Drivers with visual field loss in one Australian licensing jurisdiction
Keywords: Older Drivers/Users
Submission Date: 2007
In Australia, the presence of a visual field deficit condition requires assessment by an optometrist or ophthalmologist before an individual can be considered fit-to-drive. However, there are currently limitations in the validity of tests and criteria used for assessing vision for safe driving. This paper examines the scope of the problem in one Australian jurisdiction by identifying the prevalence of visual field loss (VFL) amongst drivers referred for medical review and describing the current practices for managing their licence review. A random sample of medical review cases was extracted from the VicRoads Medical Review database to identify cases involving VFL conditions: glaucoma, age-related macular degeneration, diabetic retinopathy, hemianopia/ quadrantanopia and retinitis pigmentosa. Data on demographic information, visual field loss conditions and the referral process were collected for all identified cases.
A total of 170 cases (2.0% of 8295 total medical review cases) with visual field deficits were identified. Of these, 23 (14.7%) were involved in crashes and referred to VicRoads on this basis. Of these cases, 124 (72.9%) were assessed by either an optometrist or ophthalmologist. The most commonly used ophthalmological tools for assessing field loss included the Humphrey Field Analyzer (n=42, 26%); Esterman (n=16, 10%) and Goldman (n=7, 4%) visual field tests. In 89 (55%) cases, licences were continued unconditionally, 42 (26%) were discontinued, 14 (9%) were made conditional, and in 18 (11%) the decision was pending further review.
Drivers with visual field loss tended to be older and the majority had co-morbid conditions. There was considerable variation in the methods for assessing visual deficits. Despite the Austroads Fitness to Drive recommendations, 27.1% of cases were not referred for further assessment by an optometrist or ophthalmologist. Though some of these drivers may have surrendered their licences or had them discontinued on the basis of other reasons, 22 (13.9%) of these drivers had their private car licences continued and one driver had a commercial licence continued on a conditional basis without specialist vision assessment. Five cases had their private licences discontinued based on static perimetry alone. In two of these five cases, the drivers were contesting the decision made by VicRoads. These findings are discussed in the context of the current medical review guidelines in Australia.