Glaucoma is not an unheard term for many but very few can relate it to vision loss because the awareness regarding this disease is very low. A very complicated disease damages the optic nerves causing irreversible and progressive loss of vision. Surprisingly glaucoma stands second when it comes to leading causes of blindness. Around three million people in the world have to battle this type of eye problem that causes structural injury as well as functional damage to the optic nerve head within the eye.
- Glaucoma is not one particular eye disease but a group of diseases that damages the optic nerve.
- The optic nerve functions as the image carrier and works from the specialized tissue that senses light-retina to the brain so that we can see things.
- Eye pressure is the leading cause of damage to the delicate nerve fibers that are present within the optic nerve.
- As the number of damaged nerve fibers increases, blind spots, start developing in the field of the vision.
- Once the nerve is damaged and the vision is lost, it is for permanent.
- In rare cases, when the complete optic nerve is destroyed, total blindness results.
- Early detection is the only way of preventing vision loss caused due to glaucoma.
Apart from being one of the least known eye diseases, glaucoma is also one of the most misunderstood diseases.People take it seriously only when the damage is already done which is very sad. Here are the four key facts that everyone should know about this blindness-causing disease.
Glaucoma can cause blindness if it is not treated on time. Unfortunately more than 10 percent people who suffer from glaucoma still lose their vision even after proper treatment.
- No sure shot cure for this disease has been found yet and hence prevention is the only way to stop loss of vision as much possible. Usually, medication and surgery help in halting the further vision loss.
Note: Patients suffering from open-angle glaucoma needs monitoring all through their life.
- From babies to senior persons, each one of you can suffer from glaucoma irrespective of age or gender. Although older people are more at risk of getting this disease, a recent survey has revealed that one out of every 10,000 babies to suffer from glaucoma. And the survey further reveals that young adults especially African Americans are more at risk of acquiring glaucoma.
- Glaucoma is a silent destroyer of vision and sometimes may not cause any symptoms at all. This is truer if you are suffering from open-angle glaucoma. Even when the pressure on the eyes increases it, does not cause any pain as the loss of vision starts from the peripheral side of the eye. Glaucoma testing is the only way to halt the progress of vision loss.
Types of Glaucoma :
Broadly, glaucoma is divided into two categories:
- Open-Angle Glaucoma
- Closed Angle Glaucoma
Based on these two categories glaucoma is further divided into different types as follows:
Types of Closed Angle Glaucoma
- Angle-closure glaucoma: In this mechanical problem, the drainage angle occurs obstructing the iris drainage angle, which is the colored part present in the front area of the eye.
- Acute Angle Closure Glaucoma: In this disease, the intraocular pressure increases suddenly in the peripheral drainage angle region. What is more alarming that such type of a condition is highly risky as it causes blindness within hours and can be only terminated or prevented by a laser procedure known as peripheral laser iridotomy.
- Chronic Angle-Closure Glaucoma: In this condition, the iris slowly obstructs the eye drainage angle. This disease causes vision loss in a progressive way and is found to be particularly common among individuals suffering from farsightedness.
- Secondary Angle-Closure Glaucoma: This is usually caused due to trauma or some similar reason because of which the lens placed within the eye is displaced in the forward direction.
Types of Open-Angle Glaucoma
In this type of glaucoma, it seems that drainage angle of the eye is wrongly placed even if it appears normal and open when seen even under the microscope.
- Primary Open Angle Glaucoma: Although the drainage angle is open, it still does not allow the fluid to come out as much it should. The causes of this are unknown and sometimes seem to be running in the families especially among the African Americans.
- Low-pressure Glaucoma: In this condition, the intraocular pressure is normal even then, the optic nerve is damaged leading to vision loss. In some cases, the cause is considered abnormally thin corneas. Other conditions are mostly caused because of lack of adequate blood flow to the optic nerve due to the presence of several conditions such as heart failure, Raynaud's disease, migraine and sleep apnea.
Note: Investigating health experts are of the opinion that this condition is sometimes not related to glaucoma but is rather a type of progressive Anterior Ischemic Optic Neuropathy or AION that develops slowly and steadily over a period of time.
- Congenital Glaucoma: This type of glaucoma occurs in very young children and even infants due to abnormally developed drainage angle. The symptoms in small children and infants include big eyes having cloudy corneas that are very sensitive to light.
