The Assessment of Driving Skills in the Presence of Restricted Visual Fields Associated with Retinitis Pigmentosa

Neryla Jolly DOBA(T), MA (Mac)

The vision standard required by the Roads and Traffic Authority in New South Wales until mid-1997 stated that a driver must have 6/12 visual acuity in the better eye and a peripheral visual field of 130 degrees on the horizontal plane using a standard perimeter with a 3mm target at 1/3 metre.
Three case studies are presented which demonstrate that, in the presence of field loss which fails to meet that standard but matches or exceeds the standard when a larger target is used, the driving skills reflect the standard with the larger target. Assessment of driving performance in the on-road situation is described with reference to the performance of the individual drivers. Remedial strategies are also described.
The outcome for these drivers demonstrates that the visual standard as laid down by the licensing authorities should be used to alert practitioners to the existence of a vision defect and then to refer an affected patient for assessment in the driving situation. The driver’s performance can then be evaluated in a realistic setting and where appropriate remediation instigated to achieve a safe driving standard.