Navigation Links
High-altitude climbs may cause corneal swelling, but do not appear to affect vision
Date:2/8/2010

Swelling commonly occurs in the corneas of mountain climbers, but does not appear to affect vision at altitudes of up to 6,300 meters (about 20,670 feet), according to a report in the February issue of Archives of Ophthalmology, one of the JAMA/Archives journals.

"High-altitude mountaineering is a popular recreational sport among healthy lowlanders," the authors write as background information in the article. "As a consequence of the exposure to hypobaric atmospheric conditions with a consecutive decrease in oxygen saturation, high-altitude climbing may lead to acute mountain sickness and the rare but potentially fatal high-altitude cerebral edema." Changes to the cornea, the transparent membrane covering the front of the eye, also occur during high-altitude climbs and may cause potentially hazardous vision loss.

Martina Monika Bosch, M.D., of University Hospital Zurich, Switzerland, and colleagues studied the effects of high-altitude climbing on corneal thickness among 28 healthy volunteers climbing Mount Muztagh Ata in western China. The mountaineers were randomly assigned to two different ascending paths, with one group being allotted a shorter time to acclimate before ascending to 6,265 meters. Corneal thickness, visual acuity and blood oxygen levels were measured in climbers before, during and after their ascent, and symptoms of acute mountain sickness were also assessed.

In groups with both patterns of ascent, corneal thickness increased with increasing altitude and decreased after descent, and the amount of decrease in blood oxygen levels paralleled this increase. The group with the shorter acclimatization time experienced a greater increase in corneal thickness. However, no significant decrease in visual acuity was observed in either group.

When controlling for age and oxygen saturation, there was a correlation between symptoms of mountain sickness and corneal thickness. This was possibly due to these individuals' higher overall susceptibility to inadequate oxygen supplies.

The exact cause of corneal swelling during ascent remains controversial, the authors note. The current findings suggest that the body's delivery of oxygen to the aqueous humorthe fluid inside the eyeball, between the cornea and irismay be more important in corneal oxygen levels than previously thought.

"It seems that visual acuity in healthy corneas is not adversely affected despite the presence of edema at altitudes up to 6,300 meters," the authors conclude. However, it is likely that ascents to more extreme altitudesabove 8,000 meters or about 26,000 feetmay induce greater damage to the cornea and lead to dangerous visual loss.


'/>"/>

Contact: Martina Monika Bosch, M.D.
martina.boesch@usz.ch
JAMA and Archives Journals
Source:Eurekalert

Related medicine news :

1. VivoMetrics LifeShirt Going to South Pole to Uncover Clues to High-Altitude Illness
2. Amilpar - Revenues Increase by 26.5% and Adjusted Net Income Climbs 28.7% in 2008
3. James Chippendale Climbs the Mountain of Life
4. Doctors miss major cause of infertility and obesity
5. Herbal Remedies Can Cause Cardiac Problems
6. No Surprise to David Perecman And Other Personal Injury Attorneys, Vehicles Lead All Causes of Injury at New York Hospital
7. Mental illnesses are second leading cause of time off work in Spain
8. Tobacco Toxin Helps a Protein Cause Lung Cancer
9. How sunlight causes skin cells to turn cancerous
10. Evolving Strains of HIV May Cause Wave of Drug Resistance
11. American Lung Association Report Card: Federal Government Makes Major Strides; Most States Flunk for Neglecting to Prevent Tobacco-Caused Disease
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/20/2017)... ... January 20, 2017 , ... “Mary Magdalene: Grace is Greater than Sin”: ... who witnessed Jesus Christ firsthand. “Mary Magdalene: Grace is Greater than Sin” is the ... an educator interacting with countless women who had little knowledge of the female characters ...
(Date:1/20/2017)... ... ... a fine examination of how God handles sin, including how to let go of lingering ... for over ten long years has been waiting to release this powerful insight about forgiveness ... been serving the Lord for over twenty years, and he has been preaching and teaching ...
(Date:1/20/2017)... ... ... beautiful and enchanting tale that teaches children the true meaning of Christmas. “Journey to Christmas” ... and a devoted woman of faith. , “Becoming a parent changes you. In my ... mind for years, but actually doing it might have been a while in coming if ...
(Date:1/20/2017)... ... , ... “God's Miracle Man: Against All Odds”: an inspiring affirmation of ... Keith C. A. Tucker, son of Minister Delores Pinnock and a Jamaican native who ... Hardy , “While sitting up in bed, I felt a pounding headache. It was ...
(Date:1/19/2017)... ... , ... Next week after January 20th, the fear for many is that ... health needs of over 30 million. Many interviews with Dr. Carol Francis at the ... servants were suppose to prioritize. Interviews provided below. , Among those present ...
Breaking Medicine News(10 mins):
(Date:1/19/2017)... , Jan. 19, 2017 The global ... billion by 2025, according to a new study ... anticipated to be predominantly driven by high R&D ... the large-scale production of new and therapeutically advanced ... of drugs at an unprecedented rate into the ...
(Date:1/19/2017)... YORK , Jan. 19, 2017 The ... provides understanding and access to partnering deals and agreements ... - Trends in partnering deals - Top deals by ... stage of development, technology type The report provides ... entered into by the world,s leading healthcare companies. ...
(Date:1/19/2017)... 2017 Conference Call and Webcast to Follow ... it will release results for the fourth quarter of 2016 on ... ... call at 4:30 PM ET on Wednesday, February 15, 2017, during ... financial results and other corporate activities. To participate in the conference ...
Breaking Medicine Technology: