Navigation Links
High-altitude climbs may cause corneal swelling, but do not appear to affect vision

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.
JAMA and Archives Journals

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:
(Date:11/24/2015)... , ... November 24, 2015 , ... Dr. Todd S. ... offer laser services to many of his patients. Dr. Afferica now uses the BIOLASE ... reduce the amount of time the doctor uses other traditional cutting tools, such as ...
(Date:11/24/2015)... ... November 24, 2015 , ... Young patients with a wide variety of dental ... Dr. Kedar S. Lele, who are pediatric dentists in Tucson, AZ . Unlike ... iPlus 2.0™ system causes minimal discomfort and bleeding to the patient during treatment and ...
(Date:11/24/2015)... ... November 24, 2015 , ... ... Black Friday sale a week early, offering 40% off select bras and underwear ... apparel industry through both mobile fit technology and the latest fashion, quickly becoming ...
(Date:11/24/2015)... ... November 25, 2015 , ... Catalent Pharma Solutions, the leading ... health and global clinical supply services, today announced that Dr. Christine Milligan, Global ... Asia Conference, to be held at the InterContinental Seoul COEX Hotel, Seoul, Republic ...
(Date:11/24/2015)... ... 2015 , ... The hospitals and health systems on this ... care. They have received recognition for excellence from various reputable organizations in areas ... Hospital Review selected hospitals for inclusion based on national rankings and awards from ...
Breaking Medicine News(10 mins):
(Date:11/24/2015)... -- iRhythm Technologies, Inc. , a leading digital health care ... will participate in the 27th Annual Piper Jaffray Healthcare Conference at ... . Kevin King , Chief Executive Officer of ... 8:50am ET. --> --> ... . --> iRhythm is a privately held ...
(Date:11/24/2015)... Mass. , Nov. 24, 2015  Boston Scientific ... in the Oppenheimer 26th Annual Healthcare Conference on December ... Susie Lisa , vice president, Investor Relations, ... host analyst beginning at approximately 8:35 a.m. ET. ... will participate in a 30-minute question-and-answer session with the ...
(Date:11/24/2015)... , Nov. 24, 2015  BioPlast Manufacturing, ... the medical research, clinical diagnostic and biotech environments, ... leading manufacturer of quality petri dishes. This acquisition ... clients a platform of products that are designed ... with the highest quality.  ...
Breaking Medicine Technology: