Fort Collins Eye Doctors-Dr Kisling | Your Eye Health Is Our Number One Concern
Eye Doctors Report Macular Degeneration And Other Eye Disease Are Rapidly Increasing
Macular Degneration | National Eye Institute
According to the National Eye Insitute, a study that was conducted by the Eye Disease Prevalence Research Group found the graying of America is asssociated with vision loss becoming a major public health issue in the next 10 years. The number of people over the age of 40 who suffer vision loss or blindness is expected to be as follows:
- Macular Degeneration: Currently 1.8 million people, by 2020 2.9 million (62% Increase)
- Glaucoma: Currently: 2.2 million people, by 2020 3.3 million (66% Increase)
- Vision Loss From Diabetes: Currently 4.1 million people, by 2020 7.2 million (56% Increase)
In Fort Collins Optometry Finds The Same Problems Seen Nationally- But At A Lower Rate Due To Our Younger Eye Demographics
Eye Doctors Reported Some Further Vision Loss Statistics:
- Nationally, people 80 or more years old comprise 8% of the total population but have such a higher incidence of serious eye disease that their age bracket contains almost 70% of the cases of blindness
- Over 10% of eyesight cases have significant vision loss from macular degeneration
- Eye researchers found the prevalence of glaucoma is about three times higher in African Americans, and is also the leading cause of blindness in Hispanics
- About 8% of people with diabetes over the age of 40 have some eye condition that puts them at substancial risk for sight loss.
Fort Collins Eye Doctors Find A Higher Risk For Vision Loss And Macular Degeneration Due To Our Increased UV Exposure From The Mountain Altitudes In Northern Colorado
Practicing Optometry n Fort Collins I see an increase in the number of patients with macular degeneration every year. There is less filtering of ultraviolet radiation when people with active lifestyles spend time in the mountains of Northern Colorado. Optomerist reccomendations include quality sunwear, hats with brows, and spending more time outdoors before 11:00 AM and after 3:00 PM to avoid the intense UV of the midday.
Schedule Your Optometrist Visit Today-Annual Eye Exams Become More Important With Age
This research highlights the fact that many cases of sight loss can be prevented by early detecion and treatment. Nutritional supplements and new injectable drugs can often slow the progerssion of vision loss from macular degeneration. Glaucoma is more treatable than ever before, with stepped choices of multiple medication, laser surgery, and filtering surgery to drain fluid slowly from the eyes. A large number of cases of diabetes eye problems can be prevented by early lifestyle interventions, and well regulated blood sugar can delay the onset of eye problems. After 40, annual eye exams should become routine, and by age 65 seeing your eye doctor annually is essential to insure you have healthy eyes and good vision for a lifetime.
Fort Collins Eye Doctors-Dr Kisling | Your Eye Health Is Our Number One Concern
Is Marijuana Proven To Be OK For Treating Glaucoma?
From This Eye Doctors Perspective The Answer is No
Your Eyes Need Constant Eye Pressure Lowering effects to treat glaucoma and prevent blindness.
Besides the known issues of needing dosing every 2-3 hours, especially at night when pressures tend to rise there are other reasons why it is not a good idea. Current prescription medications are more efficacious without the impairment to motor skills. How marijuana interacts with blood flow to the optic nerve is largely unknown at this time. This is vital to understanding for glaucoma treatment, since your eye doctor may find normal pressures but any impairment of blood flow to the optic nerve can cause glaucoma even when the pressure is normal.
Medical and Eyecare studies are not as reliable as media hypes them to be
A widely quoted study several years ago by Dr. Donald Tashkin of UCLA determined that smoking pot did not increase the incidence of lung cancer. Unfortunately this may not be true. Marijuana smoke contains known carcinogens. Smokers inhale and hold the smoke as long as they can greatly extending the exposure to the lungs. Multiple studies have shown marijuana smokers show alterations to epithelial cells (surface cells in their lung tissue, These are changes that normally increase the risk of lung cancer and pulmonary disease.
