Visual impairment in type 2 diabetic patients. A multicentre study in France. CODIAB-INSERM-ZENECA Pharma Study Group

The prevalence and causes of visual impairment have been estimated in a sample of 423 Type 2 diabetic outpatients, aged 35 to 74 years, recruited in 8 centres from all parts of France. The presence of retinopathy was assessed by fluorescein angiography with centralized interpretation. The presence of cataract and glaucoma was also recorded. Prevalence of blindness was 1.2%. Moderate visual impairment affected 7% of the patients. The major cause of blindness was cataract, explaining 38% of the cases of blindness. Retinopathy was associated to blindness in 2 cases out of 26. More than half of the patients with proliferative retinopathy and the third of those who had macular edema had been treated by photocoagulation. According to the present patient material, retinopathy is a minor cause of visual impairment in Type 2 diabetic patients, cataract remaining the major cause. This reflects the introduction of photocoagulation into ophthalmologic practice.