Healthy Lifestyles
Chat Highlights
December 10, 2003

Norma Devine, Editor

On Wednesday, December 10, 2003, Dr. Elliot Werner, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Healthy Lifestyle."

Moderator:  Tonight's topic is healthy lifestyles. 

Dr. Elliot Werner:  I wish I knew more about healthy lifestyles. I could use them myself.

Moderator:  With the new year fast approaching and resolutions to be made, this seems like a good time for us glaucoma patients to think about beneficial changes in lifestyle.  For instance, would a low-fat or no-carbohydrate diet have a beneficial effect on our eyes? 

Dr. Elliot Werner:  One of the problems with discussing lifestyle and issues like diet and eye disease is that there is precious little evidence for any direct effect of any of this on the eyes.   We only have evidence of indirect effects, such as through diabetes or high blood pressure.  I don't know of any studies or information relating low-carbohydrate or low-fat diets to eye health.

P:  Are there any foods in particular that are good for our eyes? 

Dr. Elliot Werner:  I would say that proper diet and nutrition, exercise, adequate sleep, avoidance of stress, no smoking, and moderate alcohol use are good for health in general and probably spill over into the eyes.  To answer more specifically, certain vitamins are needed for proper eye function.  A good balanced diet will usually provide them.

P:  Are any particular vitamins good for the eyes?  

Dr. Elliot Werner:  That depends on what you mean by good for the eyes. The retina needs vitamin A to function.  Most people in the USA get adequate vitamin A.  B vitamins are needed for proper function of the optic nerve.  There is some evidence that lutein and zinc will slow the development of macular degeneration.  There is no evidence that vitamins will prevent or treat the common eye diseases, such as glaucoma, cataracts, and macular degeneration.

P:  Is there no evidence that vitamins will prevent or treat the common eye diseases because the studies haven't been done, or because the study results are negative?  

Dr. Elliot Werner:  Mostly because the studies haven't been done in a way needed to answer the question.

P:  The lack of empirical evidence that you cite for the benefits of vitamins in the living human eye is very frustrating for those of us who want to assume some sense of control over our glaucoma.  So for those who choose to take vitamins, if only for their theoretical benefit, are there any with which we should be especially careful -- that can cause damage (e.g., liver, etc.) in higher dosages, either alone or in combination?  I'm also talking about supplements and hormones, such as Quercetin, L-Glutathione, melatonin, etc.

Dr. Elliot Werner:  The problem is that doing the studies necessary to answer the question would require many years and a large number of subjects and cost a great deal of money.  So it is a question of priorities. It is probably more important to spend those research dollars on other things like AIDS, cancer, multiple sclerosis, etc., than on vitamins and the eye.  Most any substance in large enough quantities can be harmful, especially fat-soluble vitamins such a A, D, E, and K.  Check the FDA recommended daily requirements and try not to exceed them.

P:  Could a high-protein diet cause problems for a patient with uveitic glaucoma?  Specifically, could there be an increase in undigested proteins leaking through the blood vessels into the eye, causing blockage?

Dr. Elliot Werner:  There is no evidence for that. Not many studies have been done to answer that question, and protein consumption in diet does not show up as a factor in studies on uveitis.

P:  I use Ocuvite PreserVision, as recommended by my retina specialist. I also have ARMD (age-related macular degeneration).  I believe the vitamins are helping.

Dr. Elliot Werner:  You are probably right.  There is pretty good evidence that some of the supplements in Ocuvite retard the development of macular degeneration.

P:  I have read that insufficient thiamin can result in damage to the optic nerve.  Would that kind of damage be glaucoma?  Also, I have read that persons with glaucoma have low levels of thiamin in their blood.  Can you comment on this, please?

Dr. Elliot Werner:  Thiamin deficiency can cause a type of optic neuritis that doesn't really resemble glaucoma.

P:  I have read that a study of 400 eye patients showed a strong association of pigmentary-dispersion and pseudoexfoliative glaucoma with excessive protein intake (greater than 3x the USDRA). Can you comment on this, please?

Dr. Elliot Werner:  I'm not aware of the study. Do you know where it was published?

P:  It appeared in J Am Coll Nutr (American Journal of Clinical Nutrition)10( 5): 536, 1991.  

Dr. Elliot Werner:  Thanks, I'll look it up in the library and send my comments to the webmaster to forward to you.

P:  Have your ever heard of magnets used to help reduce the IOP?

