DIABETIC-RETINOPATHY AT THE TIME OF DIAGNOSIS OF NIDDM IN SOUTH INDIAN SUBJECTS

Several studies from the U.K. and the U.S. have shown that retinopathy was present at diagnosis of non-insulin dependent diabetes mellitus ( NIDDM) indicating the likelihood of a latent phase of hyperglycaemia f or a long period. This study looked for the prevalence of retinopathy at diagnosis of NIDDM in South Indian subjects who have a fairly high prevalence of diabetes and also a high rate of undetected diabetes. On e thousand NIDDM subjects with varying duration of diabetes underwent detailed opthalmoscopic examination for retinopathy. It was noted that the prevalence of retinopathy increased linearly with duration of dia betes. Among the 60 newly diagnosed NIDDM, 4 (6.7%) subjects had backg round diabetic retinopathy. Using a weighted linear regression analysi s with percentage of retinopathy in relation to duration, it was estim ated that hyperglycaemia could have been present 4.1 years prior to th e diagnosis of NIDDM. Although the prevalence of retinopathy at diagno sis in South Indian NIDDM was lower than the other reported values, in view of the high prevalence of diabetes in Indians, a large number of patients would have the risk of microangiopathy even before diagnosis of diabetes is made.