Ocular Biomechanical Responses to Long-Duration Spaceflight

Marisse Masis Solano; Remy Dumas; Mark R Lesk; Santiago Costantino

doi:10.1109/OJEMB.2024.3453049

Ocular Biomechanical Responses to Long-Duration Spaceflight

IEEE Open J Eng Med Biol. 2024 Sep 5:6:127-132. doi: 10.1109/OJEMB.2024.3453049. eCollection 2025.

Authors

Marisse Masis Solano^{1

2}, Remy Dumas¹, Mark R Lesk^{1

2}, Santiago Costantino^{1

2}

Affiliations

¹ Maisonneuve-Rosemont Hospital Research Center Montreal QC H1T 2M4 Canada.
² University of Montreal Montreal QC H3T 1J4 Canada.

Abstract

Objective: To assess the impact of microgravity exposure on ocular rigidity (OR), intraocular pressure (IOP), and ocular pulse amplitude (OPA) following long-term space missions. OR was evaluated using optical coherence tomography (OCT) and deep learning-based choroid segmentation. IOP and OPA were measured with the PASCAL Dynamic Contour Tonometer (DCT). Results: The study included 26 eyes from 13 crew members who spent 157 to 186 days on the International Space Station. Post-mission results showed a 25% decrease in OPA (p < 0.005), an 11% decrease in IOP from 16.0 mmHg to 14.2 mmHg (p = 0.04), and a 33% reduction in OR (p = 0.04). No significant differences were observed between novice and experienced astronauts. Conclusions: These findings reveal previously unknown effects of microgravity on the eye's mechanical properties, contributing to a deeper understanding of Spaceflight-Associated Neuro-ocular Syndrome (SANS). Long-term space missions significantly alter ocular biomechanics and have the potential to become biomarkers of disease progression.

Keywords: Microgravity; ocular rigidity; space biomechanics; spaceflight.

Grants and funding

This work was supported in part by CSA, in part by CIHR, in part by FRQS, in part by NASA, in part by the Canadian Space Agency, and in part by the Canadian Institutes of Health Research.