Spaceflight Associated Neuro-ocular Syndrome (SANS) Diagnostic Devices: Mini Optical Coherence Tomography (OCT)

Optical Coherence Tomography (OCT) is a non-invasive diagnostic technique that renders an in vivo cross-sectional view of the retina. OCT is used terrestrially in optometry and ophthalmology clinics as a diagnostic tool.

Spaceflight Associated Neuro-ocular Syndrome (SANS) is an important spaceflight risk that NASA is studying to better understand if mitigation strategies are necessary during long duration spaceflight. SANS includes a constellation of signs and symptoms including optic disc edema, globe flattening, choroidal and retinal folds, and hyperopic shifts. OCT is the primary imaging modality used by experts to measure changes in the retina during spaceflight. There is currently an OCT device on ISS that allows for in-mission measurements. However, this device is large in mass and volume, which introduces limitations in its use for exploration missions. Therefore, a Mini OCT device is being developed that is significantly smaller and lighter than the current technology for use in lunar and Mars missions. An ISS deployment of the Mini OCT is planned for 2027.

Compared to the state-of-the-art OCT device currently used on ISS, a Mini OCT device will significantly reduce overall mass and volume of the technology. The Mini OCT will also minimize crew time needed for training and operations. Currently it takes two crewmembers to perform an OCT in-flight. The Mini OCT device would require only the crewmember undergoing the exam. Furthermore, the Mini OCT does not require eye dilation, which has significant impacts to the crew timeline currently. Mini OCT will help clinicians prescribe and tailor SANS countermeasures and treatments currently being investigated. An ISS technical demonstration of this device is planned as part of NASA’s testing strategy.