Visual Field Defects and the Risk of Motor Vehicle Collisions Among Patients with Glaucoma

Abstract

This study sought to evaluate the association between visual field defects in the central 24° field and motor vehicle collisions (MVC) among patients with glaucoma. A case-control study was conducted on glaucoma patients aged 55 and older being treated at three university-affiliated eye care practices. Cases were patients who sustained a police-reported motor vehicle collision (MVC); controls were those who did not experience a MVC. For each patient, an Advanced Glaucoma Intervention Study (AGIS) score was calculated on automated visual fields collected with the 24-2 or 30-2 programs. Additionally, demographic, behavioral, driving and clinical characteristics were obtained via chart abstractions and a patient telephone survey. With respect to the better eye AGIS score (defined according to AGIS score), compared to patients with no visual field defect, those with severe defects (scores 12-20) had an increased risk of MVC (odds ratio [OR] 3.2, 95% confidence interval [CI] 0.9-10.4), although this association was not statistically significant (p=0.0576). Moderate (6-11) or minor field defects (1-5) in the better eye were not associated with the risk of crash involvement. For the worse eye, patients with moderate and severe field defects were at significantly increased risk of a MVC (OR 3.6, 95% CI 1.4-9.4 and OR 4.4, 95% CI 1.6-12.4 respectively) compared to those with no defects. Minor field defects in the worse eye did not increase MVC risk (OR 1.3, 95% CI 0.5-3.4). Glaucoma patients with moderate or severe visual field impairment in the central 24° radius field in the worse functioning eye are at increased risk for involvement in a vehicle crash.