Hounsh Munshi, Kirsten da Silva, Elena Bitrian MD, Ta Chen Chang MD, Alana L Grajewski MD
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
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 Eye VRVF) utilizing a novel algorithm based on relevant physiological retinal nerve bundles to the SITA Standard algorithm used in Standard Automated Perimetry (SAP).
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 (VRVF) test (24-2, Size III) using the VRVF 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 (<30% false positives, false negatives, and fixation losses) on both VRVF 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.
From the 80 eyes identified, an ICC of 0.89 (95 % CI = 0.79 – 0.95; p < 0.0001) was calculated from the respective mean sensitivities of the VRVF Standard and the SITA Standard algorithms. A Bland-Altman plot revealed a mean difference of 0.27 dB and standard deviation of ±3.36 dB, with upper and lower limits of agreement of 6.87 dB and -6.33 dB, respectively.
ICC showed excellent agreement between VRVF Standard strategy 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. VRVF 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.
