The following is a description of the major eye diseases.
Cataracts
Cataract is the clouding of the normally transparent lens that is associated with advancing age, but it can be caused by other factors. Over one million cataract operations are performed each year. Most are combined with the implanting of an artificial lens and can be done as same-day surgery without complications.
Recent studies show that exposure to UV light (sunlight) may contribute to the development of cataracts, and by wearing the proper sunglasses and a wide-brimmed hat you may protect your eyes from the early onset of this condition. However, by the age of seventy-five, almost everyone has developed a cataract. Fortunately, cataract surgery is the most frequently performed operation in the United States and is considered a safe procedure with most costs covered by Medicare.
Glaucoma
Although glaucoma is considered the most preventable form of blindness, it still claims the vision of almost eighty thousand Americans. It is often called the "sneak thief because by the time you discover that you have glaucoma, it has already damaged your vision. It is estimated that probably one million people are at risk for losing their vision because they have no symptoms and have not had the comprehensive eye examination that would detect the disease. African Americans are at high risk because of the inherited form of glaucoma that has become the most prevalent cause of blindness among members of this ethnic group. Glaucoma is actually a group of diseases in which the patient experiences a loss of visual field due to damage to the optic nerve caused by increasing intraocular pressure (lOP). Open-angle glaucoma is the most common form of the disease in which fluid is blocked in the front section of the eye causing damage to the optic nerve. The onset of angle-closure glaucoma, which is caused by pressure building between the iris and cornea, can be chronic (the lOP increases slowly and persistently) or acute (lOP increases suddenly). Both open-angle and angle-closure can be primary (attributed to a known cause such as inherited disease) or secondary (caused by a previous injury or illness). People who suffer from the little-understood normal or low-tension glaucoma sustain damage to the optic nerve even though their lOP, is within normal ranges. Childhood or congenital glaucoma affects infants, young children, and adolescents. Fortunately, if detected early, treatment is available in the form of oral medications or eye drops that lower lOP and surgery that uses either lasers or ophthalmic surgical instruments.
Retinal Diseases
Retinitis pigmentosa (RP) is the major cause of blindness for people six to sixty, and one in every eighty people carries the gene for RR There is no known cure for this disease, which makes it one of the frontiers of ophthalmic research. Great progress is being made on identifying the genetic makeup of RP, and in the future, researchers hope to be able to genetically engineer a change for carriers of this blinding disorder. If you know that you have diabetes, the best way to prevent the adverse effects of the disease on your eyes or diabetic retinopathy is to control your diabetes. If your vision is affected, there is a common outpatient surgery called laser photocoagulation that when performed by a qualified ophthalmologist will seal leaking blood vessels. Vitrectomy is a procedure that is used for more severe cases that require that the blood-engorged vitreous be removed and replaced with a clear fluid. In most cases of macular degeneration, the sensitive tissues of the macula slowly dry out and become thinner, causing a dimming of vision. Low-vision aides that combine magnification and bright lights help with degenerating sight, and many people believe that dietary supplements of zinc and antioxidant can stabilize and improve vision. For the rarer forms of wet macular degeneration, laser surgery is helpful in destroying the abnormal blood vessels that cause a blind spot in the visual field. Research continues to uncover the causes of macular degeneration and to substantiate the use of antioxidants in its treatment.
Strabismus, Amblyopia and Ptosis
These diseases affect at least 2 to 4 percent of children. Strabismus is the misalignment of the two eyes. It is sometimes present at birth or can occur later in life as a paralysis of the muscles that control the position of the eye. Treatment includes corrective lenses and sometimes surgery. Amblyopia, also known as "lazy eye," is a misfocus of one or both eyes that prevents normal development of vision. Treatment can include placing a patch over the stronger eye in order to retrain the amblyopic one.
Ptosis is a condition that causes the upper eyelid to droop and may cause amblyopia in both children and adults. Surgery to tighten the levators, or eyelid-lifting muscles, is usually the only solution to this problem.
AIDS and the Eye
Most people know that Acquired Immunodeficiency Syndrome (AIDS) is transmitted through transfusions of infected blood. But what about contact with tears? No cases of AIDS have ever been attributed to contact with tears, even though the HIV virus can be found in the tears of infected persons. For people with AIDS, regular eye examinations are of critical importance. There are several complications of the disease that affect vision, including white spots or "cotton wool spots" on the retina, red eyes, detached retina, and Kaposi's sarcoma of the eyelid or white of the eye. Fortunately, ophthalmologists have several medications that eliminate or stabilize these conditions.
Low Vision
People of all ages can be affected by low vision, which means that their vision cannot be corrected with conventional glasses and contact lenses, but they are not considered legally blind. Many of these people with low vision can read, play cards, watch television, and in other ways function and enjoy life with the use of special low-vision devices. These include:
- magnifying spectacles that are stronger than most ordinary glasses
- hand and stand magnifiers that may also have a light source
- telescopes for viewing distant items
- closed circuit TV to enlarge images on the TV screen
- special home and work devices, such as enlarged phone dials and clock faces
