Assessing Spatial and Temporal Properties of Perimetric Stimuli for Resistance to Clinical Variations in Retinal Illumination

作者:Swanson William H*; Dul Mitchell W; Horner Douglas G; Liu Tiffany; Tran Irene
来源:Investigative Ophthalmology & Visual Science, 2014, 55(1): 353-359.
DOI:10.1167/iovs.13-11640

摘要

PURPOSE. To develop perimetric stimuli for which sensitivities are more resistant to reduced retinal illumination than current clinical perimeters. METHODS. Fifty-four people free of eye disease were dilated and tested monocularly. For each test, retinal illumination was attenuated with neutral density (ND) filters, and a standard adaptation model was fit to derive mean and SEM for the adaptation parameter (NDhalf). For different stimuli, t-tests on NDhalf were used to assess significance of differences in consistency with Weber's law. Three experiments used custom Gaussian-windowed contrast sensitivity perimetry (CSP). Experiment 1 used CSP-1, with a Gaussian temporal pulse, a spatial frequency of 0.375 cyc/deg (cpd), and SD of 1.5 degrees. Experiment 1 also used the Humphrey Matrix perimeter, with the N-30 test using 0.25 cpd and 25 Hz flicker. Experiment 2 used a rectangular temporal pulse, SDs of 0.25 degrees and 0.5 degrees, and spatial frequencies of 0.0 and 1.0 cpd. Experiment 3 used CSP-2, with 5-Hz flicker, SDs from 0.5 degrees to 1.8 degrees, and spatial frequencies from 0.14 to 0.50 cpd. RESULTS. In Experiment 1, CSP-1 was more consistent with Weber's law (NDhalf 6 SEM = 1.86 +/- 0.08 log unit) than N-30 (NDhalf = 1.03 +/- 0.03 log unit; t > 9, P < 0.0001). All stimuli used in Experiments 2 and 3 had comparable consistency with Weber's law (NDhalf = 1.49-1.69 log unit; t < 2). CONCLUSIONS. Perimetric sensitivities were consistent with Weber's law when higher temporal frequencies were avoided.

  • 出版日期2014-1