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Education Library
Diabetic Retinopathy
Diabetic retinopathy (reh-tin-AH-puh-thee) is an eye condition that affects the retina in some patients who have had diabetes for many years. The retina, which is the light-sensitive nerve tissue that lines the back of the eye, is vital for vision. There are two forms to this condition: background retinopathy (the milder form) and proliferative retinopathy. Background retinopathy generally progresses slowly, over years, and eventually causes some visual disturbance; sometimes it develops into the more serious proliferative stage. The exact cause of the background retinopathy or why it progresses to proliferative retinopathy is not known. However, it is related to the length of time the patient has had diabetes, and it is more common in insulin-dependent diabetes than in cases where the diabetes can be controlled with an appropriate diet and oral medications. Since there are usually no early warning symptoms, patients who have diabetes need to have a complete eye examination regularly, at least once a year.
The earliest changes are subtle and only slightly different from normal. Some of the retinal blood vessels gradually enlarge; some become irregular in size and develop some tiny weak spots (microaneurisms), which is the hallmark of this condition. They begin to leak exudates (fluid, fat, and protein) and blood. At first, vision may be normal or only slightly affected, depending on where the leaks are located. The condition varies over time, sometimes getting better for a while and then worse, but tending to slowly worsen. As it advances, some of the smaller retinal blood vessels gradually become obstructed, resulting in a patchy loss of retinal nourishment. In some patients this lead to the development of proliferative retinopathy.
New, abnormal blood vessels begin to grow (proliferate) over the surface of the retina and optic nerve, that transmits images from the eye to the brain. (Doctors feel that they form in an attempt to nourish the patches of "starving" retina.) Unfortunately, these blood vessels are unusually fragile, and frequently break and bleed. If they bleed into the vitreous (into the center of the eyeball), vision can become clouded from the blood. At first the blood is rapidly absorbed, so vision tends to clear in a few weeks. But eventually, with re-bleeding, vision may not clear so rapidly or even at all. As more new vessels grow, the risk for more bleeding increases. Scars form and may tug on or even tear the retina, which can lead to a retinal detachment. All of these developments have the potential for leading to blindness.
In its early stages, background retinopathy does not cause any symptoms. Later, it can produce blurring of vision (from retinal leakage and swelling) that glasses cannot help. The early stages of proliferative retinopathy may also produce no visual symptoms; but later, bleeding can cause a sudden appearance of floaters, blurring, or even almost total loss of vision. Neither type, on its own, is likely to cause pain, but the proliferative form is sometimes associated with other eye problems that can cause eye pain.
For background retinopathy or even for minimal proliferative retinopathy, no treatment may be needed other than keeping your diabetes under good control. If the condition is more serious and is threatening to the vision, laser treatment may be recommended. Laser beams may be used for "focal treatment," to stop discrete retinal leakages, or for PRP (pan-retinal photocoagulation) - to create hundreds of tiny burns in the retina that reduce retinal swelling and congestion and the number of dangerous, abnormally proliferating blood vessels, thus reducing the risk of internal bleeding. More than one series of laser treatments may be needed, but all can be done on an outpatient basis and are usually painless.
Laser treatment may not help severe cases and sometimes lasers cannot be used at all, such as when the abnormal blood vessels, scars, and blood are too dense to let the laser beam shine through to the retina. Then, a major eye operation called vitrectomy may be suggested, to attempt removal of the scars and cloudy or bloody tissue. If this procedure is successful in clearing up the cloudy material inside the eyeball, laser treatment may then become possible.
Diabetic retinopathy is one of the major causes of defective vision and blindness in our country today. Although it is not totally preventable, its course may be made far less severe by diagnosing any eye problems early and then keeping a close watch for progression so that early treatment can be instituted when necessary. Patients with diabetes, should make sure you have a thorough eye exam at least every year (more frequently in advanced cases), and should always take the best possible care and control of the diabetes.
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Pink Eye
At one time or another, nearly everyone has had "pink eye," or conjunctivitis (kon-junk-tih-VI-tiss). The word conjunctivitis means "inflammation of the conjunctiva" (kon-junk-TI-vuh). The conjunctiva is the thin membrane that covers the white part of the eye (sclera) and the undersides of the eyelids. "Inflammation" means that this membrane is red, irritated or swollen.
Conjunctivitis is not a disease, but simply a reaction to something that is irritating the eye. Usually, but not always, it results from a viral or bacterial infection, but it can also be caused by allergy, irritants such as air pollution, smoke or noxious fumes, or minor trauma as from contact lenses, a scratch, or even a loose eyelash.
Healthy conjunctiva is transparent. It only looks white because the sclera under it is white. (On the undersides of the lids it looks pink because the tissues under it are pink.) Buried within the conjunctiva are many tiny blood vessels that normally don't show. When there is a conjunctival inflammation or irritation, the blood flow to these vessels is increased, engorging them and making them visible against the white background - thus the term pink eye. The reddish color is almost never due to actual bleeding.
