Abstract
Purpose :
The effect of missed appointments for anti-VEGF treatment for age-related macular degeneration(AMD) on visual acuity(VA) is unknown. We performed a secondary analysis of the Comparison of Age-Related Macular Degeneration Treatment Trial(CATT) study to evaluate the association between patient’s visit adherence to clinical trial visits and VA in AMD patients.
Methods :
The publicly available CATT data files were reviewed to characterize visit adherence. The 2-year CATT study protocol required a visit every 4 weeks(every 28-35 days, 26 total). Visit adherence was measured in 4 ways: average number of days(avg days) between each visit, longest duration in days between visits, total number of missed visits, and visit constancy (the tally of 3-month periods with at least 1 visit attended). Average and maximum days between visits were also categorized as being “on time”(28-35 days), “late”(36-60 days), and “very late”(>60 days). The primary outcome was change in ETDRS visual acuity (VA) between the baseline study visit and the last visit. Nonparametric univariate tests, linear and multivariate regression models were applied to analyze the association between visit adherence parameters and change in VA, controlling for age, gender, and baseline VA.
Results :
1,173 CATT patients had complete visit data. Mean(standard deviation [SD]) number of missed visits was 2.7(±3.7). 1,088(93%) patients had complete visit constancy over the length of the study period. Avg days between visits were 38.2[SD±31.8] days; when categorized, 966(82.3%) patients were classified as “on time,” 125 (10.7%) were “late,” and 82 (7.0%) were “very late.” These groups averaged +3.0, -1.1, and -0.9 letter change in vision, respectively. The longest duration between two visits ranged from 29 to 667 days (84.8[±118.6] days).
Increasing number of missed visits and longest duration between visits were significantly associated with decreasing final visual acuity(p<0.02 for both). Patients whose average visit interval were "late" and "very late" were also more likely to have worse vision(p<0.001). This remained true even after controlling for baseline vision, gender and age in multivariate regression modeling. Visit constancy and avg days between visits were not associated with VA.
Conclusions :
Visit adherence can contribute to visual acuity outcomes in AMD.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.