Transient proliferative diabetic retinopathy during intensified insulin treatment

Two women aged 22 and 19 years who had had diabetes for 11 and four years, respectively, developed proliferative retinopathy after five to seven months of significantly improved metabolic control. They were participants in two separate prospective studies including 97 insulin-dependent patients. At inclusion, one patient showed minimal background retinopathy and the other showed no retinopathy. Their level of glycosylated hemoglobin was initially high (14.3% and 17.5%) but within five to six months had fallen by 5.7% and 7.5%. The improved metabolic control was obtained by home blood glucose monitoring and insulin pump in the older patient and by home blood glucose monitoring only in the other. By maintaining near normoglycemia, regression of the proliferative retinopathy was achieved. Photocoagulation was not performed. After five and two years of follow-up, respectively, only mild background retinopathy has been noted in both patients. We concluded that a significant lowering of blood glucose may provoke proliferative retinopathy and that sustained good metabolic control may reverse this retinopathy without photocoagulation.