Dr. Tashkin’s study relied on self reported information for much of data. This was not a true double blind study, the gold standard of medical research. Unfortunately, it would not be ethical to undertake such a study. There is a flaw in the logic of using patients already with lung cancer and a control group without. The population with the disease is not really a completely valid group. It would require starting with two cancer free groups, users and non users and following them over several decades. While a widely used and well accepted method was used, there is a flaw in comparing these two groups. Genetically the groups were not evaluated for consistency. Self reports introduce a significant variation, especially between a sick population and one that is healthy. The statistical analysis has not shown that smoking marijuana does not cause lung cancer, it only negates the hypothesis that marijuana smoke has a correlation with an increased risk of cancer. While it seems like a trivial difference it is not. THC may inhibit the cancer formation but it is too early to conclude that there is not an increase cancer or lung disease risk. A very small study (again flawed even more) last year showed a dramatic increase in people who smoked pot and cigarettes. Studies have shown marijuana smokers have more frequent chest illness, and a heightened risk of lung infections. The study was a good preliminary step but could turn out to be completely untrue over time.
At this stage, it is irresponsible to state that marijuana is free of risk to the lungs and risk the health of our children and young adults, or anyone for that matter.
Prozac is as common as aspirin today (and probably much safer). It is in the category of selective serotonin re uptake inhibitors which is a long winded way of saying it makes the molecule serotonin stay around longer instead of being recycled.
This allows a prolonged action of serotonin, one of the feel good molecules used to treat depression and a variety of other conditions. The eye has numerous receptor sites where serotonin acts, though they are not well understood at this time. Other prescription drugs you may have heard of somewhat similar to Prozac are Paxil, Zoloft, Cymbalta, Lexapro, and Luvox.
One thing they share in common is a tendency to mildly dilate the pupils. This is rarely a problem, but if you have been told you have” Narrow Angles” or are susceptible to angle closure glaucoma it can be a concern. Farsighted patients (Hyperopic) have smaller drainage angles for the fluid inside the eye to escape back into the general circulation. With age, the lens inside the eye grows and moves forward, further restricting the drainage channels. When you enter into a dark room or movie theater the pupil naturally dilates also. When dilated, the colored tissue known as the iris bunches up it’s outside edges. This thickens it right at the location where the fluid is supposed to drain out. In a normal eye there is plenty of extra space to compensate for this but eyes with narrow angles start to be blocked by the bunched up iris tissue. Eventually, the drainage can be completely blocked and since fluid is being produced in the eye the pressure skyrockets up.
Normally this results in an acute attack of a very painful, blurry red eye with nausea and headaches. Drugs like Prozac in a rare handful of cases have been known to push this process over the edge and precipitate angle closure glaucoma attacks. While highly unlikely, if you have narrow angles you should be aware of this, since this form of glaucoma is curable with early treatment.
The other possibility from this category of drugs is a transient rise in eye pressure for several weeks (though some cases report drops in pressure). If you have just started Prozac or a similar drug and your eye pressure readings are a little high, discuss this with your optometrist and have the pressures retested in 2-3 weeks. There is usually a return to normal if it is a mild medication induced increase.
A retest in a few weeks could save you money on unnecessary treatment and testing.
Finally, be happy that we have medications that have such better safety profiles than the prior generation.
The Optometric Nutrition Society
A Professional Society Whose Time Has Come
Dr.David Kisling of Fort Collins,Colorado has become an active member of The Optometric Nutrition Society. Lifestyle modification and nutrient intake are proving to play an important role in vision health and eye disease prevention. Several studies have shown a correlation with nutrition and chronic eye disease. This area of study has become a focus of primary vision care doctors.
The purpose of the Optometric Nutrition Society is to:
To promote excellence in the care of optometric patients through nutritional support of eye health and the prevention and control of ocular and systemic disease.
To sponsor professional symposia as well as a website, and to generate materials to educate professionals regarding the role of nutrition in systemic and ocular health.
To provide a collegial atmosphere where health care professionals can exchange ideas and concepts regarding nutritional influences on vision.
Provide a resource pool of clinically relevant refereed studies that support the role of safe nutritional support for the management of ocular and systemic disease.
To monitor and validate claims made by industry regarding the quality and efficacy of nutritional supplements.
To encourage the inclusion of nutrition education in the curricula of optometry schools.