Dr. Elliot Werner:  Again, there is no evidence for that, but studies have not been done.  We know that MRI (magnetic resonance imaging), which uses a very strong magnetic force has no effect on IOP.

P:  What kind of long-term effects are there from dilating drops, other than cataracts?

Dr. Elliot Werner:  Most dilating drops will raise the IOP so they can aggravate glaucoma.  People frequently develop allergies to them. They can have systemic effects and cause cramps and constipation as well as dry eyes. By dilating the pupil they let more light in the eye and can result in greater sensitivity and toxicity from sunlight.  But if you need them, you need them.

P:  Is green tea good for the body and the eyes?  

Dr. Elliot Werner:  I don't know much about green tea.  What is in it?

Moderator:  I believe green tea has \anti-oxidant properties.

Dr. Elliot Werner:  Antioxidants, such as vitamin C and E, can reduce the risk of cataracts and macular degeneration.

P:  Does caffeine have any effect on IOP?

Dr. Elliot Werner:  Caffeine does not seem to have an effect on IOP. Ingesting a large amount of any fluid in a short time will increase IOP, so it is the water in the eight cups of coffee that is the problem, not the caffeine.

P:  What about alcohol consumption?  Any thoughts about a little bit, like a glass of wine with dinner nightly?  Any thoughts on someone who drinks too much, like a six-pack a night or binges?  Can that affect blood flow to the eye and damage the optic nerve?

Dr. Elliot Werner:  Moderate alcohol use does not seem to be harmful. In fact, it has been shown that moderate alcohol use decreases the risk of heart attacks and can lower IOP.  Excessive drinking (more than one shot, two glasses of wine or two beers per day) can cause the IOP to go up and can damage the optic nerve. 

P:  I'm guessing that high cholesterol and smoking would affect intraocular pressure (IOP).

Dr. Elliot Werner:  There's no evidence of that. We do know that regular aerobic exercise can lower IOP.

P:  What kind of exercise routine would you suggest to help improve the health of our eyes?

Dr. Elliot Werner:  Any regular aerobic exercise, such as jogging, cycling, swimming -- even vigorous walking -- at least one-half hour a day, at least four days a week.  If you have not been exercising regularly, check with your doctor first to be sure your heart and lungs are in shape to do exercise.

P:  Does "regular" aerobic exercise mean every day, or would every couple of days be just as good.

Dr. Elliot Werner:  The usual recommendation is at least four days a week.

P:  Why should glaucoma patients avoid exercise that involve keeping the head lower than the rest of the body?  

Dr. Elliot Werner:  Because that raises the blood pressure in the veins of the head and eyes and causes the IOP to go up.  Glaucoma patients should avoid any exercise involving a lot of the head-down position.

P:  I've been told it is important to exercise the muscles in our eyes by reading, computing, etc.  Does eye strain cause any damage?

Dr. Elliot Werner:  That is an interesting question. In general, you cannot damage your eyes by using them to look at things, other than excessively bright lights like the sun.  Any repetitive activity can cause fatigue, and so-called eye strain can produce discomfort.  But there is no evidence that using a computer or reading causes any damage to the eyes.  It's almost impossible for us not to use our eyes.  We use them all the time we are awake, so the concept of eye exercise is a fallacy, in my opinion.

P:  After my trabeculectomy, I had hypotony for an extended time.  I had to be mindful of straining and lifting.  Now that I no longer have hypotony, would there be any restrictions on exercise such as weight training?

Dr. Elliot Werner:  Probably not as long as there is not too much straining.  Remember that lifting heavy weights causes your IOP to go up.

P:  In a previous chat, one of your colleagues mentioned weight loss as beneficial for glaucoma patients.  I presume he meant maintaining a normal weight.  Can you tell us what the weight factor might be?

Dr. Elliot Werner:  Obesity is associated with a number of health problems, such as diabetes and hypertension.  Studies on glaucoma have not shown obesity to be a specific risk factor for glaucoma.  I don't know of any evidence that weight loss has an effect on glaucoma, again because the studies have not been done.

P:  I've heard that over-exposure to sunlight can be harmful, and we should protect our eyes as well as our skin.  

Dr. Elliot Werner:  Yes.  Exposure to sunlight seems to be a risk factor for developing cataracts, as well as macular degeneration.  Excessive exposure to sunlight generally is not good.  In addition to the effects on the eyes, it causes premature aging of the skin and skin cancer.

