Aqueous flare and retinal capillary changes in eyes with diabetic retinopathy

We examined 112 eyes of 112 adult-onset diabetic patients by fundus fluorescein angiography and with the laser flare cell meter (LFCM) in order to evaluate the possible correlation between retinal capillary changes and aqueous flare. Diabetic eyes were divided into the following groups: minor background diabetic retinopathy (MDR), nonproliferative diabetic retinopathy with predominant capillary occlusion (ONP), nonproliferative diabetic retinopathy with predominant capillary dilation and exudation (ENP) and proliferative diabetic retinopathy (PDR). 108 age-matched eyes of 108 normal subjects were used as control group. Flare values (photon counts/ms) of all diabetic groups (MDR 9.01 +/- 0.79, ONP 13.66 +/- 3.22, ENP 16.43 +/- 5.55, PDR 18.57 +/- 6.99) were significantly higher than in the normal control group (4.28 +/- 1.14, p < 0.0001). Significant differences were found between ONP and ENP (p = 0.008) and between ONP and PDR (p = 0.0001) but not between ENP and PDR (p = 0.4). Our results indicate that there is a correlation between aqueous flare and the type of angiographic retinal capillary changes with higher flare values in eyes with retinal capillary dilatation and exudation. Measurements with LFCM may be useful to quantify the extent and severity of capillary alterations in diabetic eyes.