Comparison of global indices and test duration between two visual field analyzers: Octopus 300 and Topcon SBP-3000.

PURPOSE

To compare the global indices and test duration as measured by Octopus 300 and Topcon SBP-3000 perimeters. To our knowledge, this is the first study performed in this way.

METHODS

Eighty eyes of 40 glaucomatous and ocular hypertensive patients with previous perimetric experience had visual field tests with Octopus 300 (TOP strategy) and TOPCON SBP-3000. All pairs of tests were performed randomly on separate days, but within 1 month of each other. Taking into account reliability factors of both perimetric examinations, 54 eyes of thirty patients were eligible. Only one eye from each patient was considered. Mean sensitivity (MS), mean defect (MD), loss of variance (sLV-Octopus- and LV -Topcon-) and test duration times were considered.

RESULTS

A significant difference was found between the global indices and duration times of the Octopus and the Topcon perimeters (p < 0.05; Wilcoxon test). Moderate degrees of correlation were obtained for MS (Spearman's rho = 0.635; p < 0.001) and MD (Spearman's rho = 0.592; p = 0.001) measurements. There was no correlation between sLV and LV (Spearman's rho = 0.181; p = 0.337). Agreements between pairs of global indices were low as measured by concordance correlation coefficient.

CONCLUSION

Global indices measured by the Octopus and Topcon perimeters are significantly different, so direct comparison of the measured values is not reliable. Because of the poor association and agreement between values obtained by these two perimeters, indirect comparison is also inadvisable.