Visual function impairment in patients suffering from visually induced motion sickness. A preliminary observational longitudinal study

Objective: Visually induced Motion Sickness (VIMS) is a side effect induced by the physical motion of the person or visual motion that adversely affects otherwise individuals and decreases safety in situations that require high levels of concentration. The exact mechanisms behind the emergence of VIMS are still unknown but can be triggered by direct or indirect stimuli due to mismatches in the visual-vestibular autonomic pathways. The aim of this preliminary study was to explore the presence of visual dysfunctions in patients suffering from VIMS and then evaluate the potential role of a customized visual training (VT) on their perceived sickness symptoms. Methods: A total of 9.675 medical records of patients who referred motion sickness were reviewed; 455 patients with a diagnosis of VIMS were included. A total of 95 patients (86 females and 9 males, mean age of 37,68 ± 9.20 years) met the inclusion criteria and were enrolled in this study. Two evaluation sessions were carried out immediately before (T0) and after 16 weeks (T1) of visual training (VT). The main goal of VT was to facilitate the visual center-periphery integration. VT was performed 1 day/week/16 weeks under therapist supervision in the Optometric centre and 5 days/week/16 weeks at home without supervision. Results: The within-subjects comparison at times T0–T1 showed significant improvement of the symptoms in all the included patients. Conclusion: Our results support the hypothesis that patients suffering from VIMS may present also a visual function impairment that can increase the dizziness-related symptoms. Furthermore, visual training can help patients with VIMS and visual dysfunction in reducing capture discomfort, stomach awareness, and nausea.