Technicians Can Remotely Monitor Multiple Visual Fields Tests Simultaneously

Technicians can successfully monitor up to 2 patients simultaneously who are undergoing evaluation with a remote visual field (VF) test, according to research published in the Journal of Glaucoma. 

The technicians were reliably able to instruct patients using audio/visual a remote monitoring system to derive results from both Swedish Interactive Testing Algorithm (SITA) Standard 24-2 and SITA Faster 24-2C exams.

This remote monitored VF test could provide an opportunity for patients to continue receiving scheduled visual field tests, while maintaining distance in response to situations such as the COVID-19 pandemic, according to the study. “Efforts to provide more efficient and safer testing conditions using remote, simultaneous VF supervision can be implemented without significant decrease in average VF performance or reliability,” researchers say.

This prospective interventional case series took into account 861 eyes of 474 patients (mean age 64.4±15.7, 250 women) who underwent a combined total of 757 VFs performed with SITA Standard 24-2 (615 single tests, 142 simultaneous tests) and 104 performed with SITA Faster 24-2C (88 single tests, 16 simultaneous) at the Massachusetts Eye and Ear glaucoma clinic between January 2021 and July 2021. 

The participants were required to complete automated perimetry assessments alone in a room that was monitored using the video/audio recordings. Technicians monitored 1 or 2 evaluations simultaneously, depending on the availability of participants at that time. Researchers compared the results of single and simultaneous remotely monitored perimetry for false negatives, false positives, fixation losses, mean deviation, pattern standard deviation, visual field (VF) index, and test duration. Additional traditional in-room testing completed in the 8 months prior to the study was used as a comparison to the video/audio monitoring system used in this study.

Researchers found that performance and reliability parameters were essentially identical whether the technician was monitoring a single test or 2 simultaneous tests. However, the study does point to some significant differences. For instance, fixation losses in SITA Standard 24-4 VFs were greater (single 16.8±19.7%, simultaneous 22.5±25.0%, P =.01). The researchers speculate that technicians may have been “delayed in identifying fixation losses when monitoring 2 patients and therefore intervened slightly later in the test.”

No other significant differences were found between single and simultaneous VF results for either the SITA Standard 24-2 or the SITA Faster 24-2C.

Researchers noted a decrease in fixation loss between traditional and remote exams overall(traditional: 23.6±27.5%, remote 17.7±20.8%, P =.003).

Researchers report that the fixation losses identified in this study are not likely to impact the overall results of the VF assessment and therefore are not concerning. Utilizing the remote monitoring framework would allow for VF testing to continue regardless of the status of the COVID-19 pandemic and simultaneous testing allows for technicians to effectively assess a higher volume of patients when necessary, according to the report.

The limitations of this study include the inter-technician variability of simultaneous testing results, which is likely due to lowered comfort levels of technicians when completing testing simultaneously, and the low number of SITA Faster 24-2C tests completed, skewing the analysis of failed tests. Additionally, the learning effect may have impacted results as all patients had completed VF testing at least once prior to study. 

Reference

Meshkin RS, Zhao Y, Elze T, Boland MV, Friedman DS. Remote video monitoring of simultaneous visual field testing. J Glaucoma. 2022;31(7):488–493. doi:10.1097/IJG.0000000000002045