P:  This may seem silly, but can the slit lamp lights, or the magnifying lens and light used to see into the back of the eye do damage to the eye if shone into the eye for excessively long periods?  I've had medical students do that. Being a veteran eye patient, I can tolerate it for a while, but I'm concerned about it doing damage, as it takes many minutes for my eyes to get vision back after prolonged examinations.  

Dr. Elliot Werner:  There is such a thing as light toxicity.  Instrument lights on the retina for a long time can produce damage.  It is unusual in awake patients, because the eye is constantly moving, so the light doesn't fall on the same part of the retina all the time.  But you should limit the students to a minute or so.

P:  How do you advise your patients with pigmentary glaucoma (or pigment dispersion syndrome) about exercise?  Do you consider it a prudent trade-off to give up the general cardiovascular benefits of regular strenuous exercise for the protection from episodic spikes in IOP resulting from pigment release?  I've asked this of other clinicians, and never felt that they had a real handle on what the risks and benefits of such a trade-off are.

Dr. Elliot Werner:  The only exercise that seems to cause problems is vigorous exercise involving a lot of rapid head movements, such as basketball or gymnastics. I have rarely seen pigmentary glaucoma patients develop problems from other types of exercise, such as jogging, swimming, cycling, or even tennis.  

P:  It was my understanding that "impact" sports and exercise are detrimental to pigmentary glaucoma because they cause excessive pigmentary dispersion. Is that correct?  

Dr. Elliot Werner:  You are correct.  They cause sudden release of large amounts of pigment, which can cause the IOP to go up quite high acutely.

P:  I was previously misdiagnosed as having pigmentary glaucoma. Now it has been determined that I have open-angle glaucoma. I live in northern Canada, burn wood for heat, and do a fair bit of heavy wood chopping.  That would have been out of the question if I had pigmentary glaucoma, but is that activity okay for me now?

Dr. Elliot Werner:  It's hard to make a blanket rule because every patient is so different.  The best way to find out would be to see if your doctor would agree to see you and measure your IOP immediately after chopping wood, if that is possible.  If nothing happens, you have no problem.

P:  When I had serial tonometry, there appeared to be spikes coinciding with jogging but not with walking.  But even serial tonometry is such a snapshot of actual IOP over real time that I wonder how meaningful it is.

Dr. Elliot Werner:  It's hard to know.  If you're getting spikes of IOP with jogging, you may be unusually sensitive to the effects of exercise.  It's a dilemma.  If exercise is an important part of your life and your glaucoma cannot be adequately controlled given your exercise regime, you may consider filtering surgery for better IOP control ,but that carries some risk with it.

P:  If placing the head below the heart produces an increase in intraocular pressure, and if IOP can dip during sleep, should we sleep with the head well elevated above the heart?

Dr. Elliot Werner:  Probably not, because most people have a decrease in blood pressure during sleep.  Sleeping upright can result in temporary loss of circulation to the brain and can cause strokes.  Better to sleep lying down.  By the way, when I visited Monticello, the guide told us that Thomas Jefferson always slept sitting up. He believed it was harmful to sleep lying down.

P:  Some of us here have had filtering surgery (trabeculectomies) and are under the impression that we can pretty much live our lives with no restrictions on activity.  Would you agree?

Dr. Elliot Werner:  I would agree, unless you have some very unusual complication.  Once you have recovered from filtering surgery, there is no need to limit activity.  You should wear goggles while swimming, and scuba diving can be a problem.  Other than that, enjoy life.

P:  One day will it be possible to edit our DNA and rid our bodies of any disease?

Dr. Elliot Werner:  I'm not sure we'd want to.  Remember the law of unintended consequences.  I know it is very frustrating to talk about lifestyles and eye disease, because we all want to feel we can control our destiny.  There are many eye diseases that have significant environmental factors, and certainly creating the ideal environment with diet, nutrition, exercise, smoking, etc., can help us live longer and be healthier.  However, when it comes to most eye problems faced by 21st century Americans, probably the single most important factor, in my opinion, is genetics, and we can't change our DNA.  That is what is so frustrating.

Moderator:  Thank you, Dr. Werner, for your time and candid answers.

Dr. Elliot Werner:  You're welcome.  Happy holidays and happy new year.  See you next time.

End of highlights for December 10, 2003.

On December 17, Dr. Spaeth discussed "Genetics and Glaucoma" in the Chat room. Click here for highlights of that meeting.

Click here for the most recent glaucoma chat highlights and links to the chat archives.

Click here for upcoming glaucoma chat events.