Eye
For ophthalmology, the human evidence is very limited: only a few small human studies exist — including one randomized crossover investigation and measurement studies, for example on intraocular pressure — while the bulk of the work consists of preclinical research in animal and cell models.
The studies examined hydrogen-rich water, hydrogen-rich saline and H₂ inhalation, predominantly in connection with oxidative stress at the ocular surface and the retina. Endpoints included intraocular pressure as well as oxidative and functional markers.
From this narrow data base, no robust statements about a therapeutic benefit in eye diseases can be derived. The results are preliminary and hypothesis-generating; H₂ is no substitute for ophthalmological treatment.
Human studies on molecular hydrogen for Eye. This page collects the 17 studies catalogued in this area — 1 randomized trials, 1 pilot/observational studies and 10 reviews. Listed newest first.
2026 · Paparella — Medical Gases as Emerging Regulators of Paediatric Endocrine and Neurodevelopmental Pathways: A Mini-Review
Gaseous signalling molecules — including molecular hydrogen (H₂), nitric oxide, carbon monoxide and hydrogen sulphide — are increasingly recognised as modulators of the developing brain and endocrine system in children.
2024 · Takefuji — Hydrogen Inhalation Therapy for Inflammation and Eye Diseases: A Review of the Literature
This literature review in the journal Eye surveys published evidence on hydrogen inhalation therapy for inflammatory conditions — with a focus on eye diseases.
2021 · Bragina — Intestinal microbiota of athletes.
This systematic review of 14 studies finds that athletes harbour a more diverse gut microbiome than sedentary individuals, with higher proportions of bacteria that ferment complex carbohydrates into short-chain fatty acids — including species that use hydrogen gas (H₂) and formate to drive fermentation.
2019 · Cejka et al. — The preventive and therapeutic effects of molecular hydrogen in ocular diseases and injuries where oxidative stress is involved.
Molecular hydrogen (H₂) is uniquely suited for eye diseases because it is the only antioxidant that crosses both the blood-brain and blood-ocular barriers.
2018 · Chen — Research progress of hydrogen-rich saline for eye diseases.
This Chinese-language review summarizes the published research on hydrogen-rich saline (and hydrogen-rich water) for the treatment of eye diseases, including glaucoma, retinal ischemia, and other ocular conditions.
2015 · Ohta — Molecular hydrogen as a novel antioxidant: overview of the advantages of hydrogen for medical applications.
Molecular hydrogen (H₂) is a mild, selective antioxidant that neutralizes the most damaging reactive oxygen species without disrupting normal cellular redox signaling — a key advantage over broad-spectrum antioxidants.
2014 · Ohta — Molecular hydrogen as a preventive and therapeutic medical gas: initiation, development and potential of hydrogen medicine.
One of the founding papers of hydrogen medicine, authored by Shigeo Ohta, summarises how H₂ was discovered to react with harmful hydroxyl radicals in cells — and why this makes it a candidate for preventing and treating a wide range of diseases.
2012 · Ohta — Molecular hydrogen is a novel antioxidant to efficiently reduce oxidative stress with potential for the improvement of mitochondrial diseases.
This review by Shigeo Ohta — one of the founders of modern H₂ medicine — surveys the biological effects of molecular hydrogen across more than 38 diseases, physiological states, and clinical tests documented in the years following the 2007 Nature Medicine paper.
2011 · Ohta — Recent progress toward hydrogen medicine: potential of molecular hydrogen for preventive and therapeutic applications.
Since the landmark 2007 Nature Medicine paper demonstrating that molecular hydrogen (H₂) selectively neutralizes toxic hydroxyl radicals, the field of hydrogen medicine has grown rapidly.
2011 · Noda et al. — The principle and the potential approach to ROS-dependent cytotoxicity by non-pharmaceutical therapies: optimal use of medical gases with antioxidant properties.
Oxidative stress and reactive oxygen species (ROS) are implicated in many major diseases including inflammation, diabetes, glaucoma, cancer, ischemia, and neurodegeneration.
2023 · Najmanová — Effect of Acute Hydrogen-Rich Water Intake on Intraocular Pressure in Healthy Subjects
Rapidly drinking 1260 ml of fluid raises intraocular pressure — and with hydrogen-rich water (HRW) it does so clinically relevantly more often than with placebo.
2026 · Zhu — Self-Adaptive Hydrogen Nano-Delivery System in Glaucoma Management: Synergistic Antioxidation and Anti-inflammation Therapeutic Strategy
Glaucoma-induced optic nerve damage remains a leading cause of blindness, and current treatments focus only on lowering intraocular pressure — ignoring the oxidative stress and inflammation that drive the underlying damage.
2025 · Wang — Effect of hydrogen-rich saline on melanopsin after acute blue light-induced retinal damage in rats
Hydrogen protects the retina from blue light: In rats with blue-light-induced retinal damage, hydrogen-rich saline (HRS) accelerated recovery — with markedly more melanopsin and more functional light-sensitive ganglion cells within two weeks.
2016 · Qin — Hydrogen-Rich Saline as an Innovative Therapy for Cataract: A Hypothesis
This paper proposes a theoretical rationale for using molecular hydrogen as an antioxidant to protect against cataract formation — based on H₂'s known ability to selectively neutralise damaging reactive oxygen species (ROS).
2016 · Wolf — H₂ metabolism is widespread and diverse among human colonic microbes
A large-scale genomic and metagenomic analysis shows that 70% of microbial species in the human colon encode genes for metabolising molecular hydrogen (H₂), and that electron-bifurcating fermentation — rather than respiratory H₂ oxidation — is the dominant mechanism of H₂ recycling in the gut.
2010 · Sugiyama — Use of laser speckle flowgraphy in ocular blood flow research.
This technical review describes laser speckle flowgraphy (LSFG), a non-contact imaging technique for measuring blood flow in the optic nerve head, choroid, retina and iris.