MOTOR VEHICLE ACCIDENTS and GLAUCOMA

 

Glaucoma is a condition characterized by deterioration in the patient’s quality of life, relative to the progression of the disease. Some studies have reported that glaucoma patients are at increased risk of motor vehicle accidents (MVA).

A study has shown that drivers with severe binocular field loss, as determined by a screening test administered 40° nasally and 60° temporally at motor vehicle licensing offices, are approximately two times more likely to be involved in a crash than those with no field loss. [1]

There is a conventional notion in clinical practice that the eye with better function dictates visual performance. However, a study by McGwin et al. has shown that the worse eye’s visual field characteristics were significantly associated with crash involvement, whereas those of the better eye were not. [2]

The study evaluated the association between visual field defects in the central 24° field and the risk of MVAs among patients, 55 years or older, with glaucoma. The control set included glaucoma patients who were never involved in an MVA. 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.

Each eye was studied separately. When compared with individuals with no VF defects, in the case of the better-seeing eye of the patient having severe VF defects (scores 12-20) there was an increased risk of an MVA (odds ratio [OR] 3.2, 95% CI 0.9–10.4), although the association was not statistically significant. Moderate (6–11) or minor field defects (1–5) in the better eye were not associated with the risk of involvement in a crash.

However, when studying the worse eye of the patient, patients with moderate or severe field defects were at significantly increased risk of an MVA (OR 3.6, 95% CI 1.4–9.4 and OR 4.4, 95% CI 1.6–12.4, respectively) compared with those with no defects. However, minor field defects in the worse eye did not increase the risk of an MVA (OR 1.3, 95% CI 0.5–3.4).

The study concluded that patients with glaucoma who have moderate or severe visual field impairment in the central 24° radius field in the worse-functioning eye are at increased risk of involvement in a vehicle crash.

REFERENCE:

[1] Johnson CA, Keltner JL. Incidence of visual field loss in 20,000 eyes and its relationship to driving performance. Arch Ophthalmol. 1983;101:371–375.

[2] McGwin G Jr, Xie A, Mays A, Joiner W, DeCarlo DK, Hall TA, Owsley C. Visual field defects and the risk of motor vehicle collisions among patients with glaucoma. Invest Ophthalmol Vis Sci. 2005 Dec;46(12):4437-41. doi: 10.1167/iovs.05-0750. PMID: 16303931.