Eye Education
Eye disease is a major public health problem in South Africa, causing significant suffering, disability, loss of productivity, and diminished quality of life for millions of people.
Dr. Stoler and the Morningside Eye team have provided resources here to educate others about the importance of eye health, ocular examinations, and maintaining good eye health.
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Getting an eye exam is an important part of maintaining your health. It is recommended that you get a baseline eye examination at the age of 40, as this is when changes in your vision may occur. Similar to a screening for diabetes or certain cancers, a baseline eye exam at 40 reminds adults to be more aware of their eye health. Thus helping to identify signs of eye disease at an early stage when many treatments can have the greatest impact on preserving vision.
In some cases, people can be at a risk for developing an eye disease and therefore shouldn’t wait until they are 40 for a comprehensive eye exam. If you have a family history of diabetes or high blood pressure, it is advised to see and ophthalmologist (Eye M.D.).
Your Eye M.D. will determine how often you should undergo an eye exam, upon examining your eyes. As you age, it's especially important that you have your eyes checked regularly because your risk for eye disease increases. If you are 65 or older, make sure you have your eyes checked every year or two for signs of age-related eye diseases such as cataracts, age-related macular degeneration and glaucoma.
A comprehensive eye exam is relatively simple and comfortable and shouldn't take more than 45 to 90 minutes. The exam should include checks on the following:
- Your medical history. First, your doctor will ask you for an assessment of your vision and your overall health. Your family's medical history, whether you wear corrective lenses or whether you are on any medication will also be of interest to your Eye M.D.
- Your visual acuity. This is the part of an eye exam people are probably most famipar with. Your Eye M.D. will ask you to read a standardized eye chart to determine how well you see at various distances. The test is performed on one eye at a time by covering the eye not being tested.
- Your pupils. Your doctor may evaluate how your pupils respond to pght by shining a bright beam of pght through your pupils. Common pupillary reaction to this stimulus is to constrict (become smaller). If your pupils respond by dilating (widening) or there is a lack of response either way, this may indicate an underlying problem.
- Your side vision. Loss of side vision is a symptom of glaucoma. Because you may lose side vision without knowing it, this test can identify eye problems that you aren't even aware of.
- Your eye movement. This test, called ocular motipty, evaluates the movement of your eyes. Your Eye M.D. will want to ensure proper eye apgnment and ocular muscle function. Common tests measure the eyes and their abipty to move quickly in all directions and slowly track objects.
- Your prescription for corrective lenses. You will be seated and asked to view an eye chart through a device called a phoroptor, which contains different lenses. The phoroptor can help determine the best eyeglass or contact lens prescription to correct any refractive error you may have, such as myopia.
- Your eye pressure. This test, called tonometry, measures the pressure within your eye (intraocular eye pressure, or IOP). Elevated IOP is a sign of glaucoma. The test may involve a quick puff of air onto the eye, or gently applying a pressure-sensitive tip near or against your eye. Your Eye M.D. may use numbing drops for this test for your comfort.
- The front part of your eye. A type of microscope called a spt lamp is used to illuminate the front part of the eye, including the eyepds, cornea, iris and lens. This can reveal whether you are developing cataracts or have any scars or scratches on your cornea.
- Your retina and optic nerve. Your Eye M.D. will put drops in your eye to dilate, or widen, your eye. This will allow him or her to thoroughly examine your retina and optic nerve, located at the back of your eye, for signs of damage from disease. Your eyes might be temporarily sensitive to pght for a few hours after they are dilated.
- Your Eye M.D. may suggest additional testing to further examine your eye using speciapzed imaging techniques such as OCT, topography or fundus photos. These tests can be crucial in diagnosing a disease in its early stages and allow your doctor to detect abnormapties in the back of the eye, on the eye's surface or inside the eye.
Each part of the eye exam provides important information about the health of your eyes. Make sure that you are getting a complete examination as part of your commitment to your overall health.
The human eye is the most complex organ of our body. In many ways, the eye works like a digital camera: Light is focused primarily by the cornea — the clear front surface of the eye, which acts like a camera lens.
The iris of the eye is like the diaphragm of a camera. It controls the amount of light that reaches the back of the eye by automatically adjusting the size of the pupil.
The eye's crystalline lens is located directly behind the pupil and further focuses light. Through a process called accommodation, this lens helps the eye automatically focus on near and approaching objects, like an autofocus camera lens.
Light focused by the cornea and crystalline lens (and limited by the iris and pupil) then reaches the retina — the light-sensitive inner lining of the back of the eye. The retina acts like an electronic image sensor of a digital camera, converting optical images into electronic signals. The optic nerve then transmits these signals to the visual cortex — the part of the brain that controls our sense of sight.
