Virtual Reality-Based Dichoptic Therapy in Acquired Brain Injury: Functional and Symptom Outcomes

Abstract

Background: Acquired brain injury (ABI) often disrupts binocular vision, causing deviations on the cover test and reduced stereopsis that impair functional visual performance. This study investigated the effects of a dichoptic vision therapy protocol—based on an immersive virtual reality (VR) system—on visual field parameters, oculomotor reaction times, and self-reported visual symptoms in adults with ABI. Methods: In a controlled parallel-group design, adult ABI patients (median age 51 years) were assigned to an experimental group (dichoptic VR therapy) or a control group. Six sessions of visual therapy were performed. Primary outcomes included perimetric visual field indices and oculomotor reaction times; the secondary outcome was the Brain Injury Vision Symptom Survey (BIVSS) score. Etiology (stroke vs. traumatic brain injury) was recorded. Results: No statistically significant improvements were found in perimetric visual field indices (p > 0.05), except for a slight gain in the top-right quadrant in the experimental group. Reaction times did not differ significantly between groups. However, the experimental group reported a greater reduction in visual symptoms as measured by the BIVSS. Patients with traumatic brain injury exhibited better functional improvement, particularly in the top-left quadrant (p = 0.04). Conclusions: Dichoptic VR-based therapy did not restore perimetric field losses in ABI patients but reduced visual symptoms and may enhance functional adaptation of residual vision rather than structural recovery. The therapeutic response varied by etiology, favoring traumatic brain injury. Larger, longer trials integrating objective and subjective measures, including neuroimaging, are warranted.