Blood-retina barrier permeability and its relation to the progression of diabetic retinopathy in type 1 diabetics. An 8-year follow-up study.

Blood-retina barrier (BRB) permeability and its relation to the progression of diabetic retinopathy was studied over an 8-year period in 50 insulin-dependent diabetic patients. Initially, the patients underwent an ophthalmological examination, including measurement of best corrected visual acuity, fundus photography and vitreous fluorometry for determination of BRB permeability. After 8 years the patients were reexamined and their retinal status and clinical course were evaluated. We found a positive correlation between a high initial permeability value and an unfavorable clinical course using the parameter photocoagulation. A decrease in follow-up visual acuity was also associated with high initial permeability; however, this correlation was not statistically significant. A significant difference in mean blood pressure was found between values measured in laser-treated patients vs a group that did not undergo such therapy. Thus, in patients showing the same initial retinal morphology, high permeability seems to indicate an unfavorable disease course. The extent to which BRB permeability can be a valuable supplement to fluorescein angiography and three-mirror examination in the clinical decision process needs to be further evaluated.