Brain Stimulation Effects on Orientation and Mobility Skills in Adults With Vision Impairment

This pilot clinical trial evaluates whether non-invasive brain stimulation improves the orientation and mobility (O\&M) skills of individuals with constricted visual fields in both eyes. The study is composed of three visits. The first visit is meant to confirm eligibility by performing a few clinical tests. Eligible participants will then complete two additional visits, one in which the participants receive active stimulation, and one in which the participants receive placebo (sham) stimulation. Stimulation will be administered in a randomized, double-blind order. To evaluate improvement, various measures of O\&M performance will be assessed on a standardized obstacle course featuring static natural and artificial obstacles at defined intervals after the intervention. We hypothesize that the application of hf-tRNS to V1 will improve the orientation and mobility skills of individuals with constricted visual fields immediately following stimulation as a results of enhanced periphery through modulation of the mechanisms responsible for crowding, thereby reducing crowding effects and improving contrast for individuals with rod-cone dystrophy and RP (genetic conditions), whereas for individuals with glaucoma (a neurogenerative condition), any improvement noted would be attributed to be enhanced processing of visual signal in the affected periphery. The results will inform the design of a future, larger-scale study.