EFFECT OF MULTIPLE DAILY INSULIN INJECTIONS ON COURSE OF DIABETIC-RETINOPATHY

Diabetic patients [42] on insulin once a day in the early stage of diabetic retinopathy were randomly assigned to 1 of 2 kinds of insulin regimen, i.e, single or multiple daily injections. Retinal changes were quantitatively estimated by counting the microaneurysms (MA) observed on fluorescein angiograms at the posterior pole of the more diseased eye. Baseline characteristics of the 2 groups were not significantly different. These included duration of diabetes, age at diagnosis, daily dose of insulin, amount of urinary sugar excreted in 24 h, fasting blood sugar (FBS) and number of MA. During the follow-up (mean duration of 3 yr) the mean yearly progression in the number of MA was significantly less in the multiple- than in the single-injection group: 1.8 .+-. 0.7 vs. 7.2 .+-. 1.9 (P < 0.01; nonparametric test: P < 0.02). Final vaules were, respectively, MAs: 15.2 .+-. 4.9; 33.0 .+-. 7.9; glycosuria (g/24 h): 20.6 .+-. 2.5; 27.5 .+-. 4.3; FBS (mg/100 ml): 154 .+-. 15; 195 .+-. 11. P values comparing the 2 groups were < 0.02, < 0.02 and < 0.05. In this clinical trial, made under routine treatment conditions, the use of divided daily insulin injections was effective in improving diabetic control and delaying retinal changes.