Driving and Visual Acuity in Patients with Age-Related Macular Degeneration

Abstract

Purpose: To assess driving status, habitual visual acuity (VA) in the better-seeing eye, and self-reported driving difficulty among patients diagnosed with age-related macular degeneration (AMD).

Design: Cross-sectional cohort study of 553 AMD patients' habitual VA, self-reported driving status, and driving difficulty at time of interview.

Participants: Patients diagnosed with AMD and recruited into the University of Colorado registry.

Methods: Measurement of habitual VA by median logarithm of the minimum angle of resolution (logMAR) and Snellen equivalent, as well as 3 categories: 20/40 or better, 20/50 or 20/60, and worse than 20/60. Driving difficulty was self-reported on the 25-item National Eye Institute Visual Function Questionnaire.

Main outcome measures: Self-reported driving status and driving difficulty.

Results: A total of 394 patients (71.2%) reported currently driving at time of study interview. Drivers were significantly younger than nondrivers (mean age, 76.7 years vs. 83.9 years; P < 0.0001) and were more likely to be men (42.6% vs. 25.8%; P = 0.0002). Median habitual VA in the better-seeing eye was better among drivers: 0.097 logMAR (Snellen equivalent, 20/25) versus 0.301 logMAR (Snellen equivalent, 20/40) for nondrivers (P < 0.0001). Among drivers, habitual VA was 20/40 or better for 87.6% of patients, 20/50 to 20/60 for 9.6% of participants, and worse than 20/60 for 2.8% of participants. Driving patients with habitual VA in the better-seeing eye of 20/40 or better reported less difficulty driving compared with patients with 20/50 or worse VA.

Conclusions: In our study, most patients with AMD who were currently driving had at least 20/40 VA in the better-seeing eye. However, 12.4% of patients had VA of 20/50 or worse and reported more difficulties with driving. As the aging population continues to grow with increasing lifespan, the number of patients with AMD will increase, and discussion of driving and VA will become more clinically and legally pertinent.