Purpose
To describe baseline patient-reported visual function for a cohort entering an 18 month interventional trial and their association with best-corrected visual acuity (BCVA) and geographic atrophy (GA) lesion size.
Methods
BAM114341 is a randomized, double-masked, placebo-controlled study to investigate the safety, tolerability, efficacy of GSK933776 in adults with GA secondary to AMD. In the first phase, 191 subjects with GA were enrolled and followed for 4-months without intervention in order to establish baseline growth rates. NEI-VFQ-25 questionnaire was administered at screening and at the 4-month visit. NEI-VFQ-25 responses were scored following standard algorithms on 0-100 scales where lower scores indicate worse function. Scores at screening were analyzed by an ANOVA grouped by BCVA (>20/40, 20/40-20/80,<20/80) and by GA area (quartiles). Changes over the observation period were analyzed by a t-test.
Results
Average age and lesion area at screening were 77.2 (SD=8.6) years and 7.7 (SD=4.6) mm2, respectively. Average BCVA was 62.7 (SD=14.8) letters. Mean NEI-VFQ-25 scores at screening (Figure 1a) were consistent with historical data of AMD (Suner IJ et al. IOVS. 2009;50:3629) and displayed a relationship with declining BCVA and enlarged GA area. While stratified by BCVA, the most significant decrements in composite and 6 subscale scores occurred between the >20/40 and 20/40-20/80 subgroups (Figure 1a). For GA area, the most significant decrements in the scores for the composite and 9 subscales occurred between Q2 and Q3 (Figure 1b). A small but statistically significant decrease in composite score [-1.5, 95% CI (-2.7, -0.2)] was observed over 4 months.
Conclusions
Subjects with GA experience significant impairment in many aspects of visual function. The decrement in function is more pronounced during early vision loss, and as GA size crosses the median value (6.6 mm2). This suggests a need for early intervention in this population. Further research is needed to identify the characteristics of patients with rapid decline in visual function.