Managing Your Health as You Age:Eye Care Is Important Too
Visual impairment is very common in the older adult. Many eye disorders do not exhibit any symptoms until they enter their late stages. Therefore, it is important to schedule an appointment with your ophthalmologist for a medical exam every 2-4 years if you are between the ages of 40 and 64, and every 1-2 years if you are 65 years of age or older. If you are experiencing any changes in vision, schedule an appointment immediately. Although some disorders cannot be cured, there are ways to delay onset or progression. This patient aid outlines the symptoms, risk factors, prevention, and treatment options for cataract, glaucoma, and age-related macular degeneration—three very common disorders that affect the vision of older adults.
The development of cataracts is a normal part of aging, and usually progresses gradually over a period of years. Age-related cataracts, the most common type, usually form when protein, one of the main components of the lens, clumps up, clouding the lens and impairing vision. Cataracts can affect one or both eyes, and develop at varying rates. Common symptoms include painless blurring of vision, glare or light sensitivity (halos around lights), poor night vision, double vision in one eye, needing brighter light to read, fading or yellowing of colors, and frequent eyeglass prescription changes. You may be at greater risk for cataracts if you have a family history of the disease, medical problems such as diabetes, injury to the eye, certain medications (especially steroids), long-term unprotected exposure to sunlight, previous eye surgery, and if you are a smoker. To diagnose cataracts, your ophthalmologist may perform a visual acuity test (measures how well you see at various distances); a dilated eye exam (drops are used to dilate pupils and a magnifying lens examines your retina and optic nerve for damage); and tonometry (an instrument that measures the pressure inside the eye). In the early stages, symptoms may improve with a new eyeglass prescription, brighter lighting (using a 60- or 100-watt bulb and avoiding fluorescent lighting), magnifying lenses, or eye drops that widen the pupil, which may improve vision if the cataract is near the back of the lens. Other measures that may delay cataract development include wearing sunglasses that block ultraviolet light or a hat or visor to shield your eyes from the sun, and quitting a smoking habit. A cataract can only be removed by surgery, which is usually recommended when your ability to function in daily activities decreases or if it interferes with treatment of another eye problem, such as macular degeneration. Surgery often involves implanting an intraocular lens when the cataract is removed. Although the success rate is very high (approximately 95%), and there are normally very few side effects, vision may not be fully restored, or other eye problems, such as macular degeneration or glaucoma, may affect vision post-surgery.
Glaucoma is a leading cause of blindness in the United States. The most common form is open-angle (chronic) glaucoma, which often develops when fluid draining in the eye is impaired, increasing pressure and eventually damaging the optic nerve (the nerve connecting the eye to the brain), which causes blindness if left untreated. Risk factors for open-angle glaucoma include advancing age, family history, health problems such as diabetes, nearsightedness, and African-American or Mexican-American descent. When glaucoma first develops, there are usually no symptoms, but as the optic nerve becomes more damaged, there is a gradual loss of peripheral (side) vision. Blindness results if all optic nerve fibers die. Other symptoms may include blurred or foggy vision, headache, or seeing rainbow-colored halos around lights. Glaucoma can be detected by regular eye exams by your ophthalmologist. Tests include the visual acuity test; visual field test (measures your peripheral vision); dilated eye exam; tonometry; and pachymetry (an ultrasonic wave instrument that measures the thickness of your cornea). Open-angle glaucoma cannot be prevented or cured (ie, loss of vision cannot be restored), but it can usually be controlled, and further vision loss can be prevented with treatment. Treatment includes medication (eye drops or oral medications that lower eye pressure or cause the eye to make less fluid), laser surgery (to improve fluid drainage inside the eye), and eye surgery (to create a new drainage canal).
AGE-RELATED MACULAR DEGENERATION
Age-related macular degeneration (AMD) affects central vision. The two types of AMD are dry macular degeneration and wet macular degeneration. Dry AMD is more common and is caused by aging and thinning of the tissues of the macula, a small area in the retina at the back of the eye. Yellow deposits under the retina (drusen) are an early sign of dry AMD. This dry form usually results in only gradual central visual loss. The wet form, however, results in a more rapid, severe vision loss. It is considered to be an advanced form of AMD caused by formation of abnormal blood vessels that leak fluid or blood. Symptoms of AMD include blurred vision, straight lines appearing wavy, dark or empty spots blocking the center of your vision, and difficulty seeing at a distance, distinguishing colors, and seeing details (eg, faces). Symptoms may be minor and unnoticeable in the early stages, but central vision loss may become more prominent after both eyes are affected. The greatest risk factor is increasing age; other risk factors include smoking, a family history of AMD, and being Caucasian. Your ophthalmologist will perform a visual acuity test, dilated eye exam, and tonometry to test for AMD. You may also be asked to look at a chart that resembles graph paper, called an Amsler grid; if its checkerboard pattern appears distorted, you may have this disorder. Research has shown that vitamins and minerals such as zinc and antioxidants may slow progression of dry AMD. Wet AMD is usually treated with laser surgery (a strong light beam destroys the abnormal new blood vessels), photodynamic therapy (a drug activated by light destroys the new blood vessels), or injections (a drug involving multiple injections into the eye blocks a growth factor promoting the growth of the abnormal new blood vessels). All treatments seek to slow the rate of central vision loss. Sources: American Academy of Ophthalmology, MEDLINE Plus, National Eye Institute, American College of Surgeons