SITA standard in optic neuropathies and hemianopias: A comparison with full threshold testing

PURPOSE. To compare visual sensitivity, fatigue effect, and probability plo t data between Full Threshold (FT) Humphrey automated perimetry and Swedish Interactive Threshold Algorithm (SITA) standard strategies in patients wit h optic neuropathies and hemianopias. METHODS. Twenty-four patients with nonglaucomatous optic neuropathies and 1 8 patients with a relative homonymous or bitemporal hemianopia were tested with both conventional perimetry (Humphrey 24-2 program) and "back to back" SITA standard tests (SITA 1, SITA 2) to approximate the test time of the F T test conditions. Also, 28 normal subjects between the ages of 20 and 80 w ere tested with this protocol. The visual field quadrants with the most dam age were used to evaluate any fatigue effect (i.e., possible lack of fatigu e effect with SITA standard due to the shorter test time) and to compare pr obability plot data between FT, SITA 1, and SITA 2. Pointwise total and pat tern deviation probability plot defects were weighted by degree of signific ance and summed. RESULTS. Test times for normal subjects were 45 seconds longer for FT than for the combined test time of SITA 1 + SITA 2. Patients' test times were 40 seconds longer for hemianopias and 90 seconds longer for optic neuropathie s with FT than the combined times for two SITA tests. There were higher sen sitivities found with SITA 1 compared with Full Threshold (1.06 dB, P < 0.0 01) and SITA 2 with Full Threshold (0.73 dB, P < 0.001) in the most damaged quadrant for the optic neuropath) patients; for the hemianopia patients th e difference in values were between SITA 1 and Full Threshold (0.96 dB, P = 0.07 and between SITA 2 and Full Threshold (0.11 dB, P = 0.87). The second SITA standard test had lower sensitivity than the first SITA standard test by 0.82 dB in hemianopias and by 0.71 dB in optic neuropathy patients. Ana lysis of the total and pattern deviation probability plot data showed sligh tly more defects (number and magnitude) with SITA 1 compared to FT for both groups, but the differences were not statistically significant. CONCLUSIONS. Sensitivities were higher in patients with hemianopias or opti c neuropathies using SITA standard compared with FT by approximately 1 dB. The probability plot comparison suggests SITA standard is at least as good as FT for detection of visual loss in individual examinations. However, eff icacy of SITA standard for serial examinations has not yet been evaluated.