Clinical evaluation of a new perimetric testing algorithm, SITA Faster

Abstract

Purpose : A new test algorithm has been developed for the Humphrey perimeter called SITA Faster (SFR). SFR is a modification of SITA Fast (SF) and was designed to further reduce test time. The purpose of the present study was to compare the results of SITA Faster with those of SF and SITA Standard (SS).

Methods : 126 eyes with manifest or suspect glaucoma of 126 patients underwent 24-2 threshold perimetry with SFR, SF and SS in randomized order, with tests repeated in reversed order at a 2^nd visit. Five centers, Berkeley CA USA, Hong Kong China, Malmö Sweden, Tajimi Japan, and Tampere Finland participated. Results were pooled and analyzed in terms of test time, VFI, MD, and number of significantly depressed test points in total (TD) and pattern deviation (PD) probability maps. Test-retest variability was also studied.

Results : We analyzed results from 125 eyes; one outlier was excluded. Mean test times were 2 min 59 sec, 4 min 7 sec, and 6 min 9 sec for SFR, SF & SS. SFR thus reduced average test time by 30.4% and 53.5% compared to SF & SS. Test times for all 3 algorithms were shorter in normal and minimally damaged fields than in fields having higher levels of field loss (Fig. 1). Mean MD values were not significantly different, at -8.48 dB, - 8.42 dB and -8.48 dB for SFR, SF and SS. Mean VFI values for SFR and SF were identical at 77.1%, while that of SS was slightly worse at 75.9% (p=0.003). There were no significant differences between SFR & SF in the number of significantly depressed test points in TD or PD probability maps. Intervisit R² for the number of TD <5% or worse significant points did not differ significantly between SFR & SF (0.87 vs 0.88), and R² between SFR & SF TD significant points was 0.86. Test–retest threshold variabilities were similar, generally with overlapping confidence limits, but with slightly higher SFR variability in severly depressed test points, and slightly lower SFR variability in points with higher sensitivity (Fig. 2).

Conclusions : SITA Faster saved considerable test time as compared to SF & SS. SITA Faster test results were similar to those of SF. SITA Faster’s rather small differences compared to SS were similar to those seen between SF and SS. SITA Faster provides a new time-saving alternative for SAP threshold testing.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.

 

Fig. 1 Test durations vs stage of glaucoma

 

Fig. 2 Pointwise threshold variability with 95% confidence limits vs threshold