Comparison of Visual Parameters Between Normal Individuals and People with Low Vision in a Virtual Environment

Patients with Low vision are known to experience difficulties in executing activities of daily living and visual search due to reduction in vision. There is a need to translate clinical parameters into a real world that is relevant so as to understand the patient's functional vision; this can be possible with virtual reality (VR). This prospective study included 53 normal and 30 low vision subjects older than 18 years of age in a tertiary care center. The low vision subjects were further classified into peripheral field loss (PFL) and central field loss (CFL). A VR bank environment was developed with multiple tasks that aimed at assessing reading for distance and near, identification of objects against various contrast levels and mobility. Based on the normative data obtained a scoring system was developed to quantify the visual performance between normal and low vision subjects. A significant difference was found in the performance between the normal and low vision subjects in the VR environment. The overall VR performance score was lower in subjects with PFL 56.65 (IQR 19.4) than CFL 63.25 (IQR 10.83); however, both of them were lower compared with normal subjects 87 (IQR 4.6) p < 0.001. These findings suggest that performance of low vision subjects was worse than normal subjects in VR environment and it is important to plan and prioritize assessment and rehabilitation interventions for low vision subjects with a more holistic performance based approach.