Sometimes yes, sometimes no. It depends on what is causing it. Infectious conjunctivitis (caused by bacteria or viruses) can be contagious; but if the cause is an allergy or irritant, it is not. If there's any doubt, it is a good idea to assume it's contagious. That means not touching the non-infected eye after rubbing the pink eye, washing your hands after touching the eye or lids, and disposing of tissues used to wipe the eye.
Most causes of conjunctivitis are not serious and tend to clear up on their own. Some resolve after a few days, but viral infections may last several weeks and an allergic reaction may go on for months. Do not use any medication that contains corticosteroids (steroids for short), because if there is an infection, they can make it worse. Used without supervision, steroids can also lead to serious eye problems, such as glaucoma, cataract, or even blindness.
If the eye redness and irritation come on when the patient or the patient's family member has or has recently had an upper respiratory infection (cold, fever, runny nose), the culprit is likely to be the same "bug." If it's a virus, treatment will not usually be helpful. But for a bacterial infection, which often causes a gooey or pus-like discharge or a crusty mattering on the lids, an antibiotic eyedrop or ointment may be prescribed.
If both eyes are red, an allergy or atmospheric irritant may be the cause. Be alert to this possibility and try to be able to identify and avoid the offending substance. A seasonal allergy is likely if the eyes get red and itchy around the same time each year. Medication may be prescribed to relieve the symptoms. Contact lens wearers may develop conjunctival irritation and redness that doesn't clear up in several hours after removing the lenses, it could indicate that they are causing a problem that requires treatment.
Sudden, profuse tearing with lids that tend to want to close suggests that there is something in the eye or that the eye has been scratched or has a corneal infection. If these symptoms don't subside within a few hours, the eye should be examined. The same holds true if a child comes running in from outdoors with a red, tearing eye. This almost certainly means that the eye has been scratched or that there is a foreign body in it.
Conjunctivitis can occur in association with certain systemic diseases. And sometimes a red eye is not conjunctivitis at all, but a sign of a corneal problem or an internal eye condition that needs prompt medical attention. This includes iritis, uveitis (inflammations deep within the eye), and one uncommon type of glaucoma.
Do not ignore a persistently red eye in the hope that it will go away. If the symptoms are irritating and last for more than a few days, or especially if the eye is painful or if there is a lot of discharge, the problem may not be trivial. It is always better to be safe and have the eye examined.
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Convergence Insufficiency
Convergence insufficiency is a binocular vision condition where the two eyes fail to turn inwards enough when looking at near objects. The condition often leads to eyestrain and/or headaches when the patient tries to read or work at near for more than a few minutes. Other symptoms can include blurry vision or double vision that comes and goes especially as one becomes more fatigued. Any age can be affected by this condition.
Treatment for convergence insufficiency can include:
Pencil Pushups - This involves holding a pen or pencil at arm's length and focussing on the tip of the pen while slowly bringing the pen in towards the eyes. The pen is brought as close as possible until one sees the tip of the pen split into two or become very blurry. Sometimes at this endpoint, one can sense one of the eyes turning out. At this point, the pen is slowly pushed back while the individual concentrates on getting the two pen tips back into one and clear focus. The pen is slowly pushed away further until reaching arm's length. This is one pencil pushup. Thirty pencil pushups per day are performed daily for a few weeks. The pencil pushups should be split up as 3 groups of 10 pushups per day. Usually some improvement will be noticed after two weeks at which time 30 pushups/week may be sufficient to maintain better binocular vision. If one stops the pencil pushups, the eyes are likely to gradually return to their previous state.
Prism - A special lens called a prism can be incorporated into the reading prescription that "bends" the light in so that some of the convergence strain is taken off the eyes when reading and working up close. Prism is usually combined with pencil pushups to get the maximum effect and to prevent the eyes from becoming too dependent on the prism to do most of the work.
Further Convergence Treatment - Some optometrists specialize in treating binocular vision disorders. Presently this office does not specialize in BV therapy but if necessary may refer you to another optometrist in the area who does. so) of vision loss in your other eye. Permanent loss may be prevented by quick action.
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Dry Eye
Most people have enough tears to keep their eyes properly moistened and lubricated. Keratitis sicca, the medical term for dry eye (it actually means "dry cornea") is a condition in which there is not enough moisture in the eyes. Dry eye is more common in women than in men, and in middle age and the elderly than in younger people. The most likely cause of dry eyes is that there are not enough tears produced or that for some reason the eyelids do not close well, especially when during sleep. Dry eye is often related to other medical conditions, such as arthritis, or Sjogren's (show-grenz) syndrome, in which many of the body's other normally moist membranes (such as those in the mouth and nose) also lack moisture. Less commonly, it is associated with severe inflammatory mucous membrane diseases (such as pemphigoid).