There are other parts of the eye that plays a role in the main activity of sight. These parts are:
- Fluids such as tears or blood which lubricates or nourish the eye.
- Eye muscle which allows the eye to move.
- Eyepds and the epithepum of the cornea which protects the eye from injury
- Pain-sensing nerves in the cornea and the optic nerve behind the retina which sends sensory information to the brain.
A cataract is a cloudy area in the lens of the eye that affects vision, causing blurring, like one is looking through a dirty window. Colours and contrast sensitivity are also dulled, with bright lights causing much glare - particularly at night.
A normal lens is clear. It lets light pass to the retina, the light-sensitive tissue at the back of the eye. As a cataract develops, it becomes harder for a person to see. Vision may become cloudy or blurry, and colours may fade.
Most people develop a cataract in both eyes. One eye may be worse than the other, however, because each cataract develops at a different rate. Some people with a cataract don't notice the slow decline in colour, brightness, and contrast sensitivity. Their cataract may be small, or the changes in their vision may not bother them very much. Other people cannot see well enough to do the things they need or want to do.
Who Is Affected? Most cataracts are related to aging - cataracts are the most common cause of visual loss in adults 55 years or older. In studies, around half of Americans ages 65 to 74 have a cataract. About 70 percent of those age 75 and older have this condition. However, other conditions can increase the risk of developing cataracts. Examples include diabetes, smoking, and the use of certain medications, like corticosteroids.
How Is a Cataract Treated? Fortunately we live in a time when cataracts can be removed easily, painlessly, and with immediate improvement in vision for most patients. Surgery is used to remove a cataract when vision loss interferes with everyday activities such as driving, reading, or watching TV. If you have cataracts in both eyes, the surgery will be performed on each eye at separate times, usually 2 to 4 weeks apart.
There are various types of cataract surgery. The standard/traditional ‘phacoemulsification’ procedure, where surgical knives are used to make incisions into the eye, and ultrasound energy is used to break up the cataract, is performed in most cases to treat cataracts since the 1990’s. Today, newer-based bladeless cataract surgery has evolved to improve predictability, safety, and potential visual outcome.
Dry eyes is a condition which refers to the lack of tears or the poor quality of tears produced by the eye. This condition causes discomfort to the eye.
Tears consist of three layers. Each serving its own purpose to maintaining healthy comfortable eyes. These layers are:
- An oily layer
The oily layer is produced by the meibomian gland and forms the outer surface of the tear film. Its purpose is to smooth the tear surface and reduce evaporation of tears. - A watery layer
The watery layer –which is what we ordinarily think of as tears – is produced by the lacrimal glands in the eyelids. It cleans the eye and washes away any foreign particles or irritants. - A layer of mucus
The inner layer consists of mucus which is produced by the conjunctiva. Mucus allows the watery layer to spread evenly over the surface of the eye and helps the eye remain moist. Without mucus, tears would not stick to the eye.
The eye constantly bathes itself in tears by producing tears at a slow and steady rate, to stays moist and comfortable.
The eye uses two different methods to produce tears. It can make tears at a slow, steady rate to maintain normal eye lubrication. It can also produce a lot of tears in response to eye irritation or emotion. When a foreign body or dryness irritates the eye, or when a person cries, excessive tearing occurs.
If the tears responsible for maintaining lubrication do not keep the eye wet enough, the eye becomes irritated. Eye irritation prompts the gland that makes tears (called the lacrimal gland) to release a large volume of tears, overwhelming the tear drainage system. These excess tears then overflow from your eye.
Conditions that affect the lacrimal gland or its ducts — including autoimmune diseases like lupus and rheumatoid arthritis — lead to decreased tear secretion and dry eye.
Tear secretion may also be reduced by certain conditions that decrease corneal sensation. Diseases such as diabetes and herpes zoster are associated with decreased corneal sensation. So is long-term contact lens wear and surgery that involves making incisions in or removing tissue from the cornea.
There are a wide variety of medications which may cause dry eye by reducing tear secretion. Be sure to tell your ophthalmologist the names of all the medications you are taking, especially if you are using:
- Diuretics for high blood pressure;
- Beta-blockers for heart or high blood pressure;
- Antihistamines for allergies;
- Sleeping pills;
- Anti-anxiety medications;
- Pain relievers.
Since these medications are often necessary, the dry eye condition may have to be tolerated or treated with eye drops called artificial tears.
People with dry eye are often more likely to experience the side effects of eye medications, including artificial tears. For example, the preservatives in certain eye drops and artificial tear preparations can irritate the eye. These people may need special, preservative-free artificial tears. Another cause for dry eye is exposure to a dry, windy climate, as well as smoke and air conditioning, which can speed tear evaporation. Avoiding these irritants can offer dry eye relief.
