Robert Ritch, MD
Shelley and Steven Einhorn Distinguished Chair
Professor of Ophthalmology
Surgeon Director Emeritus and Chief, Glaucoma Service
New York Eye and Ear Infirmary of Mount Sinai
If there were something simple you could do to save your sight, wouldn't you do it?
According to the National Eye Institute, nearly three million Americans have glaucoma -- a leading cause of blindness in the United States -- yet half of them don't know they have it. Glaucoma damages the optic nerve, which carries visual information from the eye to the brain. In most cases, the disease produces no early symptoms and, unchecked, worsens over time.
As someone who has devoted his career to the study and treatment of glaucoma, I know only too well that if not detected and controlled early, it can result in irreversible vision loss or blindness. And the only way to discover glaucoma early is to get periodic, comprehensive eye examinations.
Knowing whether you have glaucoma is important not only so you can slow or stop its progression with treatment (eyedrops, pills, and/or surgery), but also so you can limit activities that may make it worse.
What Is Glaucoma?
Glaucoma is not a single disease, but rather the end result of a variety of diseases that affect the eye. Elevated pressure inside the eye (called intraocular pressure, or IOP) is the most important known risk factor for glaucoma, but is not the disease itself. You can also get glaucoma at what are regarded as normal pressures.
Do You Have Glaucoma?
Regular, comprehensive eye examinations from an optometrist, ophthalmologist, or glaucoma specialist are necessary for early detection of glaucoma, when there's still time to prevent vision loss. Just checking the pressure inside your eye is not enough; a full exam should also include testing your visual field and inspecting your optic nerve.
The American Academy of Ophthalmology generally recommends having a comprehensive eye examination by age 40, and thereafter as follows: age 40 to 54, every two to four years; age 55 to 64, every one to three years; and age 65 or older, every one to two years. Ask an eye doctor about your risk for developing glaucoma, as people at increased risk, such as those with diabetes, a family history of glaucoma, or who are of African descent, should be examined earlier and more frequently.
Activities That May Worsen Glaucoma
If you have glaucoma, it is important to be aware of and limit activities that increase IOP or decrease blood flow to the eye (a risk factor for normal-pressure glaucoma), as these potentially could further damage your optic nerve and eyesight. Such activities include:
• Practicing certain yoga positions. Previous research has shown that IOP rises markedly while people are in the headstand position. In a new study at New York Eye and Ear Infirmary of Mount Sinai, we looked at four other common head-down yoga positions: downward-facing dog, standing forward bend, plow, and legs up the wall. We found that during these inverted positions, which were held for two minutes, participants experienced a sudden and significant rise in IOP, with the greatest increase occurring during downward dog.
More research is needed to say definitively whether head-down yoga positions affect the progression of glaucoma. But in the meantime, due to the risk of increasing IOP and damaging the optic nerve, glaucoma patients should avoid these positions and ask their yoga instructors for appropriate modifications. (If you have regular, complete eye examinations and do not have glaucoma, you needn't avoid these inverted positions.)
• Undergoing lengthy surgery in an inverted position. Medical literature has shown that spinal surgery can cause high IOP and visual-field damage when patients are positioned with their head lower than their heart for several hours. A recent study found similarly elevated IOP in patients undergoing robotic-assisted prostate surgery in the same position. If you have glaucoma and need spinal or prostate surgery, talk to your surgeon, who should be aware that head-down positions may be especially risky for you.
• Attempting to exhale against closed airways. Glaucoma patients should avoid holding their breath while exerting themselves (called the Valsalva maneuver), such as during pushups, heavy weight lifting, or straining on the toilet.
• Taking blood pressure medication at night. Researchers have found that low nighttime blood pressure (i.e., during sleep) may lead to worsening vision problems for people with glaucoma. Everybody's blood pressure dips during sleep, but taking blood pressure medication before bedtime may cause glaucoma patients' to over-dip, and should be avoided. If you have glaucoma and take medication for high blood pressure, talk with your internist or cardiologist about when to take each dose.
• Letting sleep apnea go untreated. Obstructive sleep apnea (OSA), a condition in which breathing stops periodically during sleep due to blocked airways, is a risk factor for normal-tension glaucoma. Eighty percent of OSA goes undiagnosed, yet it can be treated effectively with a continuous positive airway pressure (CPAP) machine. If you have glaucoma and snore loudly (a possible indication of sleep apnea), it's a good idea to be evaluated for OSA, as treating it may slow the progression of glaucoma.
• Sleeping on one side. If you have glaucoma, avoid habitually sleeping on one side with your eye pressed into a pillow or resting against your hand. If that's impossible, wear an eye shield to protect the eye, or try sleeping face up on a wedge pillow to keep from turning sideways.
Remember, glaucoma is a progressive disease. Early detection and treatment are the only way to prevent glaucoma-related vision impairment and blindness, so make an appointment with your eye doctor today!