The blood-retina barrier and blood-aqueous humor barrier in type I diabetic patients without retinopathy. Determination of permeability using fluorophotometry and laser flare measurements

Abstract

Possibly early functional disruption of the blood-ocular barrier in eyes of insulin dependent type I diabetics without manifestation of retinopathy can be detected using fluorophotometry and laser flare measurement. In order to evaluate blood-retinal (BRB) and blood-aqueous-barrier (BAB) permeability fluorophotometry was performed in 34 eyes of 34 insulin-dependent type-I diabetics without retinopathy, additionally the aqueous laser flare was measured. 34 normal eyes of 34 age-matched subjects served as controls. BRB permeability (3.2 +/- 1.3 x 10(-7) cm/s) was increased with low significance (p = 0.019) in diabetic eyes (controls: 2.6 +/- 0.7). The permeability coefficient of BAB was found to be increased in diabetics (5.3 +/- 1.8 x 10(-4)/cm) with higher significance (controls: 3.7 +/- 0.7; p = 0.00003); laser flare values in diabetic eyes (5.0 +/- 1.2 photon counts/ms) were significantly higher than in controls (4.1 +/- 1.0; p = 0.003). In diabetics there was a significant correlation (r = 0.3; p = 0.014) between the laser flare values and the permeability coefficient of BAB. In type-I diabetics without retinopathy BRB permeability seems to be increased slightly as well as laser flare in the aqueous; the BAB permeability coefficient seems to be the most sensitive parameter in a beginning affection of the blood-ocular barrier.