The society closely monitors peer-reviewed published science on nutritional influence on eye health, as well as safety and ethical issues regarding specific micronutrients included in supplements being marketed to vision patients.
For more information contact:
Name: Dr David Kisling, O.D.
Address 181 West Boardwalk Ste. 201
Fort Collins,CO. 80525
Phone: (970) 226-0959
Email info@harmonyeyes.net
The leading causes of blindness in the U.S are diabetic related eye complications, glaucoma, and macular degeneration. Cataracts are generally listed as the number one cause but this is somewhat misleading.
Cataracts effect in excess of 20 million people but most cataracts are treatable with modern surgical techniques and artificial lens implants. The complication rate is low. While some cataracts may be inoperable due to other health problems, most can be successfully removed. Many cases of blindness attributed to cataracts are actually due to preexisting retinal problems such as macular degeneration and advanced glaucoma. If the retina is not healthy to start with, removing the cataract will not restore vision, and the low level of vision categorized as blindness is actually not due to cataracts. The cost of cataract surgery is a barrier to treatment to the uninsured and can account for some of the large numbers of blindness attributed to cataracts.
Next to cataracts, diabetic complications in the eye do result in blindness in over 4 million people. With the current increase in obesity in our culture, especially in youth, this is a serious concern for the future. Most diabetes related blindness is due to changes in the blood vessels in the retina that causes microanuysms, bleeding, proliferation of fragile new blood vessels, and detachments of the retinal tissue. There is a correlation with how many years the diabetes has been present and how well the blood sugar has been controlled. Early treatment of retinal complications is a proven method of greatly lowering the incidence of blindness.
Glaucoma also is responsible for several million cases of blindness. Glaucoma has traditionally been thought of as high pressure in the eye. Today it is gradually becoming viewed as a circulatory problems to the optic nerve and a neurodegenerative disease, where the death of the nerves are a vital part of the disease. This will greatly alter our treatment regimins at some point in the future as we transition to using drugs to protect the nerve health and increase blood circulation.
All three of these conditions are primarily a condition of aging and as the population ages the incidence is increasing. All three are also highly likely to prove amendable to lifestlye and nutritional intervetion at early stages.
Protection of the lens in the eye from UV exposure and enrichment of the diet with food and nutriional supplements containing lutein and zeaxanthin appears to show promise. Eating a diet with a low glycemic index (limiting refined sugars, eating complex carbohydrates like whole grains, and lost of vegetables) also will probably be shown to reduce cataracts. Finally, like the other leading causes of blindness, reducing obesity will reduce cataract fomration. While vitaimin E and C have been shown in recent studies not to reduce cataract formation. I do not beleive this will prove to be true with repeated studies. I do beleive antioxidants will be shown over time to be useful but it may be true in the context of whole foods and balanced diets, not in the form of supplementation.
Macualr degeneration has it’s proven formula manufactured by Bausc & Lomb under the name of Preservision which was shown in the initial Age Related Eye Disease Study (A.R.E.D.S.) to slow the progression of the mild form of macualr degeneration to the severe form. The supplements in the original formula are:
PRESERVISION
Vitamin A (beta-carotene)
Vitamin C (ascorbic acid )
Vitamin E (dl-Alpha Tocopheryl Acetate)
zinc oxide
copper cupric oxide
While a studies have shown an increase in lung cancer in smokers taking Vitamin A (beta-carotene) supplements, this is not a clear cut finding and may be proven wrong in the future. Currently supplements are being made both with and without Vitamin A. The exciting new news on the macular degeneration front is Age Related Eye Disease Study 2 -, which is testing the addition of lutein and zeaxanthin. Omega 3 fatty acids are also currently being looked at as a preventative supllements for macualr degeneration. Oxidative damage is presumably a major factor in macualr degeneration but it, like every other disease is usually not a simple one fix all type of propostition. Focusing on lifestlye prevention and nutrition and not late miracle cures should be a large part of our research expenditures.
It is still incredibly important to remember that many cases of all three of these conditions are due to genetic, environmental,coexisting health conditions, social, and mental health conditions out of our hands; and to place the blame or burden on an individual for their own illness is one of the cruelest and narcissistic attitudes we can take. On the other hand, we are enterning a new era where we can offer new forms of advice and interventions at an early age.