Discomfort and pain in the eye may be associated with the following:
- Bacterial Keratitis
- Cellulitis
- Conjunctivitis (Pink Eye)
- Corneal Abrasion
- Corneal Laceration
- Corneal Ulcer
- Fuchs' Dystrophy
- Fungal Keratitis
- Glaucoma
- Herpes Keratitis
- Hyphema
- Microvascular Cranial Nerve Palsy
- Optic Neuritis
- Uveitis
It's important to remember that many people do not know they have eye disease because there are often no warning signs or symptoms, or they assume that poor sight is a natural part of growing older. Early detection and treatment of eye problems is the best way to keep your healthy vision throughout your life. In many cases, blindness and vision loss are preventable.
If you have any unusual vision symptoms, it is important that you speak with your ophthalmologist.
Glaucoma is a disease that damages your eye's optic nerve. It usually happens when fluid builds up in the front part of your eye. That extra fluid increases the pressure in your eye, damaging the optic nerve.
Glaucoma is a leading cause of blindness for people over 60 years old. But blindness from glaucoma can often be prevented with early treatment. When glaucoma develops, usually you don’t have any early symptoms and the disease progresses slowly. In this way, glaucoma can steal your sight very gradually. Fortunately, early detection and treatment (with glaucoma eye drops, glaucoma surgery or both) can help preserve your vision.
The optic nerve is connected to the retina — a layer of light-sensitive tissue lining the inside of the eye — and is made up of many nerve fibres. The optic nerve sends signals from your retina to your brain, where these signals are interpreted as the images you see. In a healthy eye, excess fluid leaves the eye through the drainage angle, keeping pressure stable.
In the healthy eye, a clear fluid called aqueous humor circulates inside the front portion of your eye. To maintain a constant healthy eye pressure, your eye continually produces a small amount of aqueous humor while an equal amount of this fluid flows out of your eye. If you have glaucoma, the aqueous humor does not flow out of the eye properly. Fluid pressure in the eye builds up and, over time, causes damage to the optic nerve fibres. If the drainage angle is blocked, excess fluid cannot flow out of the eye, causing the fluid pressure to increase.
There are many types of glaucoma, such as:
- Open-angle glaucoma
- The most common form of glaucoma is called primary open-angle glaucoma. It occurs when the trabecular meshwork of the eye gradually becomes less efficient at draining fluid. As this happens, your eye pressure, called intraocular pressure (IOP), rises. Raised eye pressure leads to damage of the optic nerve. Damage to the optic nerve can occur at different eye pressures in different patients. There is not one ‘right’ eye pressure that is the same for everyone. Your ophthalmologist establishes a target eye pressure for you that he or she predicts will protect your optic nerve from further damage. Different patients have different target pressures.
- Typically, open-angle glaucoma has no symptoms in its early stages and your vision remains normal. As the optic nerve becomes more damaged, blank spots begin to appear in your field of vision. You usually won’t notice these blank spots in your day-to-day activities until the optic nerve is significantly damaged and these spots become large. If all of the optic nerve fibres die, you will be blind.
- Half of patients with glaucoma do not have high eye pressure when first examined. Eye pressure is not always the same – it rises and falls from day to day and hour to hour. So a single eye pressure test will miss many people who have glaucoma. In addition to routine eye pressure testing, it is essential that the optic nerve be examined by an ophthalmologist for proper diagnosis.
- Normal-tension glaucoma
- Eye pressure is expressed in millimeters of mercury (mmHg), the same unit of measurement used in weather barometers. Although "normal" eye pressure is considered a measurement less than 21 mmHg, this can be misleading. Some people have a type of glaucoma called normal-tension, or low-tension glaucoma. Their eye pressure is consistently below 21 mmHg, but optic nerve damage and loss of vision still occur. People with normal-tension glaucoma are usually treated in the same way as people who have open-angle glaucoma.
- Angle-closure glaucoma (also called "closed-angle glaucoma" or "narrow-angle glaucoma")
- This type happens when someone’s iris is very close to the drainage angle in their eye. The iris can end up blocking the drainage angle. You can think of it like a piece of paper sliding over a sink drain. When the drainage angle gets completely blocked, eye pressure rises very quickly. This is called an acute attack. It is a true eye emergency, and you should call your ophthalmologist right away or you might go blind. People of Asian descent and those with hyperopia (farsightedness) tend to be more at risk for developing this form of glaucoma.
