Effect of vitamin E on platelet aggregation in diabetic retinopathy.

The effect of vitamin E on platelet aggregation was investigated in a group of 10 patients with diabetic retinopathy. Adenosine diphosphate induced platelet aggregation was inhibited in the patients' group as well as in the controls in the presence of vitamin E. An increased platelet aggregation was obtained with arachidonic acid in both groups when platelet-rich plasma was incubated prior with vitamin E. The clot retraction inhibition test parallels the findings of aggregation obtained with the platelet aggregation meter.