The dryness usually leads to a constant burning or foreign body sensation. Eyes may be sensitive to light, and red and bloodshot a good deal of the time. These symptoms tend to be worse in dry climates, in dry and windy weather, and late in the day. Using a hair dryer may affect the eyes, as will dryness in air-conditioned and heated rooms, especially drafts, air flow from vents, or the dehumidified cabin of an airplane. Dryness of other mucus membranes, such as in the mouth and nose may occure as well as eye and eyelid infections. Many patients complain of "watery" or tearing eyes and are surprised to learn that their problem is really dryness. What happens is that as the moisture decreases, the amount of mucus increases and makes the eyes feel as if they are watering. The increased mucus may also blur vision.
Diagnosis of dry eye is confirmed by a Schirmer Test, in which a narrow strip of filter paper is placed in the corner of each eye for a few minutes and then the amount of moisture in the paper is measured.
Because there is no permanent cure, the goal of treatment is to add sufficient moisture to the eyes to relieve the symptoms. In most cases, this simply involves using artificial tears eye-drops several times a day, or even every hour if necessary. A non-medicated, lubricating ointment placed in the eyes at bedtime may relieve the dryness usually felt upon awakening. If symptoms persist, small "pellets" of concentrated artificial tears may be tucked under the lower eyelid once a day. If the dryness is caused by poor closure of the eyelids with sleep, a small piece of tape (hypo-allergenic paper tape is best) may be used to hold them closed. Soft contact lenses can sometimes relieve the symptoms, possibly because of their water-holding properties. However, some patients find that contacts seem to make matters worse. If none of these measures helps, it may be necessary to close the puncta (tiny openings in the eyelids that drain tears into the tear ducts and nose), to prevent losing what little moisture is left. The procedure may involve heat cautery, plastic plugs, or suture. Afterward, there may still be a need to continue using the eyedrops, ointments, or pellets. Try to avoid dry environments and use artificial tears or other moisturizing eyedrops as often as needed. Always carry the drops with you. If, at any time, the eye membranes feel as if they have become infected (the symptoms are increased redness and secretions), call the office for an immediate appointment.
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Macular Degeneration
Deterioration of the part of the eye called the macula causes a loss of the central part the visual field. Central vision, normally the sharpest, most useful vision, may become so impaired that objects viewed directly may seem blotted out, smudged, or shrouded in a dark haze. Because the condition tends to appear later in life, it is also called age-related macular degeneration, or AMD. AMD is the leading cause of poor vision in people over 60, though it can also occur at younger ages. Fortunately, peripheral vision remains normal, so even severe macular degeneration does not lead to total blindness.
The macula is the centermost part of the retina, the light-sensitive membrane of nerve tissue that lines the back of the eye. The retina is the "screen" upon which images are focused by the optical parts of the eye (cornea and lens). Although it's no larger than a pinhead, the macula contains the visual cells needed for sharp vision and for seeing straight ahead. If those cells are damaged, it becomes difficult or impossible to see fine detail and read small print. Scientists have not yet learned why a macula that has functioned normally for many decades begins to degenerate. Heredity is likely to play a role. Long-term exposure to bright sunlight may be involved. It is also possible that tissue changes that normally accompany aging somehow interfere with the macula's getting enough oxygen and nourishment. Recent studies have found a higher risk of AMD among smokers and former smokers. Other studies have found a relationship between a high intake of saturated fat and AMD. None of these studies, however, is conclusive. People who develop AMD are typically in good health. The condition does not appear to be caused by arteriosclerosis, high blood pressure or diabetes, or by drinking alcoholic beverages. It is not caused by using the eyes too much.
There are two major types of AMD, called dry and wet. Most patients have the dry type, which tends to develop slowly as the tissue beneath the macula gradually deteriorates. The wet type occurs when these tissue changes are accompanied by the formation of tiny abnormal blood vessels under the retina, called subretinal neovascular membranes, and these start to leak fluid or bleed. The lost visual sharpness is caused by fluid that has leaked under the macula and lifted it out of position. With either type, small deposits called drusen may build up under the macula. Though drusen may be a normal and harmless sign of getting older, they also may be a sign that degenerative macular changes are starting to develop. The typical first symptom (either type) is a blurring of vision in one or both eyes. A new prescription is not likely to improve vision because the problem is not with the optical parts of the eye. As time goes on, a hazy or dark zone in the center of objects may appear. And colors may begin to look different or lose richness. With the wet type especially, vision may become distorted and "wavy," so that straight lines, such as the edges of doors and windows, look bent or crooked. Any of the symptoms may be gradual or sudden, but the more abrupt changes are more likely to occur with the wet type.
