ACTIVITY AREAS :: 8. Retinal Diseases
1. Progress
1.1 Age-related macular disease (AMD) accounts for over 50% of blind registration in the UK, and treatment is of benefit to less than 5% of those affected. We have three clinics each week devoted largely to the investigation and care of patients with this disorder, and we see about 20 new cases each week. New forms of treatment are being sought. We took part in an International multicentre trail of alpha-interferon treatment that proved negative. We are currently involved in a multicentre trial of ionising radiation, and single centre trial of photocoagulation as prophylaxis for patients at high risk of loosing vision in their second eye. A randomised controlled trial of prophylaxis is also underway.
1.2 We have identified evidence that polypoidal choroidopathy, which was thought to be confined black patients, is common in the Caucasian population. A cross-sectional study is currently underway to determine its prevalence in our population with AMD. The importance of this work is underlined by the observation that treatment of this variant appears to be effective.
1.3 A study of our patients has shown that there is undoubtedly a genetic component to AMD, and evidence from others implies that it is a complex disorder. Blood is being collected from our patients, and their siblings for molecular genetic studies. They are being segregated according to their phenotype using photography, fluorescein angiography and autofluorescence imaging. Spouses of patients free of AMD provide a comparison group.
1.4 In parallel, histological studies are being undertaken to document the variation of age-changes at the macula. The findings are compatible with the concept that several genes are involved in conferring risk of visual loss.
1.5 Another major age-related eye disease whose symptoms are often ignored is diabetic retinopathy. This potentially blinding disorder is a complication of diabetes that causes abnormal changes in the blood vessels throughout the body, including the retina. We have completed a co-ordinated programme for diabetic retinopathy screening in conjunction with local optometrists and outreach sites. The value of screening for this condition is now being assessed. Ocular neovascularisation is the cause of the majority of visual loss in diabetes. Following a successful demonstration of altered growth factor levels in the pathogenesis of diabetic eye disorders, treatment trials have been developed aimed at therapeutic manipulation of the growth factors. This very important area of research is supported by an award from the British Diabetic Association.
