The SITA perimetric threshold algorithms in glaucoma.

Purpose: To determine the within-visit between-algorithm and the within-algorithm between-visit differences in sensitivity for the SITA Standard, SITA Fast, FASTPAC, and Full Threshold algorithms in stable primary open angle glaucoma.
Methods: One designated eye from each of 29 patients (age 67.3 +/- 10.2 years; mean +/- SD) experienced in automated perimetry was examined with the four algorithms on each of three visits, using the Humphrey Field Analyzer 750 and Program 30-2.
Results: The group mean Mean Sensitivity was 1.0 dB greater for SITA Standard than Full Threshold (P < 0.001), 0.7 dB greater for SITA Standard than FASTPAC (P < 0.001), 1.6 dB greater for SITA Fast than FASTPAC (P < 0.001), and 0.9 dB greater for SITA Fast than SITA Standard (P < 0.001). The higher pointwise sensitivity for SITA Fast compared to Full Threshold, FASTPAC, and SITA Standard increased with increase in defect depth. The examination duration for SITA Standard was 53% of that for Full Threshold and 50% shorter for SITA Fast compared to FASTPAC (P < 0.001), regardless of age (P = 0.932). The examination duration increased with increase in severity of field loss (P < 0.001), and this increase was proportionately greater for both SITA algorithms (P < 0.001), particularly SITA Fast. The Total and Pattern Deviation probability analyses of both SITA algorithms yielded a statistically greater defect than Full Threshold or FASTPAC (P < 0.001). The within-algorithm between-visit differences were similar between SITA Standard and Full Threshold and between SITA Fast and FASTPAC.
Conclusions: Both SITA algorithms produce a marginally higher differential light sensitivity compared to existing algorithms but with a statistically deeper defect and a marked reduction in examination duration.