Passing the DVLA field regulations following bilateral macular photocoagulation in diabetics

At present the Driver and Vehicle and Licensing Agency (DVLA) of the UK requires all diabetic patients with laser treatment in both eyes to undergo a binocular driving field assessment. Increasingly we find that many such patients have undergone only macular laser treatment without panretinal photocoagulation. We aimed to ascertain the frequency and causes of failure of the binocular driving field test after bilateral macular laser treatment performed according to a set protocol.

A retrospective case notes study was combined with a prospective recall of patients for visual field assessment. All diabetic patients under the care of one consultant who had had bilateral macular laser treatment (without panretinal photocoagulation) over a 4 year period were identified and the case notes studied. Patients who could not achieve a corrected binocular acuity of 6/9 were excluded, as were patients with glaucoma. Patients who had not had the DVLA test were recalled to perform the test, whether or not they had an intention to drive. Failure was defined utilising strict criteria on the Esterman Programme of the Humphrey Analyser.

A total of 138 patients were identified. Fifty-four were not eligible (21 because of poor acuity, 29 had died or were too ill to participate and 4 for other reasons). Of the 84 who were eligible, 64 had visual fields performed and 20 declined to attend. Sixty-three of 64 tested passed the Esterman test, the one failure having a previously unknown and relatively mild homonymous field defect.

Patients undergoing bilateral macular laser can be counselled that, provided their acuity remains adequate, they have a very low chance of failing the DVLA field regulations.