Eye Health: Preliminary Retrospective Validation of a New Virtual Reality Visual Field Standard Testing Algorithm, as Compared to Standard Automated Perimetry
Website: https://virtualvision.health/research/
Conference: The Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting 2022
Purpose: Visual field testing is a pillar of glaucoma diagnosis and management, though it requires an in-person patient visit, a designated space, and a skilled technician to administer the test. This study aims to compare a portable Virtual Reality Visual Field device (Virtual Vision) utilizing a novel algorithm based on relevant physiological retinal nerve bundles to the SITA Standard algorithm used in Standard Automated Perimetry (SAP).
Methods: A retrospective chart review of glaucoma patients seen at a tertiary care clinic between March and July 2021 was conducted. Eligible patients had a Virtual Reality Visual Field test (24–2, Size III) using the Virtual Reality Visual Field Standard strategy algorithm, and at least 2 previous SAPs (24–2, Size III) using SITA Standard, taken within 4 years of the most recent visit, with good reliability (false positives, false negatives, and fixation losses) on both Virtual Reality Visual Field and SAP. The mean light sensitivity threshold values from the first eye tested for each patient were compared between the 2 algorithms using an intraclass correlation analysis (ICC) and a Bland-Altman plot.
Results: From the 40 patients identified, 10 were excluded due to poor reliability, or inconsistent stimulus size or testing strategy. Of the remaining 30 patients, an ICC of 0.89 (95 % CI = 0.79–0.95; p < 0.0001) was calculated from the respective mean sensitivities of the Virtual Reality Visual Field Standard and the SITA Standard algorithms. A Bland-Altman plot revealed a mean difference of 0.27±3.36, with upper and lower limits of agreement of 6.87 and -6.33, respectively.
Conclusion: ICC showed excellent agreement between Virtual Vision’s Virtual Reality Visual Field Standard and SITA Standard algorithms, suggesting that this novel algorithm is a promising tool in perimetric testing in glaucoma patients. Although the Bland-Altman plot showed wide limits of agreement, the data was normally distributed around a low mean difference, reflecting the accepted variability of visual field testing. Virtual Reality Visual Field Standard detects mean sensitivities with significant correlation to SAP SITA Standard and may accurately be used as an alternative to SAP for visual field testing in glaucoma patients.
Investigation Location: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL
Conference: The Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting 2022
Investigators: Hounsh Munshi, Kirsten da Silva, Elena Bitrian MD, Ta Chen Chang MD, Alana L Grajewski MD