Vision will be checked and a refraction test for glasses along with a complete eye exam. Pupils will be dilated (enlarged) with eye drops so that the inside of the eyes can be evaluated with an ophthalmoscope. A special type of observation lens or contact lens may be used on each eye to allow the retina and macula to be examined under high magnification with a slit-lamp microscope. Photographs may be taken of the retina. Pictures are useful in determining the extent of the problem and in evaluating its progression. A test called fluorescein angiography may be done in which, an orange-colored dye will be injected into an arm vein and a rapid series of retinal photographs taken as the dye travels through the eye's blood vessels. By identifying the position and extent of any abnormal blood vessels and any leakages, the angiogram provides important guidance for treatment.
So far, there are no medications for treating AMD. Dietary supplements (antioxidants, vitamins and minerals) have been suggested as a way to slow the degeneration, but scientific evidence for their effectiveness is inconclusive. Some studies show beneficial results, other don't. Long-term research is being conducted to help clarify whether supplements are effective. In the meantime, it seems prudent to take a regular vitamin-mineral supplement for whatever potential help it might offer. Sometimes, in the early stages of the wet type of AMD, a laser can be used to seal the leaks or to destroy the abnormal blood vessels under the macula. Laser surgery does not help the dry type of AMD. What is hoped for is that laser treatment will help stabilize or even improve vision. The use of a laser involves some risk because a laser can destroy normal neighboring tissue as well as abnormal tissue. So the surgery will be recommended only if the risk is small and there is a reasonable chance for success. It will not be attempted if the degeneration is too extensive, too advanced, or in too critical a location. Laser surgery seems to be most helpful and least risky when the angiogram shows leaks that are not too near the center of the macula.
AMD usually comes on gradually or in small spurts over many months and then its progress slows down or stops. Eventually, both eyes are likely to be affected, though the degeneration in one eye may precede the other, sometimes by years. There is also the possibility that new "wet" changes will occur later, even after successful treatment, or they can develop in someone who originally had the dry type. Sometimes the degenerative process stops before vision is reduced very much. Unfortunately, that does not happen often enough. In most cases, vision continues to decrease to the point that reading is hampered, and driving a car is no longer safe. If vision in both eyes drops to a level that cannot be improved with eyeglasses to better than 20/200, the term "legal blindness" is used. This is merely a legal definition used for determining eligibility for certain social services (and an extra income tax exemption). Remember, even if the degeneration is severe, side vision will remain normal. Some patients even surprise everyone by being able to see and pick up small objects from the floor.
In addition to having regular eye exams, take a few seconds every day to check vision with an Amsler grid, a small card printed with a pattern of crossing straight lines that form squares. The lines should look straight and solid. If any of them start looking wavy or having missing segments - which could indicate the beginning of wet changes that might be treatable - make an appointment with a doctor within the next few days. It is frightening to face the prospect of losing central vision. But there are new ways to use the sight left to the best advantage. Most people quickly learn how to use their peripheral vision more effectively, which includes learning to look slightly off-center. A low vision specialist can be a great help. This professional can work with you to select special eyeglasses and magnification devices that could allow you to see better in certain situations. Non-optical aids, such as large-type books and magazines, large press-on numbers for your appliances, and even talking clocks can be a great help. Consider joining a support group. Some people find it comforting to talk to others who share similar problems and exchange helpful ideas with them or seeking professional psychological support. Always keep in mind that using your eyes will never harm them.
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Floaters
Floaters are translucent specks that seem to float about in the field of vision. Most people have some floaters normally, but they usually do not notice them until they become numerous or more prominent. Looking like cobwebs or squiggly lines or floating bugs, floaters become apparent when looking at something evenly bright, such as white paper or a blue sky, and are more evident with eye movement. They are especially noticeable on looking through an optical instrument, such as a microscope or binoculars. They are more common and seem to be more annoying to people who are nearsighted or who have had a cataract operation.
Much of the interior of the human eyeball is filled with vitreous gel (also called the vitreous), a clear, thick substance that helps in maintaining the eye's round shape. Light passes through the vitreous (after being focused by the cornea and lens) to reach the retina, where images are formed. Any bits of tissue in the vitreous cast shadows onto the retina, and shadows are seen as something "floating" in your field of vision. Before birth, there is a large blood vessel in the vitreous, but by birth the vessel is no longer required and it disintegrates - but not completely. The broken-up particles remain for life and float around. These are the floaters that everyone has. Other occurrences can add more floaters. As eyes age, the vitreous may become stringy, and the strands cast tiny shadows on the retina. Bits of debris from other tissues in the eye may fall into the vitreous. Floaters may come from old or new bleeding within the eye. They may be the result of a disease that causes opaque deposits in the vitreous or of an ocular inflammation that causes cellular debris, or they may be a residual from an old injury.
