Inhaled Hydrogen Gas Protects Vision in Eye Injury Study
- Authors
- Ruobing Wang, Jiangchun Wu, Zeli Chen, Fangzhou Xia, Qinglei Sun, Lin Liu
- Journal
- Brain Research
- Year
- 2016
- DOI
- 10.1016/j.brainres.2015.12.015
- Study Type
- Rat
- Outcome
- Positive
- Peer Reviewed
- Yes
- Country
- China
- Health Condition
- Retinal Ischemia/Reperfusion Injury
- Body System
- Visual System
TL;DR
Breathing in hydrogen-rich air can protect the nerves in the eye and improve vision after an eye injury caused by poor blood flow.
Key Finding
Inhaled hydrogen gas significantly increased the survival of retinal nerve cells and improved visual function in rats with retinal ischemia/reperfusion injury, while reducing markers of oxidative stress and inflammation.
Summary
This study tested whether inhaling hydrogen gas could protect nerve cells in the retina (the light-sensitive tissue at the back of the eye) from damage caused by interrupted blood flow and then restored blood flow. Researchers induced this type of injury in rats' eyes, then had the rats inhale a mixture of 67% hydrogen and 33% oxygen for one hour daily for a week. They found that rats receiving hydrogen inhalation had more surviving retinal nerve cells, better vision function, and lower levels of harmful inflammatory molecules compared to untreated rats.
Practical Takeaway
This rat study provides early evidence that hydrogen gas inhalation may protect retinal nerve cells from ischemic injury through anti-inflammatory and antioxidant mechanisms. However, this is animal research only, and human studies would be needed to determine whether these findings apply to people with eye diseases. The practical feasibility and safety of high-dose hydrogen inhalation in humans remains unknown.
Abstract
Retinal ischemia/reperfusion (I/R) injury plays a crucial role in the pathophysiology of various ocular diseases. Intraperitoneal injection or ocular instillation with hydrogen (H2)-rich saline was recently shown to be neuroprotective in the retina due to its anti-oxidative and anti-inflammatory effects. Our study aims to explore whether postconditioning with inhaled H2 can protect retinal ganglion cells (RGCs) in a rat model of retinal I/R injury. Retinal I/R injury was performed on the right eyes of rats and was followed by inhalation of 67% H2 mixed with 33% oxygen immediately after ischemia for 1h daily for one week. RGC density was counted using haematoxylin and eosin (HE) staining and retrograde labeling with cholera toxin beta (CTB). Visual function was assessed using flash visual evoked potentials (FVEP) and pupillary light reflex (PLR). Potential biomarkers of retinal oxidative stress and inflammatory responses were measured, including the expression of 4-Hydroxynonenalv (4-HNE), interleukin-1 beta (IL1-β) and tumor necrosis factor alpha (TNF-α). HE and CTB tracing showed that the survival rate of RGCs in the H2-treated group was significantly higher than the rate in the I/R group. Rats with H2 inhalation showed better visual function in assessments of FVEP and PLR. Moreover, H2 treatment significantly decreased the number of 4-HNE-stained cells in the ganglion cell layer and inhibited the retinal overexpression of IL1-β and TNF-α that was induced by retinal I/R injury. Our results demonstrate that postconditioning with inhaled high-dose H2 appears to confer neuroprotection against retinal I/R injury via anti-oxidative, anti-inflammatory and anti-apoptosis pathways.