Types of Secondary Open-Angle Glaucoma
Secondary open-angle glaucoma is of different types and is caused as a result of abnormal deposits of various materials in the traumatic damage, drainage angle or abnormal blood vessel growth.
- Exfoliative Glaucoma: When the fibrillary materials slowly deposit restricting the adequate fluid drainage this type of eye disease occurs. It is most common among North European adults.
- Pigmentary Glaucoma: In this condition, the drainage structures of the eye are affected as the pigment within the iris is dislodged. This mostly affects young myopic people, especially men.
- Angle Recession Glaucoma: In this type of glaucoma, scar tissue that has been formed due to previous trauma restricts the outflow of the fluid. Many times, it takes years or decades for such type of glaucoma to develop from the original injury.
- Steroid-Induced Glaucoma: When a patient is prescribed steroid medications such as prednisone as a part of systemic or topical treatment, it can cause the intraocular pressure to go up. When this pressure becomes high enough or stays for longer duration it damages the optic nerve and finally causes vision loss.
- Neovascular Glaucoma: It is usually caused due to different health problems and disorders such as diabetes. In this case, blood vessels on the iris proliferate stopping the drainage of the fluid.
Causes of Glaucoma
- The basic cause of all types of glaucoma is a loss of ability of the eye to balance the production of internal intraocular fluid and the amount of fluid that needs to be drained out.
- In addition, depending upon the type of glaucoma the causes may differ accordingly.
- However, for better understanding, you must know that just as the football or even a basketball you use for playing requires adequate air pressure to maintain its round shape similarly, the internal fluid pressure maintains the sphere-shape of the eyeball and also its ability to see.
- But when the eye loses this ability to balance the intraocular pressure it can lead to glaucoma.
- Poor blood flow can also cause glaucoma as lack of adequate amount of blood supply can lead to the formation of blind spots or scotomas that develop to block the visual field and cause glaucoma.
A recent study by UK researchers have revealed that build up of beta-amyloid-a type of protein in the retina of the eye and in the brain tissue is directly associated with the development of glaucoma and Alzheimer's.
How to Detect Glaucoma
The most trusted way of preventing vision loss through glaucoma is early detection. Complete eye exam conducted regularly can only protect your eyes from damage by glaucoma. Eye specialists trust five common tests for detecting this eye problem. Most of these detection tests rely especially on the structural damage examination of the optic nerve along with measuring other visual functions. For an accurate evaluation of the structure and the visual function, highly advanced devices based on the computer are used that includes:
- Confocal scanning laser
- Scanning laser polarimetry
- Optical coherence tomography
These detection tests qualitatively assess the visual function and the structural damage including standard automated perimetry and other selective techniques such as frequency-doubling technology perimetry and short-wavelength automated perimetry.
When Should You Go for the Detection?
Since regular examination is the only way to prevent glaucoma, you should increase the frequency of eye testing as you age.
- In every two to four years before the age of 40
- In every one to three years in between the age of 40 to 54
- In every one to two years in between the age of 55 to 64
- In every six months to one year after you complete 65 years of age
Note: A person with high-risk factors should conduct the test almost every year after the age of 35 years.
Comprehensive Examination of Glaucoma
Eye experts check the following factors before finally diagnosing glaucoma so that the diagnosis is accurate and safe.
|Name of the Test||Part of the Eye to be Examined|
|Tonometry||Inner eye pressure|
|Ophthalmoscopy or dilated eye exam||Color and shape of the optic nerve|
|Perimetry or visual field test||Complete vision field|
|Gonioscopy||The angle within the eye where cornea and iris meet|
- During this type of detection, eyes are made numb using eye drops and a device known as tonometer is used to measure the pressure within the eye.
- Pressure is applied during the process to the eye using a small device or warm air puff.
- Usually, the air pressure is in between 12-22 mm Hg and it has been found that in most of the cases the glaucoma is diagnosed above the 20mm Hg pressure.
- During this type of detection, eye drops are put in the eyes for dilating the pupils.
- This helps the doctors to see through the eyes and examine the color and shape of the optic nerve.
- The eye specialist uses a small device that has a light at its end and also can magnify the optic nerve for a better view.
