Comparison of Perimetric Outcomes from a Tablet Perimeter, Smart Visual Function Analyzer, and Humphrey Field Analyzer

Abstract

Purpose: The tablet-based Melbourne Rapid Fields (MRF) visual field (VF) test and the IMOvifa Smart Visual Function Analyzer (SVFA) are portable perimeters that may allow for at-home monitoring and more frequent testing. We compared tablet and SVFA results with outputs from the Humphrey Field Analyzer (HFA) 24-2 Swedish Interactive Threshold Algorithm Standard program.

Design: Observational cross-sectional study.

Subjects: Adult participants with a diagnosis of glaucoma, suspected glaucoma, or ocular hypertension seen in the Massachusetts Eye and Ear glaucoma clinic were enrolled. All participants were reliable and experienced HFA testers.

Methods: Participants were tested with the SVFA and HFA. The study staff also trained participants on the MRF tablet with instructions to take weekly tests at home for 3 months. Visual field results from the 3 devices were compared.

Main outcome measures: Mean deviation (MD), pattern standard deviation (PSD), reliability parameters, and point sensitivity.

Results: Overall, 79 participants (133 eyes) with a mean age of 61 ± 13 years (range, 26-79 years) were included; 59% of the participants were female, and the mean HFA MD was -2.7 ± 3.9 dB. The global indices of MD and PSD did not significantly vary between HFA and the 2 novel devices, except that the tablet VF reported a 0.6 dB higher PSD compared with HFA. However, tablet and SVFA sensitivities significantly differed from those of the HFA at 36 and 39 locations, respectively, out of 52 locations. Relative to HFA, the tablet overestimated light sensitivity in the nasal field while underestimating the temporal field. The SVFA generally underestimated light sensitivity, but its results were more similar to HFA results compared with the tablet.

Conclusions: Although average MD values from the 2 novel devices suggest that they provide similar results to the HFA, point-by-point comparisons highlight notable deviations. Differences in specific point sensitivity values were significant, especially between the tablet and the other 2 devices. These differences may in part be explained by differences in the devices' normative databases as well as how MD is calculated. However, the tablet had substantial differences based on location, indicating that the tablet design itself may be responsible for differences in local sensitivities.

Financial disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Keywords: At-Home Monitoring; Glaucoma; Perimetry; Telemedicine; Visual field.