The reliability of frequency-doubling technology (FDT) perimetry in a pediatric population.

PURPOSE: Frequency-doubling Technology IFDT) Perimetry was introduced as a rapid, easy method for detection of visual-field defects in adults. Its reliability, howev, has never been tested among pediatric patients. The purpose of this study was to determine if children could complete a screening program of FDT Perimetry reliably and to define the age range over which it might be most applicable.
METHODS: Two hundred fifty-nine normal children (mean age, 10.7 years; range, 4 to 17 years) were asked to complete the FDT C-20-1 screening test as part of their general eye examination. The visual-field results were analyzed for reliability using the number of false-positive errors, fixation losses, and visual-field defects. For the purposes of this analysis, field results were considered unreliable with false-positives > or = 1 or fixation errors > or = 1. The visual-field test was also considered unreliable if > 2 sectors were flagged.
RESULTS: Data from 254 children were included in the analysis. Five children were excluded because of suspected malingering or ocular health diagnosis that may have produced a visual-field defect. False-positives were less than one for all but the youngest age group 14 years old). Fixation errors decreed with increasing age and fell below one (became reliable) at approximately 9 years of age, and remained less than one through 17 year. Visual-field loss for purposes of this study when present in more than two sectors was considered unreliable in this normal population.
CONCLUSIONS: Children ages 10 years of age and older can reliably complete the FDT C-20-1 screening field test using the strictest criteria, combining false-positives, fixation losses, and visual-field losses. These data are derived from normal subjects, who on complete eye examination, had no ocular disease or reason to suspect visual-field defects.