- If your doctor finds that the optic nerve does not look normal or the intraocular pressure is abnormal then he will ask you to carry on gonioscopy and perimetry tests.
- This type of visual field test provides you a complete map of the field of the vision.
- This test confirms whether your vision has been damaged by glaucoma or not.
- During the process, you are required to look ahead straight and then make an indication when a light is allowed to pass through your side vision or peripheral vision.
- This helps to make an accurate vision map.
- Many times doctors repeat the test so that the results are accurate.
Note: People usually get concerned when they do not see any light but this might be because the light is moving around your blind spot. However, this does not indicate that you have a damaged vision.
- During this diagnostic exam, eyes are made numb using eye-drops and a contact lens is placed gently on the eye.
- This hand-held contact lens comes with a mirror that clearly reflects whether the angle formed between the cornea and the iris is blocked or closed.
- This is a very simple and painless test in which pachymeter-a probe is placed gently in front of the cornea so that the thickness can be measured accurately.
- This test is usually recommended to diagnose the influence of the thickness of the cornea on the eye pressure.
- The procedure requires very short time and measurement of both the eyes take only one minute.
Treatment for Glaucoma
Glaucoma has no cure, which makes prevention the only way to control its onset. However, there are certain treatments that can stop the progress of glaucoma although no treatment can bring back the vision lost due to this disease. You can always slow down the progress of glaucoma by using different medications. Regular treatments include:
- These have to be used on regular basis and are one of the most common of all the treatments.
- Sometimes pills are prescribed in case of eye drops.
- The type of eye drops varies depending upon the type of glaucoma the patient is suffering from.
- In laser iridotomy, a hole is made in the iris (colored eye part) so that the fluid is allowed to flow as it normally does.
- This therapy is used for draining the fluid in closed or narrow angles glaucoma.
- This type of laser procedure is carried out in case of eyes having open angles.
- It is not necessary for the person to suffer from glaucoma to carry out this treatment.
- This therapy is suggested to reduce the number of eye drops or multiple eyes drops a patient has been suggested as a part of the treatment.
- Some doctors suggest it as a primary or initial therapy for restricting the progress of open-angle glaucoma.
- Laser trabeculoplasty is relatively painless, safe and quick method of reducing the pressure caused by the internal eye.
- In this treatment, the eyes are numbed using anesthetic eye drops and a mirrored contact lens is used to burn the angle so that the locked fluid is allowed to drain through the drainage channels.
- The therapy uses microscope pic laser for burning the angle.
- This therapy is usually carried out in two sessions and the second session can be months or weeks after the first one.
- However, the effect of the improved drainage lasts only for around two years as the drainage channels start to clog again requiring the patient to go for another laser trabeculoplasty session.
- Two types of laser trabeculoplasty-argon laser trabeculoplasty and selective laser trabeculoplasty is common however, the first one is not repeated as it forms a scar tissue.
- On the other hand, selective laser trabeculoplasty shows less risk of scarring and hence can be used repeatedly.
- Even then success ratio with these treatments is low and hence as an option most of the times the patient has to increase his dosage of eye drops or opt for surgical intervention.
- This type of laser therapy is also termed as cyclocryopexy, cyclophotocoagulation or ciliary body destruction.
- This highly specialized laser therapy is generally offered to patients who are suffering from poor visual potential or severe glaucoma.
- During this process, freezing or laser burns are applied to the part of the eye that develops the ciliary body or aqueous fluid.
- The laser cyclo-ablation destroys the fluid creating cells and thus the pressure on the eyes is reduced.
- This laser therapy is suggested only after all the other treatments have failed to show any result.
Glaucoma Surgery or Trabeculectomy
- This is a type of microsurgical procedure that needs to be carried out with great care.
- This surgery is carried out to treat the symptoms of glaucoma.
- Clogged trabecular meshwork's very small piece is removed during the operation so that a new opening for the drainage pathway can be created and the fluid gets a passage to exit from the eye.
- To support this drainage system, a small conjunctival tissue that works as a collecting bag is created.
- Known as filtering bleb this bag resembles a cystic that is raised under the upper lid, of the eye over the top part.
- With the help of this new drainage pathway, the fluid can leave the eye, enter the bleb or bag and then move ahead into the capillary blood circulation.
- This helps in lowering the pressure on the eye.
