Pilot comparison of monocular and binocular modes of virtual reality field testing in strabismus

Virtual reality field (VRF) perimetry is a promising new tool for visual field assessments, offering both monocular and binocular testing modes. We aimed to examine whether ocular misalignment, known as strabismus, influences VRF outcomes between monocular and binocular testing modes, which is currently unknown. Children with non-amblyopic horizontal strabismus were enrolled and completed VRF testing (Olleyes VisuALL) in either the game-based or standard Humphrey visual field (HVF)-equivalent algorithm. Within their respective algorithms, participants completed tests in both monocular and binocular modes. Analyzed parameters included mean deviation (MD), pattern standard deviation (PSD), and foveal sensitivity (FS). Additionally, a masked ophthalmologist graded whether the VRF was abnormal. Twenty-two children (44 eyes) were enrolled with a mean age of 12.1 ± 2.7 years. Regarding MD, participants who took the game-based algorithm compared to the HVF-equivalent yielded better scores (P = 0.048). For PSD, older participants exhibited better scores than younger participants (P = 0.038). Binocular and monocular mode testing were similar across all parameters, and yielded equal rates of abnormal test results (22.7% vs. 22.7%; P = 1.00). Overall, non-amblyopic horizontally strabismic children demonstrated comparable VRF outcomes in both monocular and binocular testing modes, suggesting similar utility between exam options.