In most cases floaters are simply an annoyance. An eye examination will usually reveal if there's something serious that needs medical attention. The sudden appearance of new floaters, sometimes accompanied by flashes of light in the peripheral (side) vision, can be a sign that a vitreous detachment has occurred, a frequent consequence of aging that is not usually serious. On rare occasions, however, these symptoms can be a danger sign that a retinal tear has occurred. The only way to diagnose the actual cause of the problem is by a complete eye examination, followed by another one a few weeks later.
Whenever floaters interfere with vision, shift them out of from the line of sight by moving the eyes around quickly, side-to-side or up and down. The only way to get floaters out of the vitreous gel is by surgical removal, and since they are rarely more than a nuisance, the benefit of surgery would not warrant the risks. Surgery might be considered necessary only if the cells and debris are extremely dense and numerous, enough to interfere with useful vision, but this is very rare.
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Cataracts
A cataract is any clouding or opacity in the crystalline lens - the transparent lens inside the eye. It is not a tumor or growth of skin over the eye. Most cataracts develop as part of the aging process, from a change in the chemical composition of the lens. Some scientists feel that prolonged exposure (over years) to sunlight can damage the lens and plays a role in cataract development. Cataracts can also be caused by eye injuries, certain eye diseases and body conditions, hereditary or birth defects, and some medications. They are not caused or made worse by using or "overusing" the eyes.
Some notice a gradual blurring or dimming of the vision. Haze or a "halo" can be seen around lights, especially at night, or have hazy or double (or multiple) vision. At first, the symptoms may occur only in dim light or when facing bright oncoming car headlights, making night driving difficult. Pain, headaches, and eye irritation are not usually symptoms of cataract. If the cataract is small, it may not disturb the vision or cause any symptoms at all. Even a large or dense cataract may not be noticed if the other eye is providing clear vision. Some are not aware of the blurred vision unless the uneffected eye is covered. Unless it is very dense, a cataract is not visible to the naked eye of an observer. No one can predict how fast a cataract will develop. Generally, the clouding of the lens is a slow, gradual process that takes amonths or even years. It is not known why some cataracts progress rapidly and others progress slowly.
Cataract surgery is one of the most effective and safest operations performed today. The high success rate is due to advances in microscope technique, high tech instruments, ultrafine needles and suture material, and use of intraocular lenses. Though rare, infection, bleeding, glaucoma, corneal problems, chronic intraocular inflammation, and retinal detachment are possible. Most of the complications, if they do occur, are usually temporary or can be treated successfully with medications; rarely, they require a second surgical procedure. There are several procedures for removing the cloudy lens. In each, a small incision is made in the front of the eye and an instrument is inserted into the eye to remove the lens. Your eye remains in its normal position during the operation. It is never removed from its socket. With the extracapsular method, the front part of the capsule is opened and the lens taken out, leaving the back part of the capsule in its normal position. The newest extracapsular techniques are referred to as "small incision" surgery. One of these involves phacoemulsification (FAKE-oh-ee-mull-sih-fuh-KAY-shun), in which a needle-like ultrasonic instrument is introduced into the eye. It delivers high-frequency sound waves to break up the opaque lens into tiny fragments that are then gently suctioned out through the instrument's hollow tubing.
Cataract surgery removes the crystalline lens, a major focusing element of the eye. Without a lens, vision would be very poor. Good vision, however, depends on many factors, such as how vision is corrected after surgery, as well vision before surgery and the eye's overall condition. When Intraocular lens (IOL) are implanted during surgery, focusing power and vision will be restored. Images normal in size and shape, and depth perception and side vision will be very natural. Usually eyeglass correction for reading and for sharp distance vision is required. It may takes several weeks before the operated eye is fully healed and vision is stabilized. If there is a special need for very sharp vision before then, eyeglasses can be prescribed early but, they may need to be changed soon afterward.
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Myopia, Hyperopia, Astigmatism and Presbyopia
When the eye's optical power and length do not match perfectly, vision will not be in focus. Mypoic (nearsighted) vision is when distance vision is blurry, but close-up objects are clear. High myope (very nearsighted) if when objectshave to hold objects very close to your eyes to see them clearly.
If you are farsighted (hyperopic), you can see clearly in the distance but only by expending more focusing effort than normal, and even more effort for up close. You may not even be aware of the added effort, but over a period of time it can cause eyestrain and headaches. Farsightedness may not become a problem until you get older. (How much older depends on the amount of farsightedness.) Actual difficulty with focusing up close, which becomes evident in everyone by age 45 or so, will probably be noticeable earlier, perhaps when you are about 35, or even sooner if you have a very large hyperopic error.
Having a refractive error does not mean that your eyes are "bad" or "weak." Just as some people are tall and others are short, some have small hands and others have large feet, those having long eyeballs tend to be nearsighted and those with short eyeballs, farsighted. No one can tell by looking at you if your eyeballs are long or short.