- Trabeculectomy is one of the most commonly performed glaucoma surgery and if all goes well it can provide great relief to the glaucoma patients by lowering the eye pressure.
Glaucoma Tubes or Implants (Aqueous shunt devices)
- These are the artificial devices used especially to provide drainage and lower the pressure on the eyes.
- Essentially prepared from plastic material, these are a form of microscopic tubes that are attached to a small plastic reservoir.
- This plate or a reservoir is inserted just beside the conjuntival tissue.
- The actual insertion or tube is located within the eye and create a new drainage pathway for the fluid to come out of the eye.
- This exiting fluid is then collected inside the reservoir just beneath the conjuntival tissue.
- This type of procedure is carried out as an alternative treatment for patients suffering from particular types of glaucoma.
Canaloplasty, Viscocoanalostomy, and Trabecutome
- These three are other alternative types of surgical procedures adopted to lower eye pressure.
- During these procedures, openings are created within the trabecular meshwork and the drainage ring is placed within the wall of the eye angle. .
- Such surgical procedures are less invasive as compared to the other forms of surgery including aqueous shunt surgery and trabeculectomy.
- However, these are not as effective as the other surgical procedures in lowering the pressure on the eye.
Note: Glaucoma surgical treatment can often lead to complications including bleeding or infection and hence sometimes the surgery is reversed in the cases that are beyond control.
What are the Warning Signs for Glaucoma?
- According to a large clinical study, trial ocular hypertensives can lead to the development of true glaucoma and the risk increases at around 2 percent every year.
- The rate can be controlled if the patients are prescribed IOP lowering eye drops.
- So, the risk can be cut off in half if the patients take the IOP treatment regularly.
But what can make you decide to start the IOP lowering eye drops? How can you know that your ocular hypertension can cause glaucoma? There are certain warning signs that you must consider for taking this decision. These include:
- Having a sibling or any blood relative with history of glaucoma damage
- African-American ethnicity
- Having visual field findings or optic nerve that lies between the normal and glaucoma border
- Being near-sighted â€“myopic
- Having thin cornea
- Suffering from a condition known as exfoliation or pigment dispersion that makes you more vulnerable to high IOP
- Note: The decision whether to choose the treatment or to stay in the treatment depends entirely on the doctor and his patient and individual risk tolerance and actual risk have to be calculated before taking the step. You must keep in mind that the risk factors or the warning signs are only indications for you to take precautions and prevent the onset of glaucoma. However, this does not mean that there is no likelihood of you getting glaucoma if your body does not show any such warning signs.
Risk factors for glaucoma
Here are some of the risk factors that increase the chances of acquiring glaucoma in a person. These include:
1.Family History It is a common known fact that medical history of a family plays an important role in the diseases you can suffer from. Recent researches suggest that there is a possibility that you can inherit glaucoma. However, this does not mean that if your either parents or close relatives have suffered from glaucoma you will definitely get it. But it is sure that you are more at risk of suffering from this eye problem.
2.Age A recent study performed by American Academy of Ophthalmology has revealed that the risk of acquiring this disease increase after you cross 50 years of age. The risk is much more in case of black people and starts increasing when they are in their forties. However one this is true that you can suffer from this eye condition at any age.
3.Race Some races are more at risk of acquiring glaucoma. For example, open-angle glaucoma is the leading reason of vision loss in black people. Moreover, people belonging to Caucasian race are six to eight times more vulnerable to this type of glaucoma. The risk keeps on increasing as the black people cross their forties. On the other hand, Asians and Eskimos are at greater risk of developing closed-angle glaucoma as compared to the other races.
4.High Intraocular Pressure Individuals who suffer from elevated intraocular pressure IOP are more at risk of developing this eye condition. Elevated intraocular pressure means the pressure is more than 21 mm Hg. But even people having normal pressure have been found to develop glaucoma.
5.Hypertension High blood pressure also can contribute in increasing the risk of glaucoma. But the studies are yet to confirm this.
6.Thin Cornea A large clinical trial conducted recently has found out that patients having thinner corneas are vulnerable to developing glaucoma.It has also been discovered that thin corneas are more common among African-Americans than in Caucasians.
7.Diabetes Some health experts connect diabetes to glaucoma, however; there has been no evidence to suggest the linkage.
