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Interacting with Visually Impaired Individuals Tax Benefits for Hiring the Visually Impaired 
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Home » About » News & Information » Leading Causes of Blindness Leading Causes of BlindnessDIABETIC RETINOPATHY  Diabetic Retinopathy, characterized by ruptures or breaks in the capillaries and blood vessels of the retina, is the new leading cause of blindness in the United States. It is a disorder in which small blood vessels nourishing the retina (back layer of the eye) weaken and break down or become blocked. The retina is essential to vision and is somewhat like the film of a camera—receiving an image to be "developed" in the brain. Its delicate network of light-sensitive nerves is normally supplied with oxygen and other nutrients by blood vessels that, due to diabetic retinopathy, begin to bulge out, leak fluid, bleed, grow abnormally or close down completely. Diabetic Retinopathy is one of the complications associated with the general circulatory problems developed by people with diabetes. The longer a person has diabetes, the greater the risk of retinopathy—more than 40 percent of those who have diabetes for more than 15 years or more have some degree of blood vessel damage. Of these, a smaller percentage develops the most serious consequence of the disease—severe visual impairment or total blindness. Early treatment of retinopathy often improves the potential for preserving sight. Every diabetic should receive regular care form a doctor and should also see an eye care specialist before any visual symptoms appear. An ophthalmic exam by a specialist should be repeated at least once a year for both adult and child diabetics. Pregnancy, high blood pressure and smoking can worsen this condition. What are the stages of Diabetic Retinopathy? In the early stages of diabetic retinopathy, blood vessels swell and sometimes bulge. The vessels may leak fluid, which can accumulate in the retina and distort vision. Although these fluid deposits may clear up on their own, they often leave fatty deposits that can also interfere with vision. Later, vessels may begin to bleed within the retina. In many cases, when the small blood vessels close down, new abnormal blood vessels may develop. These abnormal vessels are not able to provide nourishment to the retina. They can, however, penetrate the vitreous, the clear, jelly-like fluid filling the major portion of the eye's interior. These new vessels, which are very weak, can bleed into the vitreous, causing dark spots, cobweb-like strands or severe clouding in the field of vision. Sometimes, the formation of fibrous scar tissue can pull the retina away from its source of nutrition on the back of the eye. If the retina becomes detached or tears, the result can be serious loss of vision or even blindness. What treatment is available for Diabetic Retinopathy? The treatment for some forms of vision-threatening retinopathy is photocoagulation—the use of an intense beam of laser light to seal leaking or bleeding blood vessels. In this procedure, a laser light beam is carefully targeted to problem areas that have been pinpointed earlier with fluorescent dye. In advanced cases, photocoagulation is more extensive and can be used to repair torn retinas. Laser therapy can also control or prevent the abnormal growth of new, non-functional blood vessels. This form of treatment is not, however, appropriate for every case of diabetic retinopathy. Another recent treatment for advanced cases of diabetic retinopathy, in which abnormal vessel growth is severe and bleeding persists, is called vitrectomy. In this technique, a delicate instrument is used to remove the blood deposits and scar tissue strands within the vitreous fluid by suction. At the same time, through another channel of the instrument, a clear salt solution is injected to replace the vitreous. Medical scientists continue to work toward a better understanding and the management of diabetic retinopathy. In the meantime, early diagnosis and close observation by an eye care specialist are major objectives in the successful treatment of at-risk patients. It is important for the diabetic patient to be aware that dangerous changes in the retina often occur before vision is affected. CATARACTS  Cataracts, a leading cause of blindness among adults 45 years of age and older, are a clouding of the eye's lens. Because of this cloudiness, light rays do not easily pass through the lens to focus on the retina. As a result, things look foggy or cloudy. What are cataracts? Cataracts are a leading cause of blindness among adults in the United States. Although most prevalent among older persons, a cataract can occur in young people, and can sometimes be found in a baby's eyes at birth. A cataract is an opacity, or clouding, of the eye's lens that blocks the normal passage of light needed for vision. The lens of the eye is located behind the pupil and the colored iris, and is normally transparent. Its role is to help focus images to the brain. The underlying cause of cataract formation has not yet been determined, although it is known that a cataract is associated with chemical changes within the lens. Most often a cataract is related to the normal aging of a person—and the eye. Other factors that play a role are infection; hereditary influences and congenital events, such as German Measles in the mother; some medications, such as long-term steroid therapy; physical or chemical injury to the eye; and exposure to intense heat or radiation. Eye diseases and certain general diseases, including diabetes, are also associated with cataract development. What are the symptoms of cataracts? Cataract formation is generally not associated with "signals" such as pain, redness and tearing. The symptoms of a cataract all revolve around interference with vision: blurred vision, double vision, spots, ghost images, the impression of a "skim" over the eyes, problems with light, such as finding lights not bright enough for reading, or being "dazzled" by intense light. The need for frequent changes of eyeglass prescriptions—which may not help—is another symptom. As a cataract develops, it may be noticeable to other people as a milky or yellowish spot in the normally black pupil. When the area of clouding is small and away from the center of the lens, there may be little interference with vision, except for the annoyance of corresponding loss of detail in the visual image. If such a cataract progresses a great deal, however, or if the cataract began in the center of the lens, visual difficulty may be marked and may interfere with everyday activities. A cataract may develop rapidly over a period of a few months, or it may progress very slowly over a period of years. In other instances, it may progress to a point and stabilize resulting in visual difficulty that never reaches a point where an ophthalmologist will advise surgery. What treatments are available for cataracts? The