Responsiveness of the National Eye Institute Visual Function Questionnaire to Changes in Visual Acuity: Findings in Patients Having Ranibizumab Treatment for Neovascular Age-Related Macular Degeneration

Abstract

Purpose: : To evaluate the visual function and it’s correlation to visual acuity in patients having ranibizumab treatment for neovascular age-related macular degeneration. The primary objective is to measure National Eye Institute (NEI) 25-item visual function questionnaire (VFQ-25) composite scores and Snellen visual acuity represented as a logMAR equivalent, both before treatment and after their third ranibizumab injection.

Methods: : A total of 60 consecutive cases awaiting intravitreal ranibizumab injection for neovascular age-related macular degeneration were recruited. The main outcome measures were interviewer administered National Eye Institute (NEI) 25-item visual function questionnaire (VFQ-25) composite scores and Snellen visual acuity represented as a logMAR equivalent, both before treatment and after their third Ranibizumab injection.Scores on their VFQ-25 were analyzed and converted to a 100-point scale in which 100 represents the best possible score and 0 represents the worst. Composite scores and LogMAR visual acuity were compared between pre- and post-injection and also analysis for correlation between logMAR visual acuity with NEI VFQ-25 composite scores was undertaken.

Results: : Mean baseline logMAR visual acuity was 0.81 and post-injection was 0.71, with 46% showing no change, 31% an improvement but only 23% showing a deterioration in vision. The mean VFQ-25 composite score at baseline was 61.7 and post-injection was 73.2, with a mean improvement of 11.5 (95% CI 3.0, 20.0) that was statistically significant (p=0.012).The correlation between the logMAR visual acuity and VFQ-25 composite score is very low (r=0.113) and not statistically significant (p=0.714) for pre-injection data and similarly for post-injection data which showed negative correlation (r= -0.185) but also not significant (p=0.544). This is an interim analysis and will be updated.

Conclusions: : Composite scores for VFQ-25 does not show a close correlation with logMAR visual acuity either pre- or post-ranibizumab injection. However, these composite scores show a significant improvement with ranibizumab injection. LogMAR visual acuity was stable or improved in 76%with ranibizumab injection.

Keywords: age-related macular degeneration