- Symptoms of an acute attack include:
- Your vision is suddenly blurry
- You have severe eye pain
- You have a headache
- You feel sick to your stomach (nausea)
- You throw up (vomit)
- You see rainbow-colored rings or halos around lights
- A closed-angle glaucoma attack is a medical emergency and must be treated immediately. Unfortunately, people at risk for developing closed-angle glaucoma often have few or no symptoms before the attack. People at risk for closed-angle glaucoma should avoid over-the-counter decongestants and other medications where the packaging states not to use these products if you have glaucoma. These products are usually safe to use once your narrow angle has been treated with laser iridotomy. Always ask your ophthalmologist if it is safe for you to use products with this warning.
- Congenital glaucoma
Congenital glaucoma is a rare type of glaucoma that develops in infants and young children and can be inherited. While less common than the other types of glaucoma, this condition can be devastating, often resulting in blindness if not diagnosed and treated early. - Secondary glaucoma
Secondary glaucoma is glaucoma that results from another eye condition or disease. For example, someone who has had an eye injury, someone who is on long-term steroid therapy or someone who has a tumour may develop secondary glaucoma. The most common forms of secondary glaucoma are: pseudoexfoliative glaucoma, pigmentary glaucoma, and neo vascular glaucoma. - Glaucoma suspect
Some people have normal eye pressure but their optic nerve or visual field looks suspicious for glaucoma. These people must be watched carefully because some eventually develop definite glaucoma and need treatment. - Open-angle glaucoma
Other people have an eye pressure that is higher than normal, but they do not have other signs of glaucoma, such as optic nerve damage or blank spots that show up in their peripheral (side) vision when tested. This condition is called ocular hypertension. Individuals with ocular hypertension are at higher risk for developing glaucoma compared to people with lower, or average, eye pressure. Just like people with glaucoma, people with ocular hypertension need to be closely monitored by an ophthalmologist to ensure they receive appropriate treatment.
Glaucoma can often be caused by another eye condition or disease. This is known as secondary glaucoma. For example, someone who has a tumour or people undergoing long-term steroid therapy may develop secondary glaucoma. Other causes of secondary glaucoma include:- Eye injury
- Inflammation of the eye
- Abnormal blood vessel formation from diabetes or retinal blood vessel blockage
- Use of steroid-containing medications (pills, eye drops, sprays)
- Pigment dispersion, where tiny fragments or granules from the iris (the coloured part of the eye) can circulate in the aqueous humor (the fluid within the front portion of the eye) and block the trabecular meshwork, the tiny drain for the eye’s aqueous humor.
- People with a higher risk of developing glaucoma include people who:
- Are over age 40;
- Have family members with glaucoma;
- Are of African or Hispanic heritage;
- Are of Asian heritage (Asians are at increased risk of angle closure glaucoma and Japanese are at increased risk of low tension glaucoma);
- Have high eye pressure;
- Are farsighted or near-sighted;
- Have had an eye injury;
- Have corneas that are thin in the centre; or
- Have diabetes, migraines, high blood pressure, poor blood circulation or other health problems affecting the whole body.
If you have received a glaucoma diagnosis from your Eye M.D., your doctor will talk about possible treatment options, such as glaucoma eye drops and/or glaucoma surgery.
One of the problems with glaucoma, especially open-angle glaucoma, is that there are typically no symptoms in the early stages. Many people who have the disease do not know they have it. This is why it is important, especially as you get older, to have regular medical eye exams by an Eye M.D.
Your ophthalmologist will do the following tests and exams during a comprehensive glaucoma evaluation:
- Measure the pressure in your eye (tonometry)
Your doctor measures your eye pressure using tonometry. (See photo above) Testing your eye pressure is an important part of a glaucoma evaluation. A high pressure reading is often the first sign that you have glaucoma. During this test, your eye is numbed with eye drops. Your doctor uses an instrument called a tonometer to measure eye pressure. The instrument measures how your cornea resists pressure. Normal eye pressure generally ranges between 10 and 21 mmHg. However, people with normal-tension glaucoma can have damage to their optic nerve and visual field loss even though their eye pressure remains consistently lower than 21 mmHg. - Inspect your eye’s drainage angle (gonioscopy)
Gonioscopy allows your ophthalmologist to get a clear look at the drainage angle to determine the type of glaucoma you may have. Your ophthalmologist is not able to see your eye’s drainage angle by looking at the front of your eye. However, by using a mirrored lens, he or she can examine the drainage angle to determine if you have open-angle glaucoma (where the drainage angle is not working efficiently enough), closed-angle glaucoma (where the drainage angle is at least partially blocked), or a dangerously narrow angle (where the iris is so close to the eye’s drain that the iris could block it). - Ophthalmoscopy
Your ophthalmologist inspects your optic nerve for signs of damage using an ophthalmoscope, an instrument that magnifies the interior of the eye. Your pupils will be dilated (enlarged) with eye drops to allow your doctor a better view of your optic nerve.
