Abstract
A prospective long-term study on the predictive value of nyctometry in the development of proliferative diabetic retinopathy in insulin-dependent diabetes mellitus is in progress. Sixty-one patients participated. At a follow-up 3 years after the initial investigation, none of the patients initially showing results above the lower normal limit had developed proliferative retinopathy, whereas 6 out of 16 eyes initially displaying reduced values of nyctometry had advanced into proliferative retinopathy. It is concluded that nyctometry is valuable as an easily performed screening method in selecting those at risk of developing proliferative retinopathy within a few years.