8.Long Term use of Steroid/Cortisone Use of steroid and cortisone for a prolonged period can increase the risk of glaucoma.
9.Eye Surgery or Previous Injury to Eye Injury to an eye can damage the internal structures of the eye causing impairment in the fluid drainage. Complications during the eye surgery can also many times lead to glaucoma.
10.Refractive Errors If you are myopic, you face the additional risk of developing open-angle glaucoma. In case you are hyperopic then you are more at risk of getting closed-angle glaucoma.
11.History of Shock or Severe Anemia Patient with a history of shock or severe anemia has been found to face an increased risk of developing glaucoma.
12.Insufficient Blood Flow or Cardiovascular Disease People suffering from conditions leading to a decreased flow of blood to the eye and brain or those suffering from cardiovascular disease also have increased the possibility of acquiring glaucoma.
13.Obesity Obesity is also known to increase the glaucoma risk.
Diet for Glaucoma-Some Important Facts
Until today, no research or study has concluded that a specific food and glaucoma has some connection. But just as you believe and has been proved right in almost all kinds of diseases, what you eat as well as drink has major impact on your health. Studies have also shown that even genetic diseases can be confined from developing to their full effect with prior changes in the diet. Here are some interesting facts that you need to consider while planning your diet to prevent the onset of glaucoma:
Limit Caffeine Intake According to some studies, intake of caffeine in a significant amount of short duration has a tendency to elevate the intraocular eye pressure slightly for a couple of hours. But studies also show that caffeine still does not cause meaningful influence on IOP.This means that people who are at increased risk of developing glaucoma should limit their intake of caffeine to be on the safer side.
Drinking Small Amount of Water Onetime A new study has revealed that more than 80 percent of the glaucoma patients who are used to consuming an entire water quart in twenty minutes span experience elevation in IOP as compared to the other 20 percent people who do not suffer from glaucoma. Since there have been a lot of hues and cry commercially on the social media and internet about the importance of drinking at least eight glasses per day, patients with glaucoma should make sure that they do not consume the water in a large amount at one go. They should drink water in small amount all through the day.
Know More about What You Eat This is a general conception that carrots are too good for eyes and protect your vision. However, the latest studies by senior staff ophthalmologist, G. Pratt, MD at Scripps Memorial Hospital in collaboration with the University of California, San Diego's assistant clinical professor show that carrots may not be playing an important role in protecting vision as once was thought.The high beta-carotene, which is a type of antioxidant, is not found in the eye and hence carrot's contribution to preventing vision loss can be limited.
Nutrients in Spinach On the other hand, spinach that is rich in zeaxanthin and lutein-the two antioxidants can contribute more in enhancing the health of the eyes as these two antioxidants are found in higher amounts in the eyes. Health experts believe that these two antioxidants can help to protect the eyes against the bad impact of oxygen.That is why today, eye specialists are asking their glaucoma and cataract patients to include green leafy vegetables such as spinach more in their diet so that the supply of these two antioxidants can be increased. Spinach is also rich in other nutrients that are good at protecting vision including zinc and vitamin C, A and E.
Two Vision Protecting Diet Steps Making changes in not only what you eat but also how much you eat is equally essential for protecting your vision. You might be surprised to known that the lifestyle changes you are advised to control your high blood pressure works well to lower the pressure within your eye. Thus following a diet to control blood pressure will also help you in restricting the progress of glaucoma. Here are the two steps that are extremely beneficial in lowering the risk of developing glaucoma:
1.Lowering Insulin Levels With the increase in your insulin levels, there is increase in the blood pressure and also eye pressure. Over the time, your body can become resistant to insulin and it is a common observation that resistance to insulin-which is a common thing among patients with high blood pressure, diabetes and obesity, is directly linked to the elevation in the intraocular pressure in the eye.
What is the solution? Insulin level surges are caused by two types of food groups-grains and sugar. Even over the time whole organic grains break down to release sugar, so it is best to avoid them or restrict their use in your diet. Apart from avoiding sugar, a glaucoma patient should also avoid foods such as:
2.Regular Exercise is Must Exercise helps to lower the insulin level effectively. Regular and effective exercise programs such as yoga, sprint-burst exercises, and aerobics along with strength training exercises help to reduce the insulin level and also protect your eyesight.
