Frequency Doubling Technology threshold testing in the pediatric age group

Purpose: To evaluate the feasibility of performing visual field with the Frequency Doubling Technology (FDT) in children aged 5 to 10 years. Patients and Methods: Forty healthy children and fifteen healthy adults, all with no previous experience with visual field testing, underwent visual field testing with the C20 threshold test of the Carl Zeiss Meditec FDT analyzer in both eyes. The subjects were divided into three groups. Group A (age 5-7), group B (age 8-10), and group C (adults). Results: The mean explanation time for the test was 83 ± 43 seconds for group A, 68 ± 31 seconds for group B, and 37 ± 15 seconds for group C (P < 0.001 for the difference between group C and groups A and B). Test performance time for the right eye was 347 ± 57 seconds, 301 ± 21 seconds, and 298 ± 35 seconds for groups A to C, respectively (P < 0.001 for the difference between group A and groups B and C). Forty percent of the children, but none of the adults required two demonstrations prior to initiation of the test. In children fixation losses for the right and left eye were 10% and 37% respectively. No fixation losses occurred in adults. In both eyes a mean deviation <0.5% occurred significantly more often in group A than in group C (P = 0.013). Conclusion: Visual field testing with FDT in the young age group is feasible. Test reliability was similar between children aged 5 to 7 and 8 to 10. Pre-selection of children is suggested to achieve reliable results.