A normal optic nerve is made up of more than one million tiny nerve fibers. As glaucoma damages the optic nerve, it causes the death of some of these nerve fibers. As a result, the appearance of the optic nerve changes. This is referred to as cupping. As the cupping increases, blank spots begin to develop in your field of vision.
Test your side, or peripheral, vision (visual field test)
The visual field test will check for blank spots in your vision. The results of the test show your ophthalmologist if and where blank spots appear in your field of vision — including spots you may not even notice.
The test is performed using a bowl-shaped instrument called a perimeter. When taking the test, a patch is temporarily placed on one of your eyes so that only one eye is tested at a time. You will be seated and asked to look straight ahead at a target. The computer makes a noise and random points of light will flash around the bowl-shaped perimeter, and you will be asked to press a button whenever you see a light with your side vision. You should not turn your eyes to look for the lights. Not every noise is followed by a flash of light. Visual field testing is usually performed every 6 to 12 months to monitor for change.
Measure the thickness of your cornea — the clear window at the front of the eye (pachymetry)
Because the thickness of the cornea can affect eye pressure readings, pachymetry is used to measure corneal thickness. A probe called a pachymeter is gently placed on the cornea to measure its thickness. A very thin cornea may increase your risk of glaucoma.
Glaucoma damage is permanent—it cannot be reversed. But medicine and surgery help to stop further damage. To treat glaucoma, your ophthalmologist may use medicated eye drops. These medications lower your eye pressure in one of two ways — either by reducing the amount of fluid created in the eye or by helping this fluid flow out of the eye through the drainage angle. These eye drops must be taken every day. Just like any other medication, it is important to take your eye drops regularly as prescribed by your ophthalmologist.
Once you are taking medications for glaucoma, your ophthalmologist will want to see you regularly. You can expect to visit your ophthalmologist about every 3–6 months. However, this can vary depending on your treatment needs.
Glaucoma medications can help you keep your vision, but they may also produce side effects. Some eye drops may cause:
- a stinging or itching sensation;
- red eyes or red skin around the eyes;
- changes in your pulse and heartbeat;
- changes in your energy level;
- changes in breathing (especially if you have;
- asthma or breathing problems);
- dry mouth;
- blurred vision;
- eyelash growth; or,
- Change in your eye colour, the skin around your eyes or eyelid appearance.
If you have glaucoma, it is important to tell your ophthalmologist about your other medical conditions and all other medications you currently take. Bring a list of your medications with you to your eye appointment. Also tell your primary care doctor and any other doctors caring for you what glaucoma medication you take.
In some patients with glaucoma, surgery is recommended. Glaucoma surgery improves the flow of fluid out of the eye, resulting in lower eye pressure.
Diabetes can cause vision in your eyes to change. If your blood sugar levels change quickly, it can affect the shape of your eye’s lens, causing blurry vision, which goes back to normal after your blood sugar stabilizes. There is also a link between diabetes and cataracts. Permanent blurring of vision due to cataracts can also result from changes to the lens due to excess blood sugar. Cataract surgery may be necessary to remove lenses that are clouded by the effects of diabetes and replace them with clear intraocular lenses to restore clear vision. Maintaining good control of your blood sugar helps reduce episodes of temporary blurred vision and prevent the permanent clouding of the lens that would require surgery to correct.
Diabetes is a disease that affects the body’s ability to produce or use insulin effectively to control blood sugar (glucose) levels. Although glucose is an important source of energy for the body’s cells, too much glucose in the blood for a long time can cause damage in many parts of the body, including the heart, kidneys, blood vessels and the small blood vessels in the eyes. When the blood vessels in the eye’s retina (the light sensitive tissue lining the back of the eye) swell, leak or close off completely — or if abnormal new blood vessels grow on the surface of the retina — it is called diabetic retinopathy.
Age-related macular degeneration (AMD) is a deterioration or breakdown of the eye's macula. The macula is a small area in the retina — the light-sensitive tissue lining the back of the eye. The macula is the part of the retina that is responsible for your central vision, allowing you to see fine details clearly.
In its earliest stages, people may not be aware they have macular degeneration until they notice slight changes in their vision or until it is detected during an eye exam. People who are at risk for macular degeneration should have regular eye exams to test for macular degeneration and, if diagnosed, begin treatment if appropriate.