Astigmatism is a specific type of blurred vision usually caused by an uneven (non-spherical) contour of the cornea, the clear front surface of the eye that overlies the colored iris. The cornea is important for focusing, so any shape irregularity can significantly affect your vision. Actually, just about everyone has some astigmatism from birth. It needs correction only if your effort to obtain clear vision creates eyestrain or headaches. Astigmatism is almost always correctable with prescription glasses or with some types of contact lenses.
Presbyopia is an age-related decrease in ability to focus up close, caused by a loss in flexibility of the natural lens within the eye. Glasses are needed to correct for this particular refractive error.
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Bell's Palsy
The muscles in your face are controlled by the facial nerve. When the facial nerve becomes inflamed, as from a virus infection, it loses the ability to control the facial muscles. This is the most common cause of a Bell's palsy. Many other conditions can affect your facial nerve. The more serious ones include tumors of the salivary gland, problems in the inner ear, infections, and various neurological conditions and tumors, but all of these are rare. Facial appearance and expression depend on the normal action of the muscles in your face. Sudden paralysis (palsy) of the facial muscles - called Bell's palsy - is a fairly common condition. If the loss is only partial, it is called a paresis instead of a palsy, but the problem is essentially the same. A side of the face will feel "funny" or not move right. One eye will not blink normally - and the corner of the mouth sags on that side. Over the next few days the condition may worsen, and the affected eye may feel scratchy and teary, and vision on that side may be blurred. The lower lid may sag or droop and the skin on that side of the face may become numb.
Along with the problem of not being able to move the lips very well for talking and eating, loss in part or all of the ability to close or blink the eyelid on the affected side. For proper functioning, the eye requires a continuous flow of moisture over its surface. Each time you blink, the upper eyelid sweeps across the eye like a windshield wiper and spreads your tears smoothly over the cornea (the focusing surface of the eye). Without the ability to blink, the cornea dries out and its cells begin to die. If left dry for too long, a corneal ulcer may form, and if the ulcer should become infected, the result may be scarring or even perforation of the cornea, which can lead not only to loss of vision, but even to loss of the eye itself. Thus, in addition to the change in facial appearance, it is important to understand that eyesight is also very much endangered.
Bell's palsy often heals on its own over the next few weeks or months. Any treatment for the paralysis will depend on what has caused it. In the meantime, it is important to prevent corneal drying and ulceration. Use artificial tears eyedrops and/or a lubricating ointment in your eye frequently, as often as every 15 to 30 minutes if necessary. At bedtime, use liberal amounts of the ointment and spread it evenly by gently moving the eyelid around with your finger. This will help prevent damage to the cornea, which is most likely to occur while you are sleeping because you are unaware of any discomfort caused by the drying. If tears or ointment are inadequate to prevent corneal drying, you may need to tape the eyelids shut at night. If so, use a small piece of hypo-allergenic paper tape to hold the lids closed. You must be careful not to injure the cornea with the tape. You will be shown how to apply the tape properly.
If these simple measures do not protect the cornea sufficiently, or if the paralysis becomes permanent, more stringent measures will be required. Some patients are helped by having a "moisture chamber" placed over the eye, but the best treatment is minor surgery to attach the upper and lower eyelids together at each side, leaving a slit-like opening to look through. This procedure is called a tarsorrhaphy. Later, if the facial paralysis lessens or is corrected, the lids can be easily re-opened. In the interim, complete and adequate protection of the eyes from drying is essential and may require any or all of the treatment methods discussed above. Ignoring the problem or delay in treating it can cause serious scarring of the cornea and eventual loss of sight.
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Dyslexia
The ability to read, something that most of us take for granted, is really a very complex skill. A child needs to have a certain level of brain maturation in order to coordinate all the visual and perceptual tasks that reading requires. Some children simply need more time than average to learn how to read; others never seem to get the hang of it. Children with dyslexia, however, are not merely slow readers; they have a specific type of reading disability. Even when they see letters and words clearly, their brain is not able to process them in a way that permits reading. The problem may exist alone, or it may be part of a general learning disability. About 1 out of every 10 children is affected to some degree, though not every child has exactly the same perceptual stumbling block. Some transpose letters (T-A-C for C-A-T). Others see letters in the correct order but their brain does not connect them into words, or they have difficulty connecting words into meaningful sentences. Dyslexia is not related to intelligence. The fact is, most dyslexics have normal or above-normal intelligence and can understand material when it is read to them.
The interchanging of letters (and numbers) or inability to process them into words and sentences is thought to be associated with a "miswiring" of certain connections within the brain. The problem tends to run in families, so it probably has a genetic basis, though some cases may be related to mild brain damage, such as from a difficult birth or a viral infection. Some dyslexic youngsters merely have delayed maturation and may outgrow the problem. The diagnosis of dyslexia cannot be made by examining the eyes. Because of the normal association between reading and eyesight, many people tend to assume that dyslexia is caused by or related to an eye problem. But this is not so. A need for glasses or the presence of poor eye alignment or focusing might slow reading somewhat, but these common eye disorders do not cause the severe types of reading difficulties that dyslexic children have.
