Abstract
Purpose :
Drivers with glaucomatous field loss are at greater risk for driving errors and motor vehicle crashes compared to age matched controls. This pilot study evaluated relationships between visual field loss and real-world driving in an instrumented vehicle (IV).
Methods :
In a prospective pilot study, 11 Glaucoma subjects with visual acuity≥20/40 in both eyes and 6 controls with normal visual acuity and no history of ocular disease were tested on a standardized drive across commercial, rural, and highway road sections in Omaha NE in the IV,VENUS (Vehicle for Ergonomics, Neuroscience, and Safety) .The IV drive video was evaluted by a certified occupational therapist and driving errors were annotated. Drivers in the IV performed a sign identification task (IT) including 73 restaurant and road signs along a 1.4 mile section of the route. Binocular visual field index (OU-VFI) and binocular superior VFI (S-VFI) and binocular inferior VFI (I-VFI) were calculated from monocular Humphrey visual fields (HVF) using previously described techniques. Cognitive ability was assessed using Montreal Cognitive Assessment [MoCA]. Spearman’s rank order correlation was used to determine association between variables.
Results :
11 Glaucoma subjects (6 males, age: 57 ± 15 years, MoCA score 26±3) were age matched with 6 controls (4males, age: 69± 5 years, MoCA score 27± 2). The mean OU VFI for the glaucoma subjects was 85 ± 14% (range 61 to 99%). The mean S-VFI was 80±23% and I-VFI was 89±11%. Driving errors in IV are enumerated in table 1. Glaucoma subjects made more driving errors than controls. Age and MoCA were not significantly associated with driving errors or performance on the LT task.
For the glaucoma subjects, driving errors were associated with OU-VFI (r=-0.6, p=0.07). I-VFI correlated better with number of driving errors (r= -0.7, p = 0.03) than did S-VFI (r = -0.5, p= 0.1) (Figure 1).
Glaucoma subjects identified fewer street signs than controls (table 1). The percentage of signs identified correlated with worsening OU-VFI (r=0.8, p=0.002), S-VFI (r=0.8, p=0.003) and I-VFI(r= 0.8, p = 0.007).
Conclusions :
Glaucoma subjects make more driving errors, particularly in lane maintenance, and have trouble identifying road signs compared to controls. Inferior field loss has greater influence on driving performance than superior field loss. Glaucoma subjects may benefit from customized driving rehabilitation therapy based on the region of their field loss.
This is a 2021 ARVO Annual Meeting abstract.