Ocular complaints and diagnoses in spaceflight

Area of Science:

• Space Medicine
• Ophthalmology
• Aerospace Medicine

Background:

• The NASA Human System Risk Board (HSRB) traditionally prioritizes trauma and acute illness for in-flight medical risk.
• Ocular issues, trauma, and complaints during spaceflight remain poorly characterized, despite their potential impact on astronaut health and mission success.

Purpose of the Study:

• To retrospectively analyze and characterize ocular complaints and conditions experienced by astronauts during space shuttle (STS) and International Space Station (ISS) missions.
• To identify the most common ocular issues encountered in spaceflight and assess their severity.

Main Methods:

• A retrospective case series analysis of ocular complaints was conducted using data from NASA's Life Sciences Data Archive (LSDA) and Lifetime Surveillance of Astronaut Health (LSAH).
• Data from 135 STS missions (1981-2011) and 63 ISS missions (2000-2020) were reviewed and categorized.
• Ocular events were identified across 61.5% of STS missions and 65.1% of ISS missions.

Main Results:

• The most frequent ocular complaints included eye irritation (33.1%), foreign body sensation (22.7%), dry eye syndromes (15.7%), and excessive tearing (7.85%).
• A small percentage (3.72%) of ocular events were classified as higher severity, including keratitis, corneal ulcer, chemical exposure, and corneal abrasion.
• No higher severity ocular events necessitated mission evacuation.

Conclusions:

• Ocular complaints are a significant component of medical events during spaceflight, with common issues like irritation and foreign bodies frequently reported.
• There is a critical need for improved documentation of ocular symptoms and diagnoses, alongside a standardized classification system for spaceflight ophthalmology.
• Standardization will facilitate more effective and comprehensive medical treatments for astronauts, enhancing overall mission safety and crew well-being.