Many dyslexic children have a short attention span, are hyperactive and fidget a lot, but that does not mean that these signs are reliable indicators of dyslexia. The diagnosis is best made by a team of experienced professionals (which may include a pediatric neurologist and a reading educator), who test for the specific type of reading difficulty and can then tailor educational methods to fit that particular problem. With good teaching, most dyslexic children can be taught to read, though they are not likely to ever become "good" readers. The methods used will generally be different from those used to teach reading to other children. For example, children who cannot build words out of letter combinations by seeing them may learn to read by touching letters cut out of sandpaper. They can also develop other learning skills to take the place of reading.
Whenever a child's learning or reading skills are slow to develop, parents tend to blame themselves, thinking they must have done something wrong. This guilt, and the strong desire to make matters right for their child, can lead to unproven far-fetched or undocumented methods. Such as "visual training clinic" where children do hand-eye coordination exercises, run through mazes or use trampolines or balance boards. But there is no scientific evidence that these activities will have any effect on their reading ability. Wearing colored lenses, or placing colored plastic overlays on reading material, is thought by some to have a scientific basis, but more study is needed before it is known whether or not such techniques really help.
While it is understandable to want to try every possible means of helping, treatments that have not been proven to be effective only waste a lot of time and money. What's more important, they delay starting your child in an individualized educational program, which has a much better chance of success. Some dyslexic children seem to show slight improvement after even an unproven treatment. Experts feel that the apparent benefit in such cases does not come from the treatment itself but from the time and personal attention given the child, or possibly from maturing of parts of the brain that deal with reading ability. Parents must stay aware of the need to build up their child's ego and provide continuous emotional support. If you can help your child feel successful outside of school - perhaps in music, art, or sports - he or she may gain the confidence to set goals and work toward achieving them. In spite of their handicaps, some dyslexics have become artists, musicians, scientists and mathematicians, and some have been able to enter professional and technical careers. With desire and hard work, dyslexics can be very successful!
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Iritis
The iris is the part of the eye that may be blue, brown, gray, hazel or green. Its function is to change the size of the pupil (the round, black-looking opening in its center that allows light to enter the eye) by contracting or relaxing muscles that lie within it. Iritis is an inflammation of the iris. It can occur in one eye or, less commonly, in both. Iritis is a serious condition, so do not treat it casually or ignore it, hoping it will go away by itself. Sometimes there are no symptoms at all. Other times, an eye with iritis looks "bloodshot" and may be extremely uncomfortable in bright light. Sunlight or the glare of automobile headlights at night can even cause pain or aching in the eye or brow. The pain comes from the tightening of inflamed muscles as they constrict the pupil in bright light, and the red color comes from congestion of blood vessels on the outside surface of the eye, which is a reaction to the inflammation. There may also be some blurring of vision.
Although there are many possible causes, most of the time the exact one cannot be identified. Iritis can occur independently or in association with inflammations elsewhere in the body, such as in the joints (arthritis or spine spondylitis), teeth or sinuses, or bowels (colitis). Usually it is not due to an infection, is not contagious, and is not related to infectious "pink eye." If iritis is not treated promptly, there can be complications that threaten vision. These complications occur because the inflamed iris gets "sticky" and adheres to the lens, which lies directly behind it, or to the cornea, which is in front of it. The areas of stickiness, called synechiae, can be dangerous because they might block the normal channels for fluid flow within the eye and lead to secondary glaucoma, a serious condition that can lead to blindness. Other complications of iritis are cataract, retinal swelling, and other internal eye damage.
If the iritis is severe, the intraocular muscles must be rested and the pupil must be kept dilated (enlarged) with cycloplegic eyedrops. These help relieve much of the pain because they allow the iris and the other intraocular muscle (called the ciliary body) to rest by preventing their normal constriction, especially in bright light; the dilation also keeps the iris away from the lens and cornea so that synechiae and scarring are less likely to form. If synechiae are already present, the dilation may pull free those that are not firmly attached. Even though cycloplegic drops blur your vision, which can be annoying and make it difficult to see well enough to read or even drive a car, they are very important and should not be discontinued until told that it is safe to do so. Other treatment includes steroid eyedrops or oral anti-flammatory agents. If the iritis is severe and does not respond well to the medication, steroid injections may be given under the conjunctiva (membrane overlying the eyeball), or steroid pills, which must be taken exactly as directed to help reduce serious side effects. Medications may produce very rapid relief at first, but the complete control of an iritis attack tends to be a slow process. As the inflammation subsides, you will be given instructions for reducing the medications gradually. This is important. Stopping treatment suddenly could result in a flare-up of the attack.