only proven effective treatment of a cataract is surgery, and although it is a delicate procedure, it is one of the safest operations done today. Cataract surgery has been perfected to the point where success is attainted in more than 95 out of 100 cases. In less than five percent of cases, the surgery can be complicated by inflammation, bleeding, infection or retinal detachment. The determination of when and if surgery is advised will be made by the ophthalmologist and patient, in accordance with the patient's degree of vision loss, interference with normal life activities and other important factors. In cataract surgery, the clouded lens is removed. There are varying techniques for the surgical procedure itself; the ophthalmologist will select the method best suited to the patient, considering factors such as the degree of "ripeness" of the cataract, the age of the patient, the patient's general health, other ocular conditions and any other influences. Cataract removal can be done by cutting loose the lens capsule with a tiny surgical scalpel, breaking up the lens with an ultrasonic needle and extracting it with suction; or by contact with an intensely cold probe which sticks to the lens and lens capsule, allowing it to be lifted out in one step. Cataract surgery is like taking the lens out of a camera; and substitute lens power is needed so that the eye can focus images onto the retina, as a camera lens focuses images on film. Today a patient has three choices for a substitute lens: cataract eyeglasses (which at one time were the only option), contact lenses or an intra-ocular lens implant. Presently, a lens implant is used in the majority of cases. Not everyone, however, is a candidate for implants. People who are extremely nearsighted or who have certain eye diseases may not be able to have implants. Sometimes complications arising from an implanted lens can necessitate removal of the lens, but such problems are rare.  Glaucoma is often called "the sneak thief of sight." If left untreated, vision can be reduced to a narrow area known as tunnel vision and then, total blindness. What is glaucoma? Glaucoma is a leading cause of blindness among adults in the United States. It is estimated that one out of every seven blind persons is a victim of glaucoma. Practically all of these individuals had normal sight most of their lives, but sometime during their 40s, 50s or 60s they lost their sight. Glaucoma rarely strikes until after the age of 35, and sight cannot be restored. There are two principal types of glaucoma: acute and chronic. The acute type strikes suddenly, inflicting cloudy vision, often with severe pain in and around the eyes. The chronic type—which is more common—progresses slowly and painlessly, with symptoms that may appear intermittently. The eyeball is similar in size and shape to a ping-pong ball, but instead of air, a thick, jelly-like fluid fills most of the eyeball to give it shape. During the first stages of glaucoma, the pressure of this fluid in the front of the eyeball increases, although medical science has not established just why. The fluid in the rear of the eyeball—under increased pressure from the front—pushes against the retina, located at the back of the eyeball. The nerve cells and fibers of the retina are a major link in the process of seeing. It is this link that glaucoma attacks, by reducing the blood supply that nourishes the cells and fibers. At first, the increased fluid pressure damages only those retinal nerve cells and fibers responsible for peripheral vision. As a result, side vision is gradually destroyed. In the final stages, the pressure destroys the nerves that permit front and central vision, and all sight is then gone. What are the symptoms of glaucoma? The symptoms of the chronic type of glaucoma include:
Can blindness from glaucoma be prevented? If glaucoma is discovered early, medical treatment can halt its progress. However, sight destroyed by glaucoma cannot be restored. For each month that a glaucoma victim postpones treatment, he or she may permanently lose a small but priceless percentage of sight. The good news is that needless blindness can be prevented. Eye doctors have the equipment and knowledge to detect glaucoma and to start treatment. A person who is free of glaucoma at age 35 still may contract it at age 40. That is why the best defense against glaucoma is an eye exam at least every two years. Age-related macular degeneration, a degenerative disease that causes a small area of the eye tissue called the macula to deteriorate, usually occurs in persons who are over 50 years of age. Adaptive devices may be helpful in making good use of remaining vision. What is macular degeneration? Macular degeneration is a degenerative eye disease that causes atrophy, or deterioration, of a small area of the eye tissue in the center of the retina, called the macula. The macula is responsible for central vision, the sight used for tasks such as reading, driving, and watching television. Since side, or peripheral, vision is not affected, total blindness from macular degeneration almost never occurs. Who is at risk for developing macular degeneration? Since most cases of macular degeneration develop in people over 50 years old, it is often called age-related macular degeneration. A tendency to develop macular degeneration may be seen in some families because of genetic factors. How is macular degeneration detected? Ophthalmologists routinely screen for macular degeneration during regular eye examinations. During an exam, an ophthalmologist may observe changes that may be a sign the patient will develop macular degeneration at some point. Symptoms include distortion of straight lines, blurring of areas of print on a page, and dark or empty spaces that block the center of the field of vision. Are all cases of macular degeneration the same? There are two types of macular degeneration: The dry form and the wet form. The dry form accounts for approximately 90 percent of all cases of macular degeneration. In this form, vision loss progresses over a period of months or years and may affect only one eye. Only about ten percent of those with macular degeneration are diagnosed with the wet form, which can result in rapid and serious vision loss. It is referred to as "wet" because, in this type, tiny blood vessels that begin to grow beneath the retina break and leak blood and fluid. This distorts vision and causes scar tissue to form. How is macular degeneration treated? At this time, effective medical treatments are limited. In most cases, low-vision aids can be prescribed to help the patient lead a relatively normal life. Lasers have been used in treating the wet form of macular degeneration by sealing off leaky blood vessels. This cauterization procedure can arrest the spread of the abnormal blood vessels. However, the disease must be detected at an early stage for the treatment to be successful. |
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MACULAR DEGENERATION