Glaucoma is at an earlier stage where we know less. While we will address individuals supplements and conditions in laters articles, for now a few peices of the clue. Vitamin C loweres eye pressure in some people due to osmotic pressure. Ginko may increase blood flow to the optice nerve. Forskolin comes from a plant named Coleus forskohlii and it has been used to lower intraocular pressure.
You can alter your lifestlye and nutrition and in conjunction with your prevetative eye exams from your family eye doctor thier is a good chance you can expect a lifetime of healthy eyesight. Fortunatly, most vision insurance plans, including Vision Service Plan and Medicare are recognizing the need for annual eye check ups for theses diseases.
As a final note, we feel so strongly about preventing blindness, if you have lost your job the last 12 months and are unisured we will work with you to manage your glaucoama for free for the remaider of the year if we feel we can help your case.
Welcome to Dr Kisling-Fort Collins Eye Doctors Choice Website. Our vision is to be the premier resource for answers about your eye symptoms and eye problems. You can use the search box to find answers to questions about your eyes. You will find articles on contact lenses, dry eyes, glaucoma, eye nutrition pinkeye ad other eye diseases.
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If there is a topic you would like more information on please feel free to leave a request in the comment box. Thank you for visiting our website and we hope we can become your partner in preventative eyecare for a lifetime of healthy eyesight!
Glaucoma is a complex multi-factorial disease. In plain English, that means it is not one disease and not caused by one factor only. Recent knowledge has made us acutely aware that eye pressure is not the determining factor in the diagnosis of glaucoma. When the pressure inside the eye was above 21 in the past glaucoma was thought to be present. Today we know that some individuals will never develop glaucoma even though their eye pressure readings may stay in the 30′s while other patients cannot tolerate normal pressures without sustaining sight loss. Glaucoma is more of a vascular disease of the optic nerve of the eye. When the auto-regulation of the blood supply starts to fail, vision begins degrading. High eye pressures do cause compression of the blood vessels supplying the nerve, but healthy blood vessels with good autoregulatory mechanisms can sustain very high pressures. Eye pressure is not static and can vary throughout the day. When we read it once when we are at the optometrists office it is only a thin slice of what your pressure range could be over a 24 hour period.
The Human Genome Project mapped the human gene structure and was an enormous undertaking completed in 2003 taking 13 years and sequencing over 3 billion codes of base pair information. This has opened the doors to tremendous future strides in treating all diseases. There is a chromosome with a gene that codes for the production of a protein called myocilin-a protein that makes up part of the structure of the trabecular meshwork. This meshwork is responsible for keeping the fluid balance in check by allowing continual drainage. When something goes awry with the drainage the pressure goes up increasing your risk for developing glaucoma. Ocugene is a company that has developed a test for defects in the myocilin/TIGR gene(GLC1A). Unfortunately, this gene is only responsible for about 4% of the cases of glaucoma. It can be useful when there is a suspected family history since patients with this genetic marker tend to have rapidly developing glaucoma and should be treated more aggressively. It also tends to be more commonly associated with glaucoma under the age of 40.The WDR36 (GLC1G) gene has also had mutations that appear to be associated with glaucoma. The optieurin gene(GLC1E) has reportedly been associated with an increased incidence of glaucoma in patients with normal pressures. One uncommon form of glaucoma know as exfoliation has also has seen the development of a genetic marker test, but due to the rarity of this condition it is not widely used .
All together, probably less than 10% of glaucoma has a direct genetic cause, and due to the expense of genetic testing it is rarely utilized. The complexity of testing is compounded by the fact that numerous defects at each gene can ocurr, and sometimes it may take two or more genes with flaws to create glaucoma. Even the most accepted genetic factor, the myocilin gene, may cause glaucoma from defects in areas other than the trabecular meshwork. It is very early in the age of genomics. Perhaps the greatest benefits will not be in diagnosing glaucoma but in tailoring treatment and actually curing some forms of glaucoma in the future.
