Objective: To determine the flicker fusion frequency in children and adolescents with insulin-dependent diabetes mellitus (IDDM) who did not have fluorescein angiographic signs of retinopathy.
Design: Cross-sectional study.
Setting: Antidiabetic Centre, departments of Ophthalmology and Pediatrics, University of Chieti, Chieti, Italy.
Patients: Forty-five patients aged 9 to 18 years with IDDM without fluorescein angiographic signs of retinopathy. Forty-five healthy subjects matched for sex and age constituted the control group. The patients were classified into two subgroups according to their metabolic control: good (percentage hemoglobin Alc 9% or less) or poor (percentage hemoglobin Alc greater than 9%).
Outcome measures: Retinal flicker fusion frequency, evaluated with an automated flicker perimeter in the central 30 degrees of the visual field.
Results: The subjects with poor metabolic control had a significantly lower mean flicker fusion frequency than the control subjects (27.43 Hz [standard deviation (SD) 5.16 Hz] vs. 38.72 Hz [SD 4.27 Hz]) and the patients with good metabolic control (33.94 Hz [SD 5.54 Hz]) (p < 0.001). There was a significant relation between flicker fusion frequency and the percentage of hemoglobin Alc (r = -0.533, p < 0.001).
Conclusions: Our results show that children with poorly controlled IDDM without fluorescein angiographic signs of retinopathy have an impairment of retinal flicker sensitivity in the central 30 degrees of the central visual field and that this impairment is related to the degree of metabolic control. Flicker perimetry is a simple, noninvasive tool that may be useful to evaluate the eye function of diabetic children.