Comparison of portable perimetry tests with the Humphrey Field Analyzer

Abstract

Purpose : The tablet-based Melbourne Rapid Fields (MRF) visual field (VF) test (M&S Technologies, Niles, IL, USA) and IMOvifa virtual reality (VR) VF test (CREWT Medical Systems, Inc., Tokyo, Japan) are portable VF tests that may allow for at-home monitoring and more frequent testing. We compared MRF and IMOvifa outputs to the Humphrey Field Analyzer (HFA) 24-2 Swedish Interactive Threshold Algorithm Standard program.

Methods : In a pilot observational study, subjects who were glaucoma suspects or had a prior glaucoma diagnosis took IMOvifa and MRF tests. All subjects were reliable, experienced HFA testers. We built density plots of average mean deviation (MD) and pattern standard deviation (PSD) and compared MD and PSD group means of each novel device to the HFA. We used paired t-tests to compare sensitivities of 54 corresponding locations from HFA 24-2 also tested on the new devices.

Results : For 50 subjects with an average age of 61 years (range 30-79), MD and PSD for all three devices were not significantly different (MD: HFA vs. IMOvifa CI=[-0.30 to 1.38], p=0.205; HFA vs. MRF CI=[-0.75 to 0.93], p=0.837; PSD: HFA vs. IMOvifa CI=[-0.05 to 1.18, p=0.070]; HFA vs. MRF CI=[-0.65 to 0.57], p=0.905). MRF sensitivities differed from those of HFA at 28 locations, while 23 locations differed for IMOvifa versus HFA. MRF reported greater point sensitivity in the nasal field versus HFA but lower sensitivity in the temporal field. IMOvifa generally reported lower sensitivity versus HFA.

Conclusions : While average MD similarities between the novel devices and the HFA suggest they provide similar results, point-by-point comparisons indicate significant differences. Peripheral point sensitivity differences between MRF and HFA may be related to MRF’s flat tablet format versus HFA’s spherical bowl format. The IMOvifa had a small bias throughout the field. The small sample size and calculation of MD as a weighted average toward the VF center may explain the lack of difference in MD despite many mostly peripheral differences in sensitivity between each novel device and the HFA.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.

 

Figure 1: Density plots comparing the HFA, IMOvifa, and MRF values for MD and PSD. Vertical lines denote interquartile range and median.

 

Figure 2: Point by point analysis of sensitivities at each testing location comparing (a) HFA and IMOvifa and (b) HFA and MRF. Locations and degrees of significantly different values are shown (all eyes plotted as right eye).