Diabetic retinopathy in type 1 diabetes mellitus. A study on medical risk indicators and treatment outcome.

Diabetic retinopathy is a common complication to diabetes mellitus and is still a major cause of impaired vision in the Western world. The aim of the present study was to identify medical risk factors influencing the development and progression of retinopathy in type 1 diabetic patients, and to investigate the effects of laser treatment on visual acuity and glare.

Although the development of sight-threatening retinopathy during a 10-year follow-up period was 37%, less than 1% of the patients became blind (VA£0.1). The development of retinopathy was associated with hyperglycemia and to some extent, a high blood pressure. In patients followed from the onset of the disease, no patient developed sight-threatening retinopathy during the first 10 years. Pregnancy per se did not seem to be a risk factor for progression of retinopathy but preeclampsia during pregnancy was. Although nephropathy and severe retinopathy are closely associated, we identified a subgroup of patients with proliferative retinopathy who did not develop any signs of nephropathy during 10 years of follow-up. Homocysteine did not seem to be an independent risk factor for retinopathy. Patients treated with photocoagulation for clinically significant macular edema had few complications and a good visual outcome. Despite a good visual outcome, many patients with panretinal photocoagulation for proliferative retinopathy express problems with glare. We could confirm their symptoms by demonstrating a prolonged visual recovery time during glare exposure. Thus, patients with type 1 diabetes mellitus who develop sight-threatening retinopathy can expect a good visual outcome due to early detection and photocoagulation treatment. Hyperglycemia and to some extent high blood pressure are risk factors for its development.