These variations in HbA1c are also associated with other diabetic complications as evident in a multicenter study, which has established variation in HbA1C to be an important risk factor of diabetic retinopathy [27]. Tight blood glucose control significantly reduced the risk of microvascular complications in the Diabetes Control and Complications Trial (DCCT), which showed that intensive insulin therapy reduced incidence of albuminuria by 54% and decreased mean risk of retinopathy by 76% [14]. This evidence concerns the gene INS and retinal disorder.