Revised Swedish visual field standards for a driver's licence: Threshold perimetry as a predictor of eligibility according to the current Swedish and current Norwegian suprathreshold standards.

Abstract

Purpose: To explore whether threshold perimetry can predict fulfilment of the current Swedish and current Norwegian Esterman perimetry standards for Group 1 driver's licence, and differences in compliance between the former and current Swedish visual field standards.

Methods: This study included perimetry examinations from individuals aged ≥18 years who underwent threshold perimetry (24-2 or 30-2) and binocular Esterman visual field testing on the same day during September 2010 to December 2022. Data were collected over 12 years from three Departments of Ophthalmology in Region Örebro County, Sweden. Threshold perimetry data were used to predict fulfilment of the current Swedish and current Norwegian Esterman visual field standards.

Results: In all, 798 individuals were included. Altogether (33%) failed the Swedish visual field standards for a Group 1 driver's licence in the past; by comparison, a significantly smaller proportion would have failed the current Swedish standards today, (18%) (p < 0.001; McNemar's test). Threshold perimetry, if all test points within the central 20° had values of ≥10 dB, could predict compliance with a sensitivity of 89% and 88% and a specificity of 73% and 78% for the current Swedish and current Norwegian Esterman standards, respectively.

Conclusion: Threshold perimetry may predict compliance with the current Swedish and current Norwegian Esterman visual field test standard for driving. A larger proportion of individuals may meet the current Swedish visual field standard for a Group 1 driver's licence compared with the former Swedish standard.