General health issues are the most important risk factors, and some you can control. Smoking and cardiovascular diseases are high risk factors for developing glaucoma. Make sure you stay fit and have well controlled blood pressure. Keep preventative appointment and regular eye exams to monitor the eye pressure. Age is a risk factor but consider it a good one. A longer life is usually better all things considered! Most vision insurance plans like Vision Service Plan, Medicare, and many others cover preventative annual eye examinations.
A cataract is a clouding, opacification, yellowing, or accumulation of fluid in the lens of the eye that results in a loss of vision that interferes with your lifestyle. Most cataracts are related to aging, and by the time you reach the age of 70 it is almost universal to have some early signs of cataracts.
Age related cataract may occur in one eye first but with time will usually be present in both.
The lens is a clear part of the eye that helps to focus light, or an image, on the retina. The retina is the light-sensitive tissue at the back of the eye that is lined with the photoreceptor cells registering light.
A healthy lens is transparent and passes most of the light to the retina, filtering out some UV. The retinal photoreceptor cells change light into nerve signals that are sent to the brain area in the back of the head.
When the lens becomes cloudy from a cataract, the image you see will be blurred.
Most cataracts are related to aging, but some are have other causes such as trauma, eye diseases,and developmental abnormalities. Eye surgery for glaucoma and other conditions can lead to cataract formation. Certain health conditions like diabetes can also cause cataracts, occasionally very rapidly and in some instances reversible. Prescription steroid medications used long term can result in cataract development. Traumatic cataracts result after serious eye injuries but usually will not progress over time like age related cataracts. Infants occasionally are born with cataracts or develop them in early childhood, often in both eyes. These cataracts may be so small that they do not affect vision. While technically a cataract, I feel opacities need to cause lifestyle interruptions before they should be labeled as a cataract. If they do, the lenses may need to be removed. Radiation exposure can result in cataracts if the dose is high enough or accumulates over repeated exposure.
The lens lies behind the iris and the pupil, the black opening you see in the eyes. The lens adjusts the eye’s focus like the zoom on a camera, allowing us to see things clearly both up close and far away. The lens is made of mostly water with small amounts of protein and other substances. The protein is arranged in precise layers that keep the lens clear and lets light pass through it. When this pattern is disrupted vision becomes hazy and blurry.
There are steps you can take to reduce your risk of developing cataracts. Smoking is a major risk factor for cataract development as well as most causes of blindness. Reducing your UV sun exposure by wearing quality sunglases that meet A.N.S.I. standards is helpful. Sunwear that wraps and blocks sun exposure from the side is even more helpful.
Although research studies have given mixed results, time will probably bear out a protective effect of antioxidants on the lens tissue. Supplementation with vitamin C, lutein, zeaxanthin, and vitamin E likely will be shown to reduce cataract development. Eating foods that are complex carbohydrates such as whole grains and less refined foods with a lower glycemic index are associated with a decreased risk of cataract formation. Leafy green leafy vegetables, fruit, and other foods with antioxidants are always the best source of supplements.
Annual comprehensive dilated eye health exams are vital to monitor for cataracts and allow your optometrist to check for signs of macular degeneration, glaucoma, and other eye diseases. Early treatment and detection of eye disease may save your sight and life!
The most common symptoms of a cataract are:
- Cloudy or blurry vision.
- Colors seem faded.
- Glare. Headlights, lamps, or sunlight may appear too bright. A halo may appear around lights.
- Poor night vision.
- Frequent prescription changes in your eyeglasses or contact lenses as your eyes become more nearsighted.
Cataracts do not require surgery until they interfere with your lifestyle. In rare cases, the lens can rupture causing serious problems. This is almost unheard of today as eye doctors are widely accessible in all areas of the United States. A new eyeglasses prescription, brighter lighting, anti-glare sunglasses, or magnifying lenses can all be used to help in the interim period. Cataract surgery has a success rate over 95% today and replaces the lens with an artificial implant. Frequently your prescription for distance will be significantly reduced after surgery. Many patients find they have only occasional need for glasses for distance. Some lens implants available today provide some reading capacity also. Most of the time delaying cataract surgery will not cause long-term damage to your eye so you should not feel a need to rush into surgery.
Cataract removal may become essential when other eye diseases in the eye such as macular degeneration or diabetic related complications need to be visualized well to be followed. Even if your eye doctor tells you you have a cataract, your cataract may never develop to the point where surgery is required.
