Initial mobility behaviors of people with visual impairment in a virtual environment using a mixed methods design

Abstract

Visual impairment (VI) can result from many different ocular diseases and is defined as the poor functioning of the visual system. To describe the extent of VI, clinical measures of visual function are used, which include visual acuity (VA), visual field (VF) and contrast sensitivity (CS). When there is a reduction in any of these visual functions, safe and efficient mobility is one such activity that may be compromised. While there is currently no cure for VI-causing retinal diseases such as retinitis pigmentosa (RP), age-related macular degeneration (AMD) and glaucoma, gene therapy is gaining traction as a possible treatment. Preliminary results have shown that patients have performed significantly better on mobility tasks, such as the navigation of an obstacle course, post-treatment. Interestingly, visual function measures have not always shown such significant improvement. It is therefore important to develop a standardized obstacle course that can assess therapy efficacy, as the drawbacks of current physical orientation and mobility obstacle courses include high cost of set-up, potential dangers to participants and the fact that performance may reflect non-visual abilities such as physical fitness. To address these concerns, we have investigated the use of a virtual obstacle course in people with visual impairment. Here we report the initial behaviors and strategies of people with visual impairment as they navigate through four obstacle tasks using a virtual reality headset.