Ocular complaints and diagnoses in spaceflight

The NASA human system risk board (HSRB) has long focused on trauma and acute medical illness as a key contributor to high-level in-flight medical risk. However, ocular issues, trauma, and complaints during spaceflight are poorly characterized. In a retrospective case series, the NASA data from the life sciences data archive (LSDA) and the lifetime surveillance of astronaut health (LSAH) was queried for eye-related complaints and conditions in spaceflight across international space station (ISS) missions and space shuttle (STS) missions. The ISS dataset included missions from the year 2000 to 2020, and the STS dataset included missions from 1981 to 2011. Data were reviewed and segmented into categories of ocular complaints. 135 STS missions and 63 ISS missions were included in this analysis. Ocular events were only noted across 83 STS missions (61.5%) and 41 ISS missions (65.1%). Overall, the most common ocular complaints were eye irritation (n = 80, 33.1%), ocular foreign body or foreign body sensation (n = 55, 22.7%), dry eye syndromes (n = 38, 15.7%), epiphora or excessive tearing (n = 19, 7.85%). Of all ocular complaints or diagnoses, 9 (3.72%) were considered higher severity (keratitis, corneal ulcer, chemical exposure, and corneal abrasion). However, seemingly none required evacuation from mission. Improved depiction of ocular symptoms and diagnoses, and a more standard classification system and process to describe ocular symptoms, diagnoses, and treatments in space is crucial to provide more effective and comprehensive treatments.