Vitreous fluorophotometry in juvenile diabetes

A group of 26 juvenile diabetics, 8-22 years old with a mean duration of diabetes of 7.8 +/- 5.7 years were examined by vitreous fluorophotometry. Eleven non-diabetic healthy individuals, 12-27 years old, served as controls. Vitreous fluorescein concentrations one hour after injection of fluorescein were higher in the diabetics than in the controls indicating an abnormal blood-retinal barrier. In diabetes beyond the partial remission period a pronounced leakage of fluorescein into the vitreous body occurred, while diabetics still in partial remission showed no such abnormal leakage. There were no significant correlations between a defect blood-retinal barrier and duration or age at onset of diabetes. Some diabetic patients showed an abnormal leakage with a duration of diabetes less than 2 years, while some other patients with a duration of more than 16 years did not have an abnormal blood-retinal barrier. The diabetics with defect blood-retinal barrier had a lower glucosuria index during the last year, indicating a more inadequate metabolic control than those patients who had a normal barrier. There was no relation between the actual blood-glucose value during the examination and abnormal leakage. In some diabetics, all beyond partial remission significantly elevated fluorescein concentrations were also found in the anterior parts of the vitreous body, indicating a break-down of the blood-aqueous barrier as well. In conclusion, vitreous fluorophotometry provides information about early, functional and possibly reversible retinal changes in juvenile diabetes. The observation that the blood-retinal barrier remained intact during the remission period supports the hypothesis that normoglycemic metabolic control is of importance for the preservation of a normal blood-retinal barrier function.