Alberto Verrotti

Blue-on-yellow and achromatic perimetry in diabetic children without retinopathy.

OBJECTIVE: We compared blue-on-yellow perimetry with achromatic perimetry to determine whether the first was more sensitive in detecting visual field defects. RESEARCH DESIGN AND METHODS: We studied 50 children and adolescents (22 male, 28 female) with IDDM, ranging in age from 10.1 to 16.3 years (mean 13.3+/-2.1 years), with a disease duration of 5.2-10.0 years (mean 7.1+/-1.9 years). Patients were divided into subgroups according to the presence of persistent microalbuminuria. No one had signs of diabetic retinopathy when studied with fluorescein angiography. RESULTS: By achromatic perimetry, the analysis of subareas of the central 30 degrees of the visual field (0-9 degrees; 10-18 degrees; out of 18 degrees) showed no differences between diabetic subgroups in the central 18 degrees of the visual field, while a significant difference between the same subgroups was found outside the 18 degrees of the 24-2 program of the Humphrey perimeter (P = 0.027). By blue-on-yellow perimetry, in all three of the perimetric subareas evaluated, the sensitivity was lower in microalbuminuric patients than in normoalbuminuric ones. The differential sensitivity between the perimetric tests performed with blue-on-yellow and with achromatic stimuli showed statistically significant data, with a higher level of significance in the central 18 degrees (P < 0.0001) than outside the 18 degrees (P = 0.033). CONCLUSIONS: Our study suggests that blue-on-yellow perimetry is more useful and more sensitive than achromatic perimetry in the detection of preclinical visual field defects in diabetic children with microalbuminuria but without clinically detectable retinopathy.

Visual evoked potentials in young persons with newly diagnosed diabetes: a long‐term follow‐up

To evaluate the presence of electrophysiological abnormalities in the visual function of young persons with diabetes, visual evoked potentials were recorded, in basal conditions and after photostress, in 30 patients with newly diagnosed insulin‐dependent diabetes mellitus. Their mean age was 17.6 years (3.6 SD), and their glycosated haemoglobin (HbA1c) was 9.4% (1.6 SD). Thirty healthy age‐ and sex‐matched individuals were evaluated as the control group. This study showed that the P100 latency was significantly delayed in patients with diabetes compared with the control group (p<0.01), while the N75 to P100 amplitude was similar in both groups. These measurements were repeated after 6 months, when all participants with diabetes had achieved good metabolic control (HbA1c 7.2% [1.5 SD]). At this second evaluation a complete normalisation of all parameters was observed. These findings suggest that early functional abnormalities of the optic nerve can be detected at onset of diabetes, and that glycaemic control reverses these abnormalities.

BLUE-ON-YELLOW AND ACHROMATIC PERIMETRY IN DIABETIC CHILDREN WITHOUT RETINOPATHY

OBJECTIVE We compared blue-on-yellow perimetry with achromatic perimetry to determine whether the first was more sensitive in detecting visual field defects. RESEARCH DESIGN AND METHODS We studied 50 children and adolescents (22 male, 28 female) with IDDM, ranging in age from 10.1 to 16.3 years (mean 13.3+/-2.1 years), with a disease duration of 5.2-10.0 years (mean 7.1+/-1.9 years). Patients were divided into subgroups according to the presence of persistent microalbuminuria. No one had signs of diabetic retinopathy when studied with fluorescein angiography. RESULTS By achromatic perimetry, the analysis of subareas of the central 30 degrees of the visual field (0-9 degrees; 10-18 degrees; out of 18 degrees) showed no differences between diabetic subgroups in the central 18 degrees of the visual field, while a significant difference between the same subgroups was found outside the 18 degrees of the 24-2 program of the Humphrey perimeter (P = 0.027). By blue-on-yellow perimetry, in all three of the perimetric subareas evaluated, the sensitivity was lower in microalbuminuric patients than in normoalbuminuric ones. The differential sensitivity between the perimetric tests performed with blue-on-yellow and with achromatic stimuli showed statistically significant data, with a higher level of significance in the central 18 degrees (P < 0.0001) than outside the 18 degrees (P = 0.033). CONCLUSIONS Our study suggests that blue-on-yellow perimetry is more useful and more sensitive than achromatic perimetry in the detection of preclinical visual field defects in diabetic children with microalbuminuria but without clinically detectable retinopathy.