To be eligible for a driving licence in the UK, all drivers must be able to read a standard number plate at a distance of 20 metres; however, anyone receiving insulin treatment and/or who has diabetic retinopathy (DR) is required to inform the Driver and Vehicle Licensing Agency (DVLA). Those with bilateral-treated diabetic retinopathy are usually required to undergo a visual field test. Drivers who fail the current visual test have their licences refused or revoked. The DVLA defines a minimum requirement for peripheral and central fields of vision, and also visual field defects that are considered acceptable and unacceptable. Exceptionally, the DVLA may allow current licence holders who do not meet the visual field criteria but who have a stable condition to retain their licence. Further information on the current medical standards of fitness to drive, including visual standards, are published in the At a Glance Guide to the Current Medical Standards of Fitness to Drive (DVLA, 2005) (Chapter 3 on ‘Diabetes Mellitus’ and Chapter 6 on ‘Visual Disorders’ are reproduced in Appendices 1 and 2). The At a Glance Guide is freely available to all general practitioners, consultants and the public on the DVLA website (http://www.dvla.gov.uk). Currently, DR is regarded as a progressive condition, even after laser treatment; therefore, no individual with DR can be considered as an exceptional case in respect of the visual standard. However, a growing body of opinion, supported by considerable clinical experience and some research, suggests that DR, once adequately treated, can remain stable for many years. Moreover, some patients may be able to compensate for certain visual field defects. Therefore, there is an urgent need to reassess the current visual standards and assessment methods for people with DR. The workshop was convened to address the following aims: • To evaluate the effect of DR and its treatment on visual function and the implications of both the condition and its treatment for driving safety. • To consider DR and visual function beyond the current standards, which are based on visual acuity and visual fields, and to consider other elements of visual function, such as contrast sensitivity and glare, where such information exists. • To understand the risk and rate of progression of DR at the various stages of the disease, the likelihood of progression affecting visual function, and the possibility of anticipating or evaluating such progression in individual cases. • To discuss whether DR and visual function can be considered as permanently stable and, if possible, to define stable defects. • To review the literature on visual function in DR and to consider individual case reports where appropriate literature is lacking. These topics were explored in both formal presentations and open discussions. Also considered were several key issues raised at an earlier meeting of lay-interest groups representing individuals with diabetes and DR. These issues are summarised in Section 4 below (‘Key concerns from the lay meeting’). The workshop considered only Group 1 drivers; Group 2 drivers are subject to more exacting safety requirements. Nor was the workshop intended to pronounce on standards of vision that might be suitable for driving, as these standards are the subject of a wider debate within the European Union and the World Congress of Ophthalmology. However, the DVLAwishes to ensure that its own visual standards for driving are consistent with those under discussion elsewhere. The workshop participants were drawn from leading ophthalmologists and diabetologists in the UK, expert and lay members of the DVLA Medical Advisory Panel on Driving and Visual Disorders, and medical officers from the DVLA and Department for Transport (DfT). The event was managed by an independent organisation, The At Work Partnership, which was also responsible for writing and editing the workshop proceedings. (Author/publisher)
Samenvatting