Cataract

A cataract is a clouding of the normally clear crystalline lens inside the eye.

There are many different types of cataracts. The three most common types of age-related cataracts are: nuclear sclerosis, cortical, and posterior sub capsular. Nuclear cataracts tend to progress slowly while cortical and posterior sub capsular cataracts vary in their rate of progression.

While most cataracts progress slowly, they are unpredictable in their rate of progression. Some cataracts will get significantly worse within a few weeks while other cataracts remain unchanged for many years.



Symptoms

In the early stages, only a doctor can detect a cataract because there may not be any symptoms. When you do start to notice changes in vision, they may include:

     •  blurry distance vision, especially outdoors;

     •  streaks or rays of light seeming to come from headlights
         and stop lights;

     •  instinctively shading your eyes from the sun or feeling
         more comfortable wearing a visor;

     •  print appearing faded and lacking in contrast;

     •  colors appearing faded or changed in hue. Blue may appear
         to be green and yellow may look white.

Because these may also be symptoms of other eye conditions, it is important to see your eye doctor annually, or whenever you notice a persistent change in vision.



Cause

Although we do not yet know what causes cataracts, studies have identified the following risk factors:

     •  Aging

     •  Long-term exposure to sunlight

     •  Cigarette smoking

     •  High cholesterol/triglycerides

     •  Diabetes

     •  Certain eye conditions - cataract is often associated with
         myopia, retinitis pigmentosa, and retinopathy of prematurity

     •  Cortisone medication taken orally for a long time

     •  Eye injury



Detection

To detect a cataract, an eye care professional examines the lens. A comprehensive eye examination usually includes:

     1.  Visual acuity test

         This eye test, which measures how well you see at various distances, has two components. It measures accurate vision without correction, as well as best corrected vision confirmed by refraction.

     2.  Pupil dilation

         The pupil is widened with eye drops to allow your eye care professional to see more of the lens and retina and look for other eye problems.

     3.  Tonometry

         This is a standard test to measure fluid pressure inside the eye. Increased pressure may be a sign of glaucoma. One type of the test uses a purple light to measure pressure. Another type, known as the "air puff" test, measures the resistance of the eye to a puff of air. Your eye care professional may also do other tests to learn more about the structure and health of your eye.



Cure

There are no medications, eye drops, exercises or glasses that will cause cataracts to disappear once they have formed. Surgery is the only way to remove a cataract. When you are no longer able to see well enough to do the things you like to do, cataract surgery should be considered



Surgery



         Cataract surgery is one of the most common operations performed in the United States. It also is one of the safest and most effective types of surgery. In about 90 percent of cases, people who have cataract surgery have better vision afterward.

         There are two types of cataract surgery. Your doctor can explain the differences and help determine which is better for you. These are called ohacoemulsification (phaco), and extracapsular cataract surgery. In phacoemulsification an incision about 3 mm long is made in the eye where the clear front covering of the eye (cornea) meets the white of the eye (sclera). A small surgical instrument is inserted into the eye and lens capsule, and the anterior portion of the lens capsule is removed

         Extracapsular cataract surgery is also called extracapsular cataract extraction (ECCE), involves removing the lens with the cataract from the lens capsule. In most cases, the lens will be replaced with an intraocular lens implant (IOL). If an IOL cannot be used, contact lenses or eyeglasses must be worn to compensate for the lack of a natural lens.

         As with any surgery, cataract surgery poses risks, such as infection and bleeding. Before cataract surgery, your doctor may ask you to temporarily stop taking certain medications that increase the risk of bleeding during cataract surgery. After surgery, you must keep your eye clean, wash your hands before touching your eye, and use the prescribed medications to help minimize the risk of infection. Serious infection can result in loss of vision.