Prevalence of diabetic retinopathy in relation to duration of diabetes mellitus in community hospitals of Lampang.

Three thousand and forty nine patients diagnosed with diabetes mellitus were examined in 13 community (district) hospitals in Lampang from January to December 2002. Complete eye examination with standard protocol was used to determine the prevalence and severity of diabetic retinopathy. The prevalence of the background or non-proliferative diabetic retinopathy (BDR or NPDR) was 18.9% and proliferative diabetic retinopathy (PDR) was 3% in all age groups. For the relationship of the duration of diabetes, it showed that the longer the duration of diabetes the higher the prevalence of diabetic retinopathy. In BDR or NPDR, the retinopathy varied from 13.11 to 22.91% in persons having diabetes for less than 10 years and up to 42.86% in those with diabetes for up to 20 years. In the PDR group, the prevalence was 2.15 to 2.42% in persons with diabetes for less than 10 years and up to 10.20% for those with diabetes for up to 20 years. The severity of retinopathy was found to be not only related to a longer duration of diabetes but also related to higher glycosylated hemoglobin levels, higher systolic blood pressure and the presence of proteinuria.