Studies of retinopathy and the plasma co-factor of platelet hyperaggregation in type 1 (insulin-dependent) diabetic children.

Only one out of 73 children with young-onset Type 1 (insulin-dependent) diabetes for less than 10 years had retinopathy detectable with fluorescein retinal angiography. Although these fluorescent studies were normal, retinal abnormalities were detected in 19 out of 53 patients by electro-retinography and in four out of 28 patients by the 100-hue colour test. We were unable to confirm recent reports indicating that most Type 1 diabetic patients have retinopathy detectable by fluorescein angiography. The diabetic plasma co-factor induces normal platelets to hyperaggregate in vitro. Plasma co-factor activities in adult diabetic patients have previously been shown to correlate with the degree of hyperaggregation, although in general, only those patients with severe retinopathy or nephropathy have high plasma activities. The plasma activities of 192 Type 1 diabetic patients were significantly higher than those of normal subjects (p less than 0.01). Of ten children with markedly elevated activities, nine did not have retinopathy.