Decreased formation of aqueous humour in insulin-dependent diabetic patients.

The rate of aqueous humour formation was measured by fluorophotometry in 34 insulin-dependent diabetic patients and 12 non-diabetic controls to determine whether or not aqueous flow in diabetics differed from that of normal controls, and whether or not aqueous flow among diabetics was correlated with the stage of retinopathy. Diabetic patients were divided into three groups based on the degree of retinopathy; group I without retinopathy, group II with minimal to moderate non-proliferative retinopathy, and group III with proliferative retinopathy. Aqueous flow (mean, SD) in diabetic patients was: 1.55 (0.32) microliter/min in group I, 1.51 (0.47) microliter/min in group II, and 1.26 (0.39) microliter/min in group III. No statistically significant difference was found among these three diabetic groups. Aqueous flow in the non-diabetic controls was 2.18 (0.40) microliter/min, and this was statistically significantly greater than in each of the diabetic groups. Intraocular pressure, age, duration of diabetes, haemoglobin A1C, and blood glucose levels had no significant effect on aqueous flow in diabetic patients.