Dry macular degeneration signs and symptoms
- Blurry distance and/or reading vision
- Need for increasingly bright light to see up close
- Colours appear less vivid or bright
- Hazy vision
- Difficulty seeing when going from bright light to low light (such as entering a dimly lit room from the bright outdoors)
- Trouble or inability to recognize people's faces
- Blank or blurry spot in your central vision
Dry macular degeneration can affect one or both eyes. You may not notice vision changes if only one eye is affected, as your unaffected eye will compensate for vision loss in the other eye.
Wet macular degeneration symptoms usually appear and get worse fairly quickly. Wet macular degeneration signs and symptoms:
- Distorted vision — straight lines will appear bent, crooked or irregular
- Dark grey spots or blank spots in your vision
- Loss of central vision
- Size of objects may appear different for each eye
- Colours lose their brightness; colours do not look the same for each eye
Recently much new information on macular degeneration has been discovered. Genetic changes appear to be responsible for approximately half the reason for individuals getting macular degeneration. Additionally, there are other risk factors for developing the disease. Many older people develop macular degeneration as part of the body's natural aging process. One large study found that the risk of getting macular degeneration jumps from about 2 percent of middle-aged people in their 50s to nearly 30 percent in people over age 75.
Oxidative stress and macular degeneration
Our bodies constantly react with the oxygen in our environment. Over our lifetimes, as a result of this activity, our bodies produce tiny molecules called free radicals. These free radicals affect our cells, sometimes damaging them. This is called oxidative stress and is thought to play a major role in how macular degeneration develops. Approximately 1 in 3 Caucasians have genetic changes that make them more prone to damage from oxidative stress, which can lead to macular degeneration.
Macular degeneration in families
Heredity is another risk factor for macular degeneration. People who have a close family member with the disease have a greater chance of developing macular degeneration themselves.
Inflammation and macular degeneration
Some studies have shown that inflammation (swelling of the body’s tissues) may play a role in macular degeneration development. Inflammation is the way the body’s immune system fights off infection or other things it considers “invaders.” But an overactive immune system with its associated inflammation may be a risk factor for macular degeneration.
Smoking, high blood pressure and abnormal cholesterol and macular degeneration
Smoking and high blood pressure are associated with the wet form of macular degeneration. Research also suggests there may be a link between being obese and having early or intermediate-stage macular degeneration develop into the advanced (wet) form.
Another risk factor for developing macular degeneration may include having abnormal cholesterol levels or having high blood pressure (called hypertension).
Many people do not realize they have a macular problem until they notice they have blurred or distorted vision. Regular eye exams by an ophthalmologist may help to detect problems or early stages of macular degeneration before you are even aware of them.
Dry macular degeneration: detection with an ophthalmoscope
To check for macular degeneration, your eye doctor will dilate (widen) your pupils using eyedrops and examine your eyes with an ophthalmoscope, a device that allows him or her to see the retina and other areas at the back of the eye. If macular degeneration is detected, your doctor may have you use an Amsler grid to check for macular degeneration symptoms such as wavy, blurry or dark areas in your vision.
Wet macular degeneration: detection with fluorescein angiography and optical coherence tomography
If your ophthalmologist suspects you may have the wet form of macular degeneration, he or she will take special photographs of your eye with fluorescein angiography and optical coherence tomography (OCT). OCT scanning is a sophisticated and exact tool that detects abnormal blood vessels by creating a special picture of your macula.
During fluorescein angiography, a fluorescein dye is injected into a vein in your arm. The dye travels throughout the body, including your eyes. Photographs are taken of your eye as the dye passes through the retinal blood vessels. Abnormal areas will be highlighted by the dye, showing your doctor whether wet macular degeneration treatment is possible and, if so, where to treat the abnormal vessels.
Dry AMD and nutritional supplements
Unfortunately, at this time there is no single proven treatment for the dry form of macular degeneration. However, a large scientific study has shown that antioxidant vitamins and zinc may reduce the impact of macular degeneration in some people by slowing its progression toward more advanced stages.
The Age-Related Eye Disease Study 2 (AREDS2) showed that among people at high risk for developing late-stage, or wet, macular degeneration (such as those who have large amounts of drusen or who have significant vision loss in at least one eye), taking a dietary supplement of vitamin C, vitamin E, lutein and zeaxanthin, along with zinc, lowered the risk of macular degeneration progressing to advanced stages by at least 25 percent. The supplements did not appear to provide a benefit for people with minimal macular degeneration or people without evidence of the disease during the course of the study.
