCVA following 2q4 or 2q8 fixed-dosing regimens of IAI for DME were modest. For any given change in CST from baseline, there was a broad range of change in BCVA from baseline at follow-up. These findings are consistent with a PRN regimen in the DRCR Retina Network Protocol T and suggest change in CST may be important in determining the need to withhold, continue, or resume anti-VEGF therapy for DME, but is a poor surrogate for predicting visual acuity outcome, even with fixed-dosing treatment regimens.
This is a 2021 ARVO Annual Meeting abstract.