Legal fitness to drive influenced by BEMD

Better eye mean deviation (BEMD) strongly affects a patient's legal fitness to drive (LFTD), according to recently published data.

The retrospective investigation, led by Professor David P Crabb, Department of Optometry and Visual Science, City University London, London, UK, assessed the monocular 24-2 visual fields (VFs) of 2604 patients with bilateral VF damage.

LFTD was assessed using integrated VFs. The BEMD and worse eye MD (WEMD) were used to compare and evaluate respective diagnostic capabilities to predict LFTD.

The results revealed BEMD as a good predictor of the VF component for LFTD. There was no significant additional diagnostic power from MDs from both eyes. Probability of Failure (PoF) for various defect levels of ≤−10 dB and ≤−14 dB were 70 for 95% CI 66% to 74% and 92% for 87% to 95%, respectively.

Readily available MD values can provide pratical landmarks for VF disability for glaucomatous patients.

The abstract can be found in the current issue of the British Journal of Ophthalmology .