Correlation of Relative Dispersion Analysis and Other High Pass Resolution Perimetry Indices with Standard Threshold Perimetry

Purpose: Relative dispersion analysis (RDA), a new high pass resolution perimetry (HRP) index, appears to capture a novel aspect of visual field abnormality. The aim of this study was to evaluate the correlation of RDA and other HRP indices with the Humphrey perimeter parameters. Methods: Fifty-six eyes were randomly recruited from among patients at the authors’ clinic. Twenty-nine eyes were classified as glaucomatous (high intraocular pressure, abnormal visual field and/or optic disc) and 27 as ocular hypertensives (high intraocular pressure, normal visual field, normal optic disc defect). All the subjects were examined with the Humphrey perimeter, program 30-2, and HRP. The HRP data were also analyzed with the RDA program. Statistical analysis was performed with Student’s t test, Pearson’s r correlation coefficient, the Mann-Whitney non-parametric test and Spearman’s correlation coefficient when appropriate. Results: A strong correlation was found between the standard threshold perimetry indices and those of HRP. For the entire sample, the following significant correlations were found between the RDA index (DI) and all the HRP indices (p<0.001), and corrected pattern standard deviation (p<0.05), pattern standard deviation (p<0.01) and short-term fluctuation (p<0.05). No correlation was found with the mean deviation. Conclusions: The DI of HRP is theoretically capable of detecting localized dishomogeneity of retinal sensitivity. These data support this hypothesis. However, further studies are needed before this index can be applied clinically.