The researchers conducted a literature search of MEDLINE and Embase, PubMed, Cochrane Library, and Web of Sciences databases from 2003 to 2023.
A recent study published in Journal of Glaucoma suggests that driving can be negatively impacted by glaucomatous visual field defects, ultimately resulting in poorer driving performances and higher rates of motor vehicle collisions. The researchers conducted a literature search of MEDLINE and Embase, PubMed, Cochrane Library, and Web of Sciences databases from 2003 to 2023 and concluded that more severe glaucomatous visual field and bilateral glaucoma is associated with poor driving performance in both simulator and real-world settings.
The study’s first author is Zhi Hong Toh, MMBS (S’pore), MMed (Ophth), FRCOphth, of the National Healthcare Group Eye Institute, Tan Tock Seng Hospital in Singapore.
“Glaucoma negatively impacts other visual functions other than VF testing, including depth perception, contrast sensitivity and glare,” the study authors stated. “While not within the scope of this review, these other aspects of visual impairment are likely to affect driving performance as well. Patients with glaucoma often suffer from glare, which may worsen with disease progression. Self-reported glare resulting in driving modifications has been shown to be associated with increased risk of driving difficulty in poor driving conditions in some studies, although not in others. Poorer contrast sensitivity and dark adaptation also appears to affect glaucoma patients, leading them to limit or give up driving completely. While the majority of studies included in this review did not measure aspects of visual function apart from VF defects, of note, the studies which did[find] that VF deficits impacted driving performance and increased incidence of driving cessation and MVCs, even after accounting for these other aspects of visual impairment.”
The database search for the review ultimately yielded 835 studies by searching the following terms:
Twenty studies were selected, with 3 more studies being included through hand-searching.
Of the studies selected, 10 studied the impact of glaucomatous visual field defects on driving performance. In examining these particular studies, patients with more advanced glaucoma and more significant visual field defects demonstrated poorer driving performance compared with patients without glaucoma in studies that utilized driving simulators. Additionally, patients with glaucoma often faced more challenges with lane maintenance and maintain lateral vehicle position compared with controls in simulated driving conditions. Poor driving performances of glaucoma patients have also been demonstrated in real-world cases. Other studies found that patients with more advanced glaucoma and a greater extent of visual field loss were more likely to limit or cease driving compared to patients with less severe glaucoma.
Nine of the 23 studies included in the review examined the impact of glaucomatous visual field loss on the frequency of vehicle collisions; under both simulator and real-world conditions, those with glaucoma or with a greater severity of glaucomatous visual field loss demonstrated a higher incidence of collision. Additionally, older patients with glaucoma have been shown to have significantly longer reactions times when performing secondary tactile response tasks and reaching and grabbing tasks, which are also necessary when driving.
“Various glaucomatous VF defects have been described. It has been commonly understood that glaucomatous VF defects usually extend from the physiological blind spot, following the horizontal raphe and later resulting in a partial arcuate defect. The defect eventually involves central fixation and the entire hemifield. Recent evidence, however, suggests central VF damage occurring in earlier stages of the disease. The involvement of central fixation with macular involvement affects the central VA in these patients,” the authors stated.
Researchers cited limitations of the review being that there was an insufficient pool of studies to pull from to generate pooled outcome measures, with the included studies being “relatively heterogeneous.” “The included studies were also mostly observational in nature, with no blinding, which could bias outcome measures and affect internal validity,” the authors stated. “Nevertheless, these studies provided useful information regarding the effect of glaucomatous VF defects on driving and hence were included in this review.”
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