Causes, Risk Factors, Symptoms and Treatment of Cataracts
A cataract is a clouding or yellowing of the eye’s lens that blocks light and makes vision blurry or hazy. This condition develops along with the thickening of the lens that occurs with aging. Cataracts are the most common cause of visual impairment associated with later life. Although more than half of people in the developed world over age 65 develop a cataract, not all cataracts impair vision significantly. Few people experience vision problems due to age-related cataracts before age 65.
Causes and Risk Factors for Cataracts
Risk factors that increase the chance of developing cataracts include family history of cataracts, high blood pressure, diabetes, obesity, smoking, alcohol abuse, therapy with corticosteroids, diuretics or certain tranquilizers, previous eye injury or eye surgery and long-term, unprotected exposure to the sun or other sources of ionizing radiation. Wearing sunglasses or regular eyeglasses treated with an anti-UV coating may help prevent or slow progression of age-related cataracts.
Symptoms of Cataracts
Cataracts are usually not associated with causing pain. The most common symptom that people with cataracts experience is trouble seeing in dim light. Another early sign of cataracts is increased sensitivity to glare as clouded lenses scatter light. Other common signals include needing brighter light to read, seeing colors as faded and requiring frequent changes in eyeglass prescription and less frequently also double vision in one eye and a feeling of a film over the eyes. However, many of these symptoms occur normally in later life, so it is often difficult to tell whether there really is a problem. But, one symptom that distinguishes cataracts from normal age-related changes to the eye is the failure of a new eyeglass prescription to improve vision.
The clouding of the lens can worsen with time until it causes blindness. However, cataracts can also stop worsening at some point and they may vary in the way they affect sight. Some interfere with near vision, others affect far vision. Some of the early changes in the lens caused by cataracts can temporarily compensate for the age-related changes known as presbyopia (diminished ability of the eye to focus on near objects). As a result, people in their 60s may sometimes find themselves able to read without glasses again, a phenomenon called “second sight.”
Eye surgery is currently the only effective treatment for cataracts. It consists in surgical removal of the eye’s lens, replacing it in most cases with a plastic lens inserted in the eye in the same position. Most modern cataract surgeries use a technique called phacoemulsification, in which the cloudy lens is broken up into small pieces using a high-frequency ultrasound device and these small pieces are then gently removed from the eye with suction. This procedure is typically highly successful.
Patients who still suffer reduced vision after eye surgery should contact their doctor. This can be due to the posterior capsule, a cellophane-like structure in which the eye’s original lens sits, becoming cloudy or wrinkled. In such a case laser surgery can be used to cut a hole through the capsule, allowing light to pass. In some cases, the eye’s lens and the lens capsule must both be removed and the patient’s vision may be then corrected with special thick eyeglasses or contact lenses.
Cataract surgery is performed under local anesthesia and typically does not require a hospital stay. Most patients can see well enough within a few days after surgery to be able to resume normal daily activities. Moreover, vision usually continues to improve over the following weeks and even months.
The chances of successful cataract surgery may not be as good in patients with other eye problems, such as glaucoma and these patients may need more time to recover. Complications associated with cataract surgery are relatively rare. If the surgical wound does not close properly, resulting fluid leakage may cause a form of glaucoma. Yet another potential risk is bleeding, which can even lead to blindness.
Therefore, you should know that it is not always necessary to have a cataract removed simply because it is there. The decision to undergo cataract surgery depends on how much your vision is affected by the cataract and how much it is likely to improve after surgery, what activities you must perform and the risk of surgery in your individual case.
Where to Find More Information: American Academy of Ophthamology