Visual field assessment and the Austroad driving standard

Purpose: To compare the conventional (Humphrey 24-2) automated visual field testing with the Goldmann standard visual field test for driving, and to predict how many patients with glaucoma may not meet the Australian driving standard with respect to visual fields. Methods: Four patients (retinitis pigmentosa, glaucoma or vigabatrin treatment) with marked visual field defects as determined by uniocular static computerized perimetry (conventional testing) were re-evaluated with binocular kinetic Goldmann IV4e target field test (Australian driving standard). A series of 48 consecutive patients seen by the Glaucoma Inheritance Study in Tasmania were assessed with both static computerized perimetry and the Goldmann IV4e target test. Results: The four patients with severe visual field defects (on computerized perimetry) were found to meet the driving standard on the binocular Goldmann IV4e target test. On computerized perimetry, 15 of 48 patients from the Glaucoma Inheritance Study in Tasmania were found to have visual field defects of sufficient severity that they may not meet the driving standard. However, only five of these patients failed the driving standard for visual fields, two of whom were still driving. Conclusions: Patients with severe field defects on conventional uniocular automated perimetry may still meet the Goldmann standard visual field test for driving. Approximately 30% of glaucoma patients would have visual field loss shown on Humphrey 24-2 test of a severity that requires further testing to determine if they meet the driving standard. Ten per cent of glaucoma patients tested did not meet the driving standard for visual fields.