If you have cataracts in both eyes, the surgery may be necessary on one eye only for good vision. If surgery is required on both eyes it will be done at separate times several months apart. This is a much safer approach should complications occur, and allows for refinement of procedure if the first outcome is slightly off.
As with any surgery, cataract surgery does have some risks. Infection inside the eye is the most serious, but rare complication. Lenses may be displaced, cause damage to other tissues in the eye, and the retina tissue in the back of the eye may have swelling or detachments. Some prescription medications predispose you to problems during surgery so be sure to discuss all of your prescriptions with your eye doctor well in advance of eye surgery. Flomax, a prescription used to treat benign prostatic hyperplasia (BPH) has been associated with Intraoperative Floppy Iris Syndrome (IFIS). IFIS can cause problems during cataract surgery so you should be sure to inform your eye doctor if you are any prostate medications. Before cataract surgery, your doctor may ask you to temporarily stop taking certain medications that increase the risk of bleeding during surgery. Over the counter drugs like aspirin and advil may fall in this category. After surgery, you must keep your eye clean, wash your hands before touching your eye, and use the prescribed medications to help minimize the risk of infection. Serious infection can result in loss of vision.
Cataract surgery slightly increases your risk of retinal detachment. Other eye disorders, such as high myopia (nearsightedness), can further increase your risk of retinal detachment after cataract surgery. One sign of a retinal detachment is a sudden increase in flashes or floaters. Floaters are little “cobwebs” or specks that seem to float about in your field of vision. If you notice a sudden increase in floaters or flashes, call your optometrist immediately. A retinal detachment is a medical emergency. If necessary, go to an emergency service or hospital. Early treatment for retinal detachment often can prevent permanent loss of vision.
For a few days after surgery, your eye doctor may ask you to use several eyedrops to help healing and decrease the risk of infection. You will need to wear an eye shield or eyeglasses to help protect your eye. Avoid rubbing or pressing on your eye. Sun glasses will be needed to protect your eyes from the bright glare we have in Fort Collins and Northern Colorado.
When you are home, try not to bend from the waist to pick up objects on the floor. Do not lift any heavy objects. You can walk, climb stairs, and do light household chores.
In most cases, healing will be complete within eight weeks. Your doctor will schedule exams to check on your progress.
Problems after surgery are rare, but they can occur. These problems can include infection, bleeding, inflammation (pain, redness, swelling), loss of vision, double vision, and high or low eye pressure. With prompt medical attention, these problems can usually be treated successfully.
Months or years after cataract surgery cell growth can occur on the artificial lens obscuring vision. This is frequently referred to as after cataracts. A simple, brief laser procedure done in the office quickly resolves this problem.
Cataracts surgery is one of the most successful procedures done today. While you don’t want to rush into any surgery you can rest assured knowing if your vision does become problematic you have a good treatment option available. Medicare will cover cataract surgery when your eyesight has degraded to a designated level. Many types of vision insurance, including Vision Service Plan, provide coverage of cataract surgery under some of their policies. You will need to check with your provider to find out what is covered under your plan. Some types of lens implants are usually excluded.
The Ocular Hypertension Study was the first well documented research to justify treatment of patients with high pressures in the eyes. After years of unvalidated therapy the results were conclusive, early treatment was preventative. Ironically, today intraocular pressure has become less definitive measure for glaucoma as blood flow disruptions to the optic nerve appear to be more important. The ocular hypertension treatment study is still groundbreaking research that means patients with high pressures should be treated sooner to prevent the development of glaucoma. Furthermore, early treatment has been shown in some cases to reverse early damage that can be detected by analyzing the nerve fibers inside the eye.
Results–Ocular Hypertension Treatment Study (OHTS)
Background
Glaucoma is a group of diseases that can lead to damage to the eye’s optic nerve and result in blindness. Open-angle glaucoma, the most common form of glaucoma, is one of the leading causes of blindness in the United States and the number one cause of blindness among African Americans. Glaucoma usually has no early symptoms, and by the time people experience problems with their vision, they usually have lost a significant amount of their sight.
