[Diabetic retinopathy and associated risk factors in type-1 and type-2 diabetics in the Upper Palatinate]

Diabetic retinopathy is the main cause of blindness in industrial countries. This study was undertaken to determine the prevalence of diabetic retinopathy and risk indicators among volunteers in a rural district in Bavaria, Germany.

Using a mobile survey unit, we investigated 627 diabetic volunteers (275 women, 352 men, mean age 64.5 +/- 12.5 yr) in 23 cities and villages. One retinal Polaroid photo was taken per eye, using a non-mydriatic camera (Canon CR4-45 NM).

In 60 subjects (9.6%) retinal photographs were not assessable. Among the remaining 567 patients (76 type-1 diabetes, HbA1c 7.3 +/- 1.2% and 491 type-2 diabetes, HbA1c 7.7 +/- 1.5%) in 72.3% no retinopathy was found (57.9% type-1 diabetes/74.5% type-2 diabetes). Non-proliferative retinopathy was diagnosed in 22% (38.2%/19.6) and proliferative retinopathy in 5.6% (3.9%/5.9%). Photocoagulation scars were present in 6.1% (11.7%/5.3%) and macular oedema in 11.8% (14.1%/11.6%). In 6.1% (5.3%/6.6%) of patients visual acuity was less than 0.1 in at least one eye. The degree of retinopathy was found to be related to the duration of diabetes mellitus, age at onset, glycaemic control (HbA1c), blood pressure and symptoms of neuropathy.

The prevalence of retinopathy of 22.0% in the study group was found to be low for non-proliferative diabetic retinopathy, perhaps due to the methods used and/or good or acceptable glycaemic control measured as HbA1c.