An iritis attack may be completely cleared by treatment and never occur again, or it may recur in the same eye or in the other eye. A red eye even years later could indicate another attack. If at any time an attack may be starting, call for an appointment right away. Be sure to tell any other doctor that you have a history of iritis. Self-treatment is not wise. It is not a good idea to use eyedrops that have been in the medicine cabinet for a long time - they may have lost their potency or worse, they may have become contaminated with bacteria. Because of the possibility of side effects, never take steroids without medical supervision.
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Retinal Vein Occlusion
The sudden blockage (occlusion) of the blood vessel called the central retinal vein is a type of small stroke in the retina. The abrupt disturbance in the retina's blood circulation usually causes a rapid reduction in vision. Good vision requires a healthy, well-nourished retina, which depends on a steady stream of oxygen-rich blood - brought to it by arteries and carried away by veins. The central retinal vein (CRV) is the main blood vessel that drains "used" blood from the retina. When this vessel is blocked, the entire retinal bloodstream swells and backs up.
When this happens, fresh blood cannot enter the retina. And without the oxygen that is normally brought by the blood, the retina slowly starves and some retinal cells die. Hemorrages occur in the retina and reduced blood supply sets the stage for the possibility of even more damage to the retina. Months later, the starved retina sometimes starts to grow new blood vessels. The process is called neovascularization (neonew; vascular blood vessels). Though you might think that new blood vessels are just what the retina needs, these vessels are not normal. They are extremely fragile, bleed easily, and can lead to scarring of the clear tissues inside the eye. Any of these complications can further obscure the remaining vision.
The most usual cause is a blood clot that forms in the vein. That can happen whenever something slows down the normal flow of blood; for example, pressure on the vein from an overlying hardened artery (arteriosclerosis) can slow the flow of blood in the same way a fallen log tends to obstruct a stream. Increased fluid pressure within the eye (glaucoma) or an inflammation in the vein wall (vasculitis) can also slow blood flow. Or there may simply be an increased tendency for blood to clot (this is a rare complication in some women taking oral contraceptives and in certain medical conditions). Most causes of CRVO are related to aging changes and are more likely to occur in patients who have atherosclerosis, hypertension, diabetes, or glaucoma.
A complete eye examination will be performed, including a test of vision. The pressure inside the eyes will be checked with a painless test called tonometry. Depending on the type of tonometer used, there may be anesthetic eye drops. Pupils will be dilated (enlarged) with eye drops so the insides of both eyes can be studied. An ophthalmoscope and a slit lamp (clinical microscope) are instruments used for looking inside the eyes, and are especially useful for studying the retina and its blood supply.
Retinal photographs may be taken to determine the extent of the problem. An angiogram (photographs of blood vessels) may be made. For this test, a greenish-orange dye fluorescein) is injected into a vein in the arm and immediately followed by a series of retinal photographs that track the dye and time its flow as it travels through the eye's blood vessels. The angiogram also helps identify the site of the vein's blockage, the extent of damage to the capillaries (the smallest retinal blood vessels), and the presence of neovascularization. Because CRVO can be associated with several medical conditions that affect the rest of the body, you may be referred to an internist or family physician for a complete physical check-up after your eye examination.
If the occlusion has existed for only a few hours, it may be possible to slow or even reverse some of the retinal damage with eye drops or other medications. The purpose is to lower the pressure inside the eye and lessen the tendency for further blood clotting. If the occlusion lasts for more than a day or so, there is usually little that can be done to stop the damage or to speed normal healing. Eventually, the blocked vein may re-open on its own or nearby blood vessels (collaterals) may expand and redirect the flow of blood around the blockage site, but the vision that has been lost is not likely to return to normal.
If neovascularization develops later, a type of laser surgery called pan-retinal photocoagulation (PRP) can help reduce the number and severity of the abnormal blood vessels. In this procedure, many hundreds of tiny laser burns are made in the retina during a 15 to 30 minute operation. The treatment is generally painless and can be done on an outpatient basis. If the neovascularization does not subside sufficiently within a few weeks, additional laser treatments can be given. PRP is not likely to improve vision directly. It is designed to reduce the risks created by neovascularization, such as damage from internal bleeding or the development of hemorrhagic glaucoma, a much more serious condition than the common type of glaucoma that is sometimes a cause of CRVO. Occasionally the laser cannot be used at all, especially when there are opacities (dense blood or cataract) within the eye that block the laser beam from reaching the retina.
After a CRVO in an older patient, vision will seldom get very much better. Many eyes remain legally blind. Younger patients (under age 50) are more likely to recover some vision, even without treatment; but it may take many months, and even at best their eyesight will not be as good as it was before the occlusion occurred. Routine eye exams are important after a CRVO. What is being watched for are the development of potential late complications, especially neovascularization and glaucoma, or even a pending problem in the other eye.
Fortunately, complications of retinal vein occlusions are not common, and a CRVO is very unlikely to occur in your other eye. However, an immediate eye exam is important if you should notice any brief episodes of vision loss.
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