EARLY NEPHROPATHY PREDICTS VISION-THREATENING RETINAL DISEASE IN PATIENTS WITH TYPE-I DIABETES-MELLITUS

In type I (insulin-dependent) diabetes mellitus, nephropathy may be id entified in its early stages by the development of persistent microalb uminuria. This longitudinal study sought to examine the development of vision-threatening retinal disease (VTRD) (proliferative retinopathy and clinically significant macular edema) in such patients with early and evolving diabetic kidney disease. Eighty patients with type I diab etes and at least 8 yr of longitudinal data were identified. Glycated hemoglobin and albumin excretion rate (AER) were measured every 3 mo. Ophthalmologic examination was performed at least yearly. Thirteen pat ients were identified as having evolving nephropathy by a progressive increase in AER and the presence of microalbuminuria during the study period. Sixty-seven patients remained persistently normoalbuminuric. V TRD developed in eight of 13 (62%) patients with evolving nephropathy compared with five of 69 (7%) patients who were persistently normoalbu minuric (P < 0.001) in the absence of any difference in long-term glyc emic control or duration of diabetes between the two groups. Clinicall y significant macular edema (P < 0.05) and proliferative retinopathy ( P < 0.01) were both more common in patients with evolving nephropathy. In such patients, AER was 150 x/divided by 1.7 mu g/min at the time o f laser photocoagulation for VTRD. These data suggest that patients wi th type I diabetes and evolving nephropathy may be at higher risk of d eveloping VTRD than patients who remain persistently normoalbuminuric despite similar long-term glycemic control and duration of diabetes.