GLUCOSE-CONCENTRATION IN THE VITREOUS OF NONDIABETIC AND DIABETIC HUMAN EYES

Glycation (nonenzymatic glucosylation) of collagen may play a role in the primary pathology of the vitreous in diabetes. The extent of glyca tion is determined by the glucose concentration in the tissue. In this study glucose concentration was assayed in blood and vitreous samples obtained from three patient groups undergoing vitrectomy: nondiabetic patients (ND), diabetic patients with insulin-dependent diabetes mell itus (IDDM) and diabetic patients with non-insulin-dependent diabetes mellitus (NIDDM). In the ND group the glucose concentration in the vit reous (3.5+/-1.8 mM/l) was always lower than in the blood (9.1+/-3.5 m M/l). In the diabetic groups the vitreous glucose concentration was, w ith a few exceptions, generally lower than the blood glucose concentra tion. The vitreous glucose concentration in these groups was generally higher (IDDM 9.4+/-3.3 mM/l, NIDDM 7.2+/-3.9 mM/l) than in the ND gro up, and in 15 specimens exceeded 11 mM/l, a level increasing the proba bility of collagen glycation in the vitreous of diabetic patients.