Visit Adherence and Visual Acuity in Study of COmparative Treatments for REtinal Vein Occlusion 2 (SCORE2)

Purpose: We quantify the association between visit adherence and visual acuity (VA) in retinal vein occlusions (CRVO). Methods: The SCORE2 protocol included a visit every 4 weeks (every 28–35 days) during the first year. Visit adherence was measured as follows: number of missed visits, average and longest (avg and max days) visit interval, and average and longest (avg and max missed days) and unintended visit interval. Avg and max missed days were categorized as on time (0 days), late (>0–60 days), and very late (>60 days). The primary outcome was a change in the Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity letter score (VALS) between baseline study visit and last attended visit during Year 1, using multivariate linear regression models controlling for numerous demographic and clinical factors. Results: After adjustment, for each visit missed, patients lost 3.0 letters (95% CI: −6.2, 0.2) of vision (p =.07). On average, the 48 patients who missed at least 1 visit lost 9.4 letters (95% CI: −14.4, −4.3, p <.001) of vision after adjustment. Average days and maximal intervals between visits were not associated with changes in VALS (p >.22) for both comparisons. However, when a visit was missed, the average missed days between missed visits and the max missed interval were both associated with loss of VALS (both variables: 0 days missed as reference, late [1–60 days] −10.8 letters [95% CI: −16.9, −4.7], very late [>60 days] −7.3 letters [95% CI: −14.5, −0.2]; p =.003 for both). Conclusions: Visit adherence is associated with VALS outcomes in CRVO patients.