What Else Can you Do Protect Your Eyesight from Glaucoma?
As a part of your eyesight protection program, you must follow certain things keeping your health, age and weight in mind. Here are some of the tips that will go a long way in protecting you from glaucoma.
1.Animal based Omega 3 fat supplement: Docosahexaenoic acid or DHA has been found to promote as well as protect the retinal function and its health. This is a type of omega-3 fat, is present in good concentration in the retina of your eyes, and has been found to be especially beneficial to prevent macular degeneration, a condition that causes blindness.
Note: Fish is rich in Omega-3 fat but due to the recent concerns about toxins and mercury, that are now an integral part of lakes, rivers and oceans, you should instead try to include krill oil in your diet to add this supplement in your diet.
2.Adding zeaxanthin and lutein to Diet: These two powerhouses, as discussed above are rich antioxidants that are known to protect your eyesight. Lutein, which is commonly found in green leafy vegetables, protects the body cells from the damage of free radical. Some of the excellent sources of these two antioxidants are collard greens, broccoli, kale; egg yolks (particularly egg yolks that are raw). Egg yolks are rich in zeaxanthin, a form of antioxidant and another carotenoid type of antioxidant- lutein.
Note: Lutein is a type of oil-soluble nutrient and hence if you consume the vegetables without butter or oil the lutein in these vegetables will not be absorbed. Hence, you need to eat some amount of healthy fat when you eat these veggies so that the lutein supplement is absorbed completely.
Egg yolks in particular are loaded with antioxidants that can protect your eyesight. However overcooking tends to damage the quality of these antioxidants in the yolk and hence you should consume the egg yolk raw either by shaking or whipping them or by poaching them with the runny yolks.
3.Trans fats are Hazardous: Trans fat have a tendency to interfere with the omega-3 fats that are present in your body which is very important for the health of your vision. Research shows that a diet that is high in trans fat can contribute in the macular degeneration thereby leading to blindness. Hence, you should avoid foods that have this harmful content such as fried foods-French fries and fried chicken, cookies, doughnuts, crackers, pastries, margarine a d almost all the baked goods and processed foods.
4.Increase Intake of Dark-Colored Berries: The European bilberry or blueberry has been found to reverse the process of macular degeneration and the bioflavonoids present in these dark-colored berries such as cranberries and blueberries are highly beneficial in protecting vision. These bioflavonoids strengthen the capillaries that supply nutrients to nerves and muscles.
Note: Although black berries are good for eyes, they also have natural sugar and hence should be eaten in moderate amount to avoid increase in the insulin levels.
Eating Foods Rich in Antioxidants
Here is a list of foods that are rich in antioxidants and essential nutrients necessary for maintaining the health of the eyes.
- Citrus fruits
- Brussels Sprouts
- Vegetable oils (wheat germ oil is especially rich in vitamin E)
- Green leafy vegetables
- Egg yolk
- Wheat and other cereal grains
- Milk fat
- Organ Meats
- Egg yolks
- Sweet potato
- Kale Turnip greens
- Whole milk
- Mustard greens
- Pink Grapefruit
- Beet greens
- Red Peppers
- Collard greens
- Cheddar cheese
- Lean Meat
- Green leafy vegetables
- Whole Bran
- Whole Cereals
Lutein and Zeaxanthin
- Collard greens
- Parsley (not dried)
- Green peas
- Brussels sprouts
- Summer squash
- Green olives
- Green beans
- Green peppers
Why is Glaucoma Spreading Rapidly? Changes in eating habits and lifestyle have contributed hugely to the increase of glaucoma cases and today this eye disease is one of the leading causes of loss of eyesight in India. Demographic survey at the national level has revealed that there are a particular group of people who are at major risk of glaucoma. These include:
- Aging Adults
- Alcohol and Drug addicts
- Obesity epidemic
Hence, it is very much important to make a massive change in the diet and also in your lifestyle. Eating and sleeping on time, eating only health benefitting fresh foods and avoiding preservatives and packaged food items is just one way of starting your journey towards strengthening your eyesight. Since eye examination is the only way of protecting your vision loss, you need to seriously make a visit to your eye expert on a regular basis after you touch 40. Since most of the glaucoma, conditions are diagnosed when the disease is in its last stage prevention should be considered as treatment and followed very seriously.
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