The case for anterior segment optical coherence tomography (AS-OCT) for the international space station and future planetary spaceflight: Clinical relevance and technical implementation.

Spaceflight presents unique challenges to ocular health which must be addressed when considering future long-term missions to Mars and beyond, specifically with increased risk to the anterior segment of the eye. While the posterior segment has been heavily researched via examinations with Heidelberg's Spectralis Optical Coherence Tomography (OCT)2 Module aboard the International Space Station (ISS), evaluation of the anterior segment is not as extensively performed. Despite the capabilities of the Spectralis, which allows for anterior segment imaging via the Anterior Segment Module (ASM), transforming the OCT into an Anterior Segment OCT (AS-OCT), there is limited information available regarding anterior segment effects due to microgravity and spaceflight.

The ocular surface during spaceflight: Post-mission symptom report, extraterrestrial risks, and in-flight therapeutics.

Ocular health is critical for overall astronaut health requirements given its essential role for mission performance and safety. The ocular surface is a vital structure to the visual system and is essential for ocular protection and the refraction of light for focused vision. Data from the 2024 NASA Lifetime Surveillance of Astronaut Health identified that Space Shuttle and International Space Station (ISS) astronauts (N = 257) queried during post-flight eye exams reported symptoms of eye irritation (34 %), dry eyes (14 %), and foreign body sensation (21 %).

Corneal Edema and the Endothelium in Spaceflight.

Introduction: With future manned missions that extend beyond low Earth orbit, it would be wise to anticipate all risks to astronaut health, including those relevant to ophthalmology and the ocular surface. Corneal edema has been documented among mice experiments conducted onboard the Space Transportation System mission, STS-133, owing to increased stress response gene expression.

Methods: A targeted, relevant search of the literature on topics relating to ocular surface and spaceflight was conducted with scholarly databases PubMed, Web of Science, and Embase from inception to July 2024.

Ocular trauma in microgravity: In-flight diagnostics and extraterrestrial strategies for management.

Long-duration spaceflight missions (including the International Space Station [ISS]) are in one of the most remote and harsh environments humans live and work in. Medical emergencies in space are even more complicated in an already high-risk environment. Despite training, ISS crewmembers face many challenges in diagnosing and managing disease with limited diagnostic capability and equipment on the ISS, restricted medication availability, delayed access to medical professionals; and the latency of space missions.

Defining spaceflight associated dry eye syndrome (SADES): Mechanisms, complications, and countermeasures.

There is a high prevalence of dry eye-related symptoms among astronauts during spaceflight. We propose naming this phenomenon: Spaceflight Associated Dry Eye Syndrome (SADES). In this study, we review the potential mechanisms of dry eye in the spaceflight environment, categorizing them into external (radiation, environmental hazards) and microgravity-related (meibum outflow) mechanisms.

Risk of Permanent Corneal Injury in Microgravity: Spaceflight-Associated Hazards, Challenges to Vision Restoration, and Role of Biotechnology in Long-Term Planetary Missions.

Human space exploration presents an unparalleled opportunity to study life in extreme environments-but it also exposes astronauts to physiological stressors that jeopardize key systems like vision. Corneal health, essential for maintaining precise visual acuity, is threatened by microgravity-induced fluid shifts, cosmic radiation, and the confined nature of spacecraft living environments. These conditions elevate the risk of corneal abrasions, infections, and structural damage.

Potential Risks of Ocular Molecular and Cellular Changes in Spaceflight.

Purpose: Many fundamental cellular and molecular changes are known to occur in biological systems during spaceflight, including oxidative stress, DNA damage, mitochondrial damage, epigenetic factors, telomere lengthening, and microbial shifts. We can apply the consequences of these molecular changes in ocular cells, such as the retinal ganglion cells and corneal epithelium, to identify ophthalmologic risks during spaceflight. This review aims to discuss the potential molecular changes in greater detail and apply the principles to ocular cells and ophthalmic disease risk in astronauts.

Management of corneal injuries in spaceflight and recommendations for planetary missions.

In February 1968, NASA purchased 400 antigravity ballpoint pens from the Fisher Pen Company for the Apollo Program to prevent potential harm to astronauts and equipment. Mechanical pencils previously used in microgravity posed risks like eye injuries from floating fragments penetrating the cornea. The cornea is vulnerable to abrasions, perforations, and chemical burns in such environments, affecting crewmembers aboard the International Space Station (ISS).

Oculomics: Current concepts and evidence.

The eye provides novel insights into general health, as well as pathogenesis and development of systemic diseases. In the past decade, growing evidence has demonstrated that the eye's structure and function mirror multiple systemic health conditions, especially in cardiovascular diseases, neurodegenerative disorders, and kidney impairments. This has given rise to the field of oculomics-the application of ophthalmic biomarkers to understand mechanisms, detect and predict disease.

Finite Element Analysis of Mechanical Ocular Sequelae from Badminton Shuttlecock Projectile Impact.

Purpose: With the growing popularity of badminton worldwide, the incidence of badminton-related ocular injuries is expected to rise. The high velocity of shuttlecocks renders ocular traumas particularly devastating, especially with the possibility of permanent vision loss. This study investigated the mechanism behind ocular complications through simulation analyses of mechanical stresses and pressures upon shuttlecock impact.

Optic disc edema during strict 6° head-down tilt bed rest is related to one-carbon metabolism pathway genetics and optic cup volume.

Some astronauts on International Space Station missions experience neuroophthalmological pathologies as part of spaceflight associated neuro-ocular syndrome (SANS). Strict head-down tilt bed rest (HDTBR) is a spaceflight analog that replicates SANS findings and those who had 3-4 risk alleles (G and C alleles from the methionine synthase reductase [MTRR] A66G and serine hydroxymethyltransferase [SHMT1] C1420T, respectively) as compared to 1-2 risk alleles, had a greater increase in total retinal thickness (TRT). The objective of this study was to identify factors that contribute to the individual variability of the development of SANS in a 60 d HDTBR at the German Aerospace Center's:envihab facility, Cologne Germany.

Oculomics analysis in multiple sclerosis: Current ophthalmic clinical and imaging biomarkers.

Multiple Sclerosis (MS) is a chronic autoimmune demyelinating disease of the central nervous system (CNS) characterized by inflammation, demyelination, and axonal damage. Early recognition and treatment are important for preventing or minimizing the long-term effects of the disease. Current gold standard modalities of diagnosis (e.

"Spaceflight-to-Eye Clinic": Terrestrial advances in ophthalmic healthcare delivery from space-based innovations.

The phrase "Bench-to-Bedside" is a well-known phrase in medicine, highlighting scientific discoveries that directly translate to impacting patient care. Key examples of translational research include identification of key molecular targets in diseases and development of diagnostic laboratory tests for earlier disease detection. Bridging these scientific advances to the bedside/clinic has played a meaningful impact in numerous patient lives.

Retina Oculomics in Neurodegenerative Disease.

Ophthalmic biomarkers have long played a critical role in diagnosing and managing ocular diseases. Oculomics has emerged as a field that utilizes ocular imaging biomarkers to provide insights into systemic diseases. Advances in diagnostic and imaging technologies including electroretinography, optical coherence tomography (OCT), confocal scanning laser ophthalmoscopy, fluorescence lifetime imaging ophthalmoscopy, and OCT angiography have revolutionized the ability to understand systemic diseases and even detect them earlier than clinical manifestations for earlier intervention.