Clinical evaluation of SITA: a new family of perimetric testing strategies

Abstract 

· Purpose: To perform a clinical comparison of the Humphrey Full Threshold strategy with its intended replacement, SITA Standard, regarding testing time, reproducibility, and measured threshold sensitivity in normal subjects and glaucoma patients. · Methods: Thirty-eight healthy volunteers and 80 patients with primary open-angel glaucoma underwent central 30-2 testing with both Full Threshold and SITA strategies using a Humphrey HFA 2 Model 740 perimeter. The testing time, reproducibility, and measured threshold sensitivity of the two strategies were compared. · Results: The testing time for measurements with SITA was 56% lower in normal subjects and 45% lower in glaucoma patients than with Full Threshold. Cases having higher mean sensitivity or cases requiring longer testing time for Full Threshold had a greater percentage reduction in testing time for SITA. The test-retest variability studied in normal subjects was lower, but not significantly so, with SITA (2.9%) than with Full Threshold (3.4%). The mean sensitivities of SITA were higher (1 dB) than those of Full Threshold not only in normal subjects but also in glaucoma patients. This higher sensitivity in SITA was found irrespective of the order of the two tests both in normal subjects and claucoma patients. Analysis by each testing point revealed that the difference was not dependent on the test point position or the sensitivity at the point. · Conclusion: SITA has greater patient acceptability than the Full Threshold strategy. However, the difference in sensitivity can be considerable in a serial comparison of one patient’s fields tested by Full Threshold and SITA.