Following is the nutrient supplementation shown to be beneficial in lowering the risk of macular degeneration progressing to advanced stages:
- Vitamin C – 500 mg
- Vitamin E – 400 IU
- Lutein – 10 mg
- Zeaxanthin – 2 mg
- Zinc oxide – 80 mg
- Copper (as cupric oxide) – 2 mg (to prevent copper deficiency, which may be associated with taking high amounts of zinc)
Another large study in women showed a benefit from taking folic acid and vitamins B6 and B12. Other studies have shown that eating dark leafy greens, and yellow, orange and other colorful fruits and vegetables, rich in lutein and zeaxanthin, may reduce your risk for developing macular degeneration.
These vitamins and minerals are recommended in specific daily amounts in addition to a healthy, balanced diet. Some people may not wish to take large doses of antioxidants or zinc because of medical reasons.
It is very important to remember that vitamin supplements are not a cure for macular degeneration, nor will they give you back vision that you may have already lost from the disease. However, specific amounts of these supplements do play a key role in helping some people at high risk for developing advanced (wet) AMD to maintain their vision, or slow down the progression of the disease.
Talk with your ophthalmologist to find out if you are at risk for developing advanced macular degeneration, and to learn if supplements are recommended for you.
Wet macular degeneration treatment
Treating the wet form of macular degeneration may involve the use of anti-VEGF treatment, thermal laser treatment or photodynamic therapy (PDT). Treatment of wet macular degeneration generally reduces—but does not eliminate-- the risk of severe vision loss.
Anti-VEGF medication injection treatments for wet macular degeneration
A common way to treat wet macular degeneration targets a specific chemical in your body that causes abnormal blood vessels to grow under the retina. That chemical is called vascular endothelial growth factor, or VEGF. Several new drug treatments (called anti-VEGF drugs) have been developed for wet AMD that can block the trouble-causing VEGF. Blocking VEGF reduces the growth of abnormal blood vessels, slows their leakage, helps to slow vision loss, and in some cases improves vision.
Your ophthalmologist administers the anti-VEGF drug (such as Avastin, Lucentis, and Eylea) directly to your eye in an outpatient procedure. Before the procedure, your ophthalmologist will clean your eye to prevent infection and will use an anesthetic drop or injection of anesthetic with a very fine needle to numb your eye. You may receive multiple anti-VEGF injections over the course of many months. Repeat anti-VEGF treatments are often needed for continued benefit.
In some cases, your ophthalmologist may recommend combining anti-VEGF treatment with other therapies. The treatment that’s right for you will depend on the specific condition of your macular degeneration.
Laser treatment for wet macular degeneration
Although most cases of wet AMD are treated with medication, in some instances thermal laser therapy may be used. Laser treatment is usually done as an outpatient procedure in the doctor’s office or at the hospital.
The laser beam in this procedure is a high-energy, focused beam of light that produces a small burn when it hits the area of the retina to be treated. This destroys the abnormal blood vessels, preventing further leakage, bleeding and growth.
Following laser treatment, vision may be more blurred than before treatment, but often it will stabilize within a few weeks. A scar forms where the treatment occurred, creating a permanent blind spot that might be noticeable in your field of vision.
Usually the abnormal blood vessels are destroyed by laser treatment. However, it is likely that 50 percent of patients with wet macular degeneration who receive this laser procedure will need a re-treatment within three to five years. You may be instructed to use the Amsler grid daily to monitor your vision for signs of change.
Photodynamic therapy (PDT)
In some cases, a type of treatment for wet macular degeneration called photodynamic therapy, or PDT, may be an option. This therapy uses a combination of a light-activated drug called a photosensitizer and a special low-power, or cool, laser to treat wet macular degeneration right at the centre of the macula.
This procedure is done on an outpatient basis, usually in an ophthalmologist’s office. The photosensitive drug is injected into a vein in your arm, where it travels through the body, including the abnormal vessels behind the central macula. The low-power laser light is targeted directly on the abnormal vessels, activating the drug, which causes damage specifically to those unwanted blood vessels.
After PDT, the abnormal blood vessels may reopen, so multiple treatments may be required.
What happens when macular degeneration cannot be treated?
It is important to remember that only about 10 percent of all macular degeneration cases are exudative, or wet form, and about 75 percent of these cases cannot be treated. People with wet or dry macular degeneration symptoms who cannot be treated will not become blind, as they will still have peripheral, or side, vision.
If you have untreatable macular degeneration, you can make the most of your remaining vision by learning to “see again” with the vision you do have and with the help of special low-vision rehabilitation, devices and services. People with low vision can learn new strategies to accomplish daily activities. These skills, including mastering new techniques and devices, help people with advanced AMD regain their confidence and live independently despite loss of central vision.
While there is little that can be done to improve the eyesight of someone who has AMD, with early detection, the rate of vision loss can be slowed. The keys to slowing vision loss are to understand macular degeneration, monitor your symptoms and visit your ophthalmologist regularly to test your vision. Even with macular degeneration, you can still maintain an enjoyable lifestyle.
