Optical Coherence Tomography Analysis of International Space Station Astronauts

Abstract

Purpose : The aim of this study was to examine astronaut retinal nerve fiber layer (RNFL) changes with optical coherence tomography (OCT).

Methods : Cirrus HD-OCT (Zeiss, Germany) scans were conducted on NASA astronauts in the International Space Station. Astronauts that underwent bilateral preflight, inflight and postflight OCT scans between 2013-2020 were included in our study. De-identified data including astronaut flight duration, OCT scans and age at mission launch was provided by the NASA Lifetime Surveillance of Astronaut Health (LSAH). Analysis of statistics was conducted in Microsoft Excel (California, USA).

Results : 102 OCT scans were analyzed from 34 astronaut eyes. Mean astronaut time in orbit was 190 ± 52 days. Mean astronaut age was 48.2 ± 5.5 years. Average RNFL thickness significantly increased after LDSF (106.6μm vs. 108.7μm, +2.1μm). Temporal superior segment (126.5μm vs. 129.3μm, +2.8μm), and nasal inferior segment RNFL thickness (124.7μm vs. 129.0μm, +4.3μm) also significantly increased postflight.

Conclusions : Average RNFL was increased after LDSF. Further research is required to assess the impact on astronaut visual function and stratify astronauts based on spaceflight associated neuro-ocular syndrome (SANS) status.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.