Glaucoma and On-Road Driving Performance
Sharon A. Haymes 1*,
Raymond P. LeBlanc 1,
Marcelo T. Nicolela 1,
Lorraine A. Chiasson 1,
and
Balwantray C. Chauhan 1
1 Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Canada
* To whom correspondence should be addressed. E-mail: sharon.haymes{at}dal.ca.
 |
Abstract |
|---|
PURPOSE: To investigate the on-road driving performance of glaucoma patients.
METHODS: The sample comprised 20 licensed glaucoma patients and 20 licensed subjects with normal vision, matched for age and gender. Driving performance was tested over a 10 km route incorporating 55 standardized maneuvers and skills through residential and business districts of Halifax, Canada. Testing was conducted by a professional driving instructor and assessed by an occupational therapist certified in driver rehabilitation, masked to participant group membership and level of vision. Main outcome measures were total number of satisfactory maneuvers/skills, overall rating, and incidence of at-fault critical interventions (application of the dual brake and/or steering override by the driving instructor to prevent a potentially unsafe maneuver). Measures of visual function included visual acuity, contrast sensitivity and visual fields (Humphrey Field Analyzer mean deviation [MD] and binocular Esterman points).
RESULTS: There was no significant difference between glaucoma patients (mean MD = -1.7 dB [SD, 2.2] and -6.5 dB [SD, 4.9], better and worse eye, respectively) and control subjects in total satisfactory maneuvers/skills (P = 0.65), or overall rating (P = 0.60). However, 12 (60%) glaucoma patients had one or more at-fault critical interventions compared to 4 (20%) control subjects (odds ratio = 6.00, 95%CI, 1.46-24.69; higher still after adjustment for age, gender, medications and driving exposure), the predominant reason being failure to see and yield to a pedestrian. For the glaucoma group, worse eye MD was associated with overall rating of driving (r = 0.66, P = 0.002).
CONCLUSIONS: This sample of glaucoma patients with slight to moderate visual field impairment performed many real-world driving maneuvers safely. However, they were 6 times as likely as normal vision subjects to have a driving instructor intervene for reasons suggesting difficulty with detection of peripheral obstacles/hazards and reaction to unexpected events.
Key Words:
glaucoma, visual field, driving, on-road
