Ocular fluorophotometry in insulin-treated diabetic patients with and without retinopathy

To look for possible determinators of the pathological readings of vitreous fluorophotometry in diabetes reported by other groups, we studied 32 insulin-treated patients, 22 of whom had fluorescein angiograms without pathological changes, while 10 had background retinopathy. 14 healthy subjects matched for age and blood pressure served as controls. Sodium fluorescein, 17 mg/kg body weight, was injected intravenously and ocular fluorophotometry performed 60 and 120 minutes later. Blood drawn 5, 45 and 120 minutes after the injection was assayed for total and ultrafiltrable fluorescein and the intraocular readings corrected for average preceding free plasma fluorescein. Patients without retinopathy did not differ from controls in any intraocular measure, while patients with retinopathy showed significantly increased readings in the posterior (60 min: 12 +/- 7 vs. 6 +/- 4, p less than 0.01, 120 min: 26 +/- 35 vs. 11 +/- 5, p less than 0.05) and middle vitreous (60 min: 6 +/- 3 vs. 3 +/- 3, p less than 0.001, 120 min: 11 +/- 5 vs. 8 +/- 5, p less than 0.01 (X 10(-9) g/ml fluorescein, mean +/- SD)). No significant relations to systolic or diastolic blood pressure, blood glucose, hemoglobin Alc or serum creatinine were found in any of the diabetic groups. Re-examination of 7 patients 4-14 days later in a non-fasting state showed no significant changes.