24-2 SITA Standard versus 24-2 SITA Faster in Perimetry-Naive Normal Subjects

Abstract

Purpose: To compare the Swedish Interactive Thresholding Algorithm (SITA) Standard (SS) and SITA Faster (SFR) strategies in normal individuals undergoing standard automated perimetry (SAP) for the first time.

Design: Randomized, comparative, observational case series.

Participants: Seventy-four perimetry-naive healthy individuals.

Methods: All individuals underwent SAP 24-2 testing with the Humphrey Field Analyzer III (model 850 Zeiss) using the SS and SFR strategies. One eye of each individual was tested. Test order between strategies was randomized, and an interval of 15 minutes was allowed between the tests.

Main outcome measures: The following variables were compared: test time, foveal threshold, false-positive errors, number of unreliable tests, mean deviation (MD), visual field index (VFI), pattern standard deviation (PSD), glaucoma hemifield test (GHT), and number of depressed points deviating at P < 5%, P < 2%, P < 1%, and P < 0.5% on the total and pattern deviation probability maps. Specificity of the SS and SFR strategies were compared using Anderson's criteria for abnormal visual fields.

Results: The SFR tests were 60.4% shorter in time compared with SS (P < 0.001) and were associated with a significantly lower PSD (1.75 ± 0.80 decibel [dB] vs. 2.15 ± 1.25 dB; P = 0.016). There were no significant differences regarding the MD, VFI, foveal threshold, GHT, and number of points depressed at P < 5%, P < 2%, P < 1%, and P < 0.5% on the total deviation and pattern deviation probability maps between SS and SFR. When all exams were analyzed and any of Anderson's criteria was applied, the specificity was 68% with SFR and 61% with SS (P = 0.250). The specificities observed with SFR and SS when only the first or second exams were analyzed were also similar (63% vs. 64% and 72% vs. 58%, respectively, P > 0.05).

Conclusions: The SS and SFR were associated with similar specificities in perimetry-naive individuals. The SFR did not increase the number of depressed points in the total and pattern deviation probability maps. Ophthalmologists should be aware that both strategies are associated with disturbingly high false-positive rates in perimetry-naive individuals.

Financial disclosure(s): Proprietary or commercial disclosure may be found after the references.

Keywords: Automated perimetry; Glaucoma; Glaucoma diagnosis; Specificity; Visual field.