A pterygium is a triangular-shaped growth of fleshy tissue on the white of the eye that eventually extends over the cornea. This growth may remain small or grow large enough to interfere with vision.
Some pterygia may become red and swollen on occasion, and some may become large or thick, making you feel like you have something in your eye. If a pterygium is large enough, it can actually affect the shape of the cornea’s surface, leading to astigmatism.
It is not entirely clear what causes pterygia to develop. Ultraviolet (UV) light from the sun is believed to be a factor in the development of these growths. Other factors believed to cause pterygia are dry eye and environmental elements such as wind and dust.
With a pterygium, some people may have no symptoms other than the growth appearing. For others, especially those who have a pterygium that is growing, there can be redness, inflammation or both.
Other symptoms may include:
- Blurred vision
- Itching
- Burning
- Gritty feeling
- Feeling of having foreign material in your eye
Pterygia generally don’t require treatment until symptoms are severe enough. When pterygium become red and irritated, lubricating eye drops or ointments or possibly a mild steroid eye drop may be used to help reduce inflammation.
If these growths become large enough to threaten sight or cause persistent discomfort, they can be removed surgically by an Eye M.D. in an outpatient procedure. They are also sometimes removed for cosmetic reasons.
For milder pterygia, a topical anesthetic can be used before surgery to numb the eye's surface. Your eyelids will be kept open while the pterygium is surgically removed. After the procedure, which usually lasts no longer than half an hour depending on the type of surgery done to remove the pterygium, you likely will need to wear an eye patch for protection for a day or two. You should be able to return to work or normal activities the next day. Note that pterygium removal can cause astigmatism or worsen the condition in people who already have this refractive error.
A pinguecula is a yellowish patch or bump on the conjunctiva, near the cornea. It most often appears on the side of the eye closest to the nose. It is a change in the normal tissue that results in a deposit of protein, fat and/or calcium. It is similar to a callus on the skin.
A pinguecula usually has few symptoms, however, if it becomes irritated, you may feel as if you have something in your eye. In some cases, pingueculae become swollen and inflamed. Irritation and eye redness may occur, particularly if you are significantly exposed to sun, wind, dust or a very dry environment.
Pingueculae generally don’t require treatment until symptoms are severe enough. When pingueculae become red and irritated, lubricating eye drops or ointments or possibly a mild steroid eye drop may be used to help reduce inflammation.
Uveitis is inflammation of the uvea, which is made up of the iris, ciliary body and choroid. Together, these form the middle layer of the eye between the retina and the sclera (white of the eye).
The specific cause of uveitis often remains unknown. In some cases, however, it can be associated with other disease or infection in the body. Such as:
- A virus, such as shingles, mumps or herpes simplex;
- Systemic inflammatory diseases;
- A result of injury to the eye; or
- Rarely, a fungus, such as histoplasmosis or a parasite, such as toxoplasmosis.
Studies have shown that smoking contributes to the likelihood of developing uveitis.
Uveitis may develop suddenly with eye redness and pain, or with a painless blurring of your vision. In addition to red eye and eye pain, other symptoms of uveitis may include light sensitivity, blurred vision, decreased vision and floaters. There may also be a whitish area (called a hypopyon) obscuring the lower part of the iris.
A careful eye examination by an ophthalmologist is extremely important when symptoms occur. Inflammation inside the eye can permanently affect sight or even lead to blindness if it is not treated. Your ophthalmologist will examine the inside of your eye. He or she may order blood tests, skin tests or X-rays to help make the diagnosis. Since uveitis can be associated with disease in other parts of the body, your ophthalmologist will want to know about your overall health. He or she may want to consult with your primary care physician or other medical specialists. However, in approximately 40 to 60 percent of cases, no associated disease can be identified.
Uveitis is a serious eye condition that may scar the eye. It needs to be treated as soon as possible. Eye drops, especially corticosteroids and pupil dilators, can reduce inflammation and pain. For more severe inflammation, oral medication or injections may be necessary. If left untreated, uveitis may lead to:
- Glaucoma (increased pressure in the eye);
- Cataract (clouding of the eye's natural lens);
- Neovascularization (growth of new, abnormal blood vessels); or
- Damage to the retina, including retinal detachment, damage to the optic nerve or both.
These complications may also need treatment with eye drops, conventional surgery or laser surgery. If you have a "red eye" that does not clear up quickly, contact your ophthalmologist.
Only after careful examination can your ophthalmologist tell whether a retinal tear or early retinal detachment is present.
Some retinal detachments are found during a routine eye examination. That is why it is so important to have regular eye exams.