Over three million Americans have glaucoma; only half know about it, according to the Glaucoma Research Foundation. There may be no symptoms in the early stages, so many people don't find out they have it until significant damage has been done to the retina. Since aerobic exercise is increasing in popularity, a research team in Greece decided to investigate whether there should be any restrictions on exercise for glaucoma patients with increased intraocular pressure.
The researchers studied 145 subjects divided into seven groups, as follows:
1. Normal eye pressure, no eye drops
2. Normal eye pressure, timolol maleate (beta blocker) drops in one eye
3. Normal eye pressure, latanoprost (prostaglandin analog) drops in one eye
4. Normal eye pressure, brimonidine tartrate (alpha agonist) drops in one eye
5. Glaucoma, timolol maleate drops in both eyes
6. Glaucoma, latanoprost drops in both eyes
7. Glaucoma, combination anti-glaucoma drops in both eyes
The exercise routine was 10 minutes of bicycle ergometer at 60 to 80 watts, with a target heart rate of 110 per minute.
The results were pleasantly surprising: intraocular pressure decreased significantly for all seven groups when measured before and after exercise. The authors note, “It is obvious that these patients should be encouraged to perform aerobic exercise.”
All glaucoma patients in this study had primary open angle glaucoma, which is the most common variety. Other types include pigmentary, congenital and juvenile glaucoma. Since these conditions were not studied, the authors advise caution for such patients in their exercise programs.
The Glaucoma Research Foundation also cautions that normal pressure is not a guarantee against glaucoma. Normal Tension Glaucoma can be diagnosed by examination of the optic nerve in a standard eye exam. For any type, early detection and treatment can usually preserve vision. Good nutrition and exercise are part of the therapy recommended by this organization.
The one caution in exercise is that physical activities with inverted positions, that is, head down, may not be safe. Headstands and some yoga positions qualify.
Currently there are 537 glaucoma clinical trials listed on the web page for US research studies. Some of these are recruiting healthy volunteers who are at risk for glaucoma. Risk factors include age (over 60 years old), family history, diabetes, high blood pressure, corneal thickness less than 0.5 mm, high degree of nearsightedness, eye injury and high use of steroids to treat asthma.
Resources:
-Natsis K et al, “Aerobic exercise and intraocular pressure in normotensive and glaucoma patients”, BMC Ophthalmology 2009 Aug; 9:6.
-Glaucoma Research Foundation
http://www.glaucoma.org/
-Clinical Trials
http://clinicaltrials.gov/ct2/results?term=glaucoma
Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.