Purpose:
Visual field (VF) testing is often not performed in resource-poor settings due to lack of access to standard automated perimetry (SAP). Virtual reality (VR) perimetry headsets have been validated against SAP in recent studies, however the practicality of using these devices in the field is yet unmeasured1,2.
Methods:
We performed a prospective, observational study to evaluate the usability of a portable VR perimeter in resource-poor, outreach clinics where SAP is unavailable. Fifty-six adult patients from such ophthalmology clinics in Utah and Tanzania were included in the study. Inclusion criteria were based on random selection (n=23) and a known history, suspicion, or risk factors for glaucoma (n=33). VF testing was conducted by a technician using a head-mounted VR device with a smartphone-based software interface (C3 Fields Analyzer; Alfaleus, Vellore, India). Results were available to the examining ophthalmologist. After screening, patients and technicians answered an anonymous questionnaire about their experience via Likert scale (0 to 5). Physician impressions of test reliability, scotoma mapping, and clinical utility of results were also assessed.
Results:
Average patient response was 4.33±0.98 for device comfort, 4.53±0.76 for understanding of test instructions, 4.62±0.61 for ability to remain alert during the test, and 4.62±0.45 for willingness to retake the test. Technicians responded with average scores of 4.87±0.34 for ease of device setup, 4.89±0.31 for software usability, 4.91±0.35 for device portability, 4.79±0.49 for patient comfort, and 4.69±0.77 for impression of patient understanding. Physicians felt the test was reliable 79% of the time, that a true VF defect was seen 34% of the time, and that results helped make a diagnosis or management decision in 70% of cases. For patients in the glaucoma group only, these numbers were 74%, 53%, and 81%, respectively.
Conclusions:
Ophthalmologists found the VR VF results clinically useful, especially in cases of known or suspected glaucoma. The device was well-tolerated and easy to operate. Though SAP remains the gold standard for perimetry, our results suggest a possible role for VF testing with VR devices as a practical and convenient means of screening for and monitoring glaucoma in settings where standard automated perimetry is unavailable or impractical.

Celestine Gregerson: Commercial Relationship: Code N (No Commercial Relationship) | Trevor Annis: Commercial Relationship: Code N (No Commercial Relationship) | Michael Murri: Commercial Relationship: Code N (No Commercial Relationship) | Caleb Shumway: Commercial Relationship: Code N (No Commercial Relationship) | Jeff Pettey: Commercial Relationship: Code N (No Commercial Relationship) | Avni Shah: Commercial Relationship: Code N (No Commercial Relationship)