# The preventive and therapeutic effects of molecular hydrogen in ocular diseases and injuries where oxidative stress is involved.
> 酸化ストレスが関与する眼疾患・眼損傷における分子状水素の予防的・治療的効果に関するレビュー


## Abstract

Oxidative stress, driven by excess reactive oxygen species (ROS) or diminished endogenous antioxidant capacity, underlies the onset and progression of numerous ocular conditions. Molecular hydrogen (H2) possesses several properties that make it particularly relevant in this context: it is the only known antioxidant capable of crossing both the blood-brain and blood-ocular barriers, it diffuses rapidly through tissues owing to its small molecular size, and it selectively neutralizes hydroxyl radicals and peroxynitrite. Beyond direct ROS scavenging, H2 also exhibits anti-inflammatory, anti-apoptotic, cytoprotective, and mitohormetic activities, with no observed toxicity even at elevated concentrations. This review consolidates findings from animal models and human clinical investigations, indicating that H2-mediated suppression of oxidative stress can prevent or ameliorate various ocular diseases, and may slow progression in severe degenerative conditions.

### Mechanism

H2 crosses the blood-ocular barrier, selectively scavenges hydroxyl radicals and peroxynitrite, and exerts anti-inflammatory, anti-apoptotic, and mitohormetic effects, collectively protecting ocular tissues from oxidative damage.

## Bibliographic

- **Authors**: Cejka C, Kubinova S, Cejkova J
- **Journal**: Free Radic Res
- **Year**: 2019
- **PMID**: [30773939](https://pubmed.ncbi.nlm.nih.gov/30773939/)
- **DOI**: [10.1080/10715762.2019.1582770](https://doi.org/10.1080/10715762.2019.1582770)
- **Study type**: review
- **Delivery route**: mixed routes
- **Effect reported**: not assessed

## Delivery context

This study combines multiple delivery routes. As a general principle, the most efficient route for routine hydrogen intake is inhalation. Inhalation carries explosion risk (empirical LFL of 10%; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

## Safety notes

This study combines multiple delivery routes. As a general principle, the most efficient route for routine hydrogen intake is inhalation. Inhalation carries explosion risk (empirical LFL of 10%; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 30773939. https://h2-papers.org/en/papers/30773939
> **Source**: PubMed PMID [30773939](https://pubmed.ncbi.nlm.nih.gov/30773939/)