Abstract
Purpose :
Clinical trials such as Protocol T have led to intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy as a first line treatment for eyes with vision-impairing center-involved diabetic macular edema (CI-DME). However, visual outcomes and need for further anti-VEGF treatment after completion of the clinical trials, when follow up and retreatment regimens are managed in standard care, are less well established.
Methods :
In Protocol T, participants (N=660) with vision-impairing center-involved diabetic macular edema (CI-DME) were randomized 1:1:1 to aflibercept, bevacizumab, or ranibizumab with protocol defined visits and retreatments for 2 years, after which follow-up and treatment were performed at clinician discretion. At 5 years (3 years after Protocol T completion) eligible participants were recruited for a follow-up visit. Data on clinical visits and treatments occurring between 2 and 5 years were collected retrospectively. Five-year visual acuity (VA) and central subfield thickness (CST) outcomes were assessed with linear models that adjusted for baseline measures where appropriate.
Results :
Sixty-eight percent (N=317/463) of eligible participants completed the 5-year follow-up. The median number of visits between 2 and 5 years was 12 (interquartile range [IQR]: 5, 21) with 68% receiving at least one anti-VEGF injection (Median: 4; IQR: 0, 12). Mean VA at 5-years was +7.4 (95% Confidence Interval [CI]: +5.9, +9.0) letters higher than baseline but -4.7 (95% CI: -3.3, -6.0) letters lower than 2-years. Stratified by baseline VA subgroups, mean VA at 5 years was +11.9 (95% CI: +9.3, +14.5) and +3.2 (95% CI: +1.4, +5.0) letters higher than baseline but -4.8 (95% CI: -2.5, -7.0) and -4.6 (95% CI: -3.1, -6.1) letters lower than 2-years for participants with baseline VA Snellen equivalents of 20/50 - 20/320 and 20/32 - 20/40, respectively. Mean CST at 5 years was -154 (95% CI: -142, -166) microns thinner than baseline and only -1 (95% CI: -12, +9) micron thinner than 2-years.
Conclusions :
At the 5-year visit, mean VA and CST improved relative to baseline. However, after participants no longer followed protocol defined treatment criteria, mean VA decreased while mean CST remained stable. Strategies to improve long-term visual outcomes among eyes with DME are still needed.
This is a 2020 ARVO Annual Meeting abstract.