A Multi-Modal Visual Assessment System For Monitoring Spaceflight Associated Neuro-Ocular Syndrome (SANS) During Long Duration Spaceflight

Abstract

Spaceflight Associated Neuro-Ocular Syndrome (SANS) refers to a unique collection of neuro-ophthalmic clinical and imaging findings that are observed in astronauts during long duration spaceflight. These findings include optic disc edema, posterior globe flattening, retinal nerve layer fiber thickening, optic nerve sheath distension, and hyperopic shift. SANS currently serves as a large barrier to deep space exploration; however, the exact pathophysiology is still being investigated. While in-flight imaging exists on the International Space Station, there are limitations to constant monitoring. To efficiently document the subtle changes that occur in SANS, NASA has funded the development of a head-mounted display, multi-modal visual assessment system; this novel device integrates visual acuity, visual field, contrast sensitivity, and metamorphopsia data (indirect indications) with known terrestrial neuro-ophthalmic imaging (direct indications) from astronauts and terrestrial analogs. By mapping these two indications, this visual assessment device will provide rapid in-flight monitoring of SANS symptoms and provide tools for the terrestrial development of countermeasures. We are in the process of beginning a pilot study of this multi-modal visual assessment device in healthy subjects to investigate the validity and reliability of this novel technology. This foundational study will compare the system with standard vision assessments utilized in clinical practice.