How Open-Angle Glaucoma Develops
Increased pressure inside the eye is an important cause of open-angle glaucoma. In the front of the eye is a space called the anterior chamber. A clear fluid flows continuously in and out of this space and nourishes nearby tissues. The fluid leaves the anterior chamber at the angle where the cornea and iris meet. When the fluid reaches the angle, it flows through a spongy meshwork, like a drain, and leaves the eye.
Open-angle glaucoma gets its name because the angle that allows fluid to drain out of the anterior chamber is open. However, for unknown reasons, the fluid passes too slowly through the meshwork drain. As the fluid builds up, the pressure inside the eye rises. Elevated eye pressure can damage the optic nerve; a healthy optic nerve is necessary for good vision. When the optic nerve is damaged from increased pressure, glaucoma — and vision loss — are the result.
At first, open-angle glaucoma has no symptoms. People are not aware that glaucoma is affecting their vision, and there is no pain. When glaucoma remains untreated, people may notice that although they see things clearly in front of them, they miss objects to the side and out of the corner of their eye. Without treatment, people with glaucoma may find that they have no side vision. Over time, the remaining vision may decrease until there is no vision left.
The Ocular Hypertension Treatment Study
Prior to the Ocular Hypertension Treatment Study, there was no clear evidence as to whether reducing elevated pressure in the eye would delay or prevent the onset of glaucoma. Elevated pressure in the eye, a common condition affecting three to six million people in the United States, is thought to be the leading risk factor for development of open-angle glaucoma. For the purposes of this study, ocular hypertension — which can be diagnosed by an eye care professional — was defined as pressure of 24 mm Hg or greater in at least one eye.
Despite the lack of convincing evidence, approximately 1.5 million people in the U.S. with elevated eye pressure and no glaucoma damage are being treated with medications that lower this pressure. There was a need for a well-controlled clinical trial to determine whether medical reduction of elevated intraocular pressure could delay or prevent the onset of glaucoma. The resulting data would enable clinicians and patients to make rational choices and health care planners ensure that medical resources were being allocated in a safe and cost-effective manner.
The primary goal of the Ocular Hypertension Treatment Study was to determine whether reducing elevated eye pressure delayed or prevented the onset of glaucoma and subsequent vision loss in people at risk of developing the disease. Patient recruitment took place between February 28, 1994 and October 31, 1996. A total of 1636 individuals were selected to participate; 817 were assigned to receive topical ocular medication (eye drops), and 819 were assigned to observation. All of the medications used in the study were commercially available.
Scientists found that eye drops used to reduce pressure inside the eye were effective in delaying the onset of primary open-angle glaucoma. After five years, researchers found that treatment reduced the onset of primary open angle glaucoma by more than 50 percent.
The Ocular Hypertension Treatment Study is the first large-scale study to demonstrate that lowering eye pressure — a risk factor for the development of primary open-angle glaucoma — can safely and effectively delay and possibly prevent the disease.
High Risk Factors for Glaucoma
In a companion paper, also published in the June 2002 issue of Archives of Ophthalmology, the authors report finding several factors predictive of those who developed primary open angle glaucoma. These included personal risk factors, such as older age and African descent, as well as ocular risk factors, such as higher eye pressure, certain characteristics in the anatomy of the optic nerve, and thinness of the cornea. The authors note that “corneal thickness provides new information about the risk of developing primary open-angle glaucoma and we recommend its measurement in the clinical evaluation of patients with ocular hypertension.”
The authors also point out that the predictive factors for glaucoma, as identified in the Ocular Hypertension Treatment Study, “are most likely to be helpful for assessing the risk of patients who resemble the study participants, i.e. ocular hypertensive individuals with eye pressure between 24 and 32 mm Hg and no evidence of glaucoma damage.” Only about two percent of Americans have these high levels of pressure in at least one eye.
The authors conclude by saying that the study results “suggest that a clinician caring for an ocular hypertensive patient can assess that individual’s risk” for developing glaucoma by considering age, race, eye pressure, optic nerve anatomy, and central corneal thickness. By considering these factors, “the clinician can identify patients who are at moderate to high risk for developing [glaucoma] and who are more likely to benefit from early medical treatment,” the authors state.
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