Morphology and Repeatability of Automated Perimetry using Stimulus Size VI: A Comparison with Sizes III and V

摘要

? Purpose: ?To describe the visual field of normal subjects using Humphrey perimetry with size VI stimuli and to compare size VI thresholds and retest variability with perimetry using sizes III and V stimuli. ? Methods: ?We tested one eye of 60 normal subjects with the Humphrey full threshold algorithm using sizes V (1.72°) and VI (3.44°) stimuli and with SITA-Standard? using size III stimuli (0.43°). The patients were retested 1-4 weeks later. We compared the mean scores, concentric zones, and point-wise sensitivities among the sizes and their retest variability. Repeated measures ANOVA on Ranks was performed with the dependent variable as sensitivity (dB) of average sensitivity of each eccentric zone. ? Results: ?The mean sensitivities were size III: 30.2 ± 1.1; V: 34.4 ± 1.0 and VI 36.0 ± 1.0 (p 0.001 with all Tukey post hoc paired comparisons significant). Significant differences between the groups were also present for each eccentric zone except 0° for size V vs. size VI. The mean difference on retest across test locations was 1.55 dB ± 1.37 for size III, 1.36 dB ± 1.23 for size V, and 1.27 dB ± 1.15 for size VI. The difference in variability between size III, V and size VI increased with eccentricity, with size III increasing more than the larger stimulus sizes but statistical significance for this difference was not reached. (Figure). ? Conclusions: ?The retest variability in normal subjects is slightly less for sizes V and VI full threshold testing compared with size III SITA-Standard? results and for larger sizes there is a minimal increase with eccentricity. ?View OriginalDownload SlideView OriginalDownload Slide ? Keywords: perimetry ? visual fields?.