CHROMATIC STATIC PERIMETRY IN DIABETIC CHILDREN

Abstract

In order to evaluate the visual function we studied a group of 50 (26 female and 24 male) diabetic children without retinopathy. Their age ranged from 11 to 15 years with duration of the disease > 3 years, absence of fluoroangiographic signs of retinopathy, no diachromatopsia, stable glycosylated haemoglobin (HbAlc) from 6.3% to 12.1%. The patients were divided into 2 groups according to their HbAlc values of the last 12 montha:Group A1, HbAlc 3.8-9% (32 patients), Group A2, HbAlc 9.1-12.1% (18 patients). Other 2 subgroups were created according to Albumin Excretion rate (AER) values: Group B1, AER 0.1-15 mcg/min (36 patients), Group B2, AER 15.1-87.2 mcg/min (14 patients). Computerized static perimetry (CSP) evaluating retinal threshold in central visual field (24°) was performed with white and blue stimuli (Allergan Humphrey model 640 HFA). Three concentric areas of the visual field were identified: SI:0-9°, S2:10-18°, S3:>18°. The Group A2 in comparison with Group A1 showed a significant reduction of the Bensitivity to blue stimuli (S1:p=0.039, S2:p=0.043, S3: p=0.006), while no significant difference was found for the white stimuli. In Group B2 in comparison with Group B1 a significant reduction of the sensitivity to white stimuli in S3 area (p=0.043) and to blue stimuli in all areas (Si: p=0.003, S2: p=0.008, S3: p=0.005) was found. This study shows that diabetics without fluoroangiographic signs of retinopathy can have a significant impairment of the visual field. The CSP performed with blue stimuli seems to be an appropriate and suitable method to evaluate the earliest retinal functional damages.