A Prospective Clinical Study of the Effects of Panretinal Photocoagulation Delivered With a Multi-spot Photocoagulator on Retinal Sensitivity and Driving Eligibility in Patients With Diabetic Retinopathy

Despite improvements in the management of diabetes, the incidence of severe diabetes -related eye disease remains high. Laser treatment (panretinal photocoagulation (PRP)) is the gold standard treatment for reducing the risk of visual loss. However, evidence suggests that PRP can be damaging on visual field function and thus jeopardize patients' eligibility to drive. In the UK, it is the patient's responsibility to inform the DVLA that they are receiving retinal laser.

With the use of a multi-spot Photocoagulator for application of PRP at Moorfields the investigators are in a unique position to assess the effects of laser applied with this new delivery system on visual fields in a detailed fashion. Thus providing more accurate advice on visual prognosis and visual field function and addressing the risk of losing the ability to drive.

All treatment-naive patients with severe diabetic retinopathy requiring bilateral retinal laser treatment will be identified. Following informed consent these patients will undergo baseline visual field testing which will be of a duration of approximately 30 minutes and complete a quality of life questionnaire. All patients will receive their laser treatment as part of standard clinical care via the multi-spot Photocoagulator which will require approximately four 20 minute sessions. At 6 months following the completion of treatment the patients will undergo repeat visual field testing as conducted at baseline and complete a quality of life questionnaire. The investigators hope to recruit 100 patients.

Analysis of visual fields will principally involve assessment of whether patients have met the UK driving standards on Estermann VF testing. A quantitative assessment of change in retinal sensitivity will be undertaken by comparing retinal sensitivity pre and post-PRP.