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Feature:
Treating Cataracts

Cataracts and Other Common Eye Diseases

Anatomy of Human Eye

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In a normal eye, light passes through the transparent lens to the retina. The lens helps focus your eyes on what you see. It must be clear for the retina to receive a sharp image. The lens is made of mostly water and protein. The protein is arranged in a precise way that keeps the lens clear. As we age, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract.

Comprehensive Dilated Eye Exam

A comprehensive dilated eye exam is a procedure in which an eye care professional examines your eyes to look for common vision problems and eye diseases, many of which have no early warning signs. Regular comprehensive eye exams can help you protect your sight and make sure that your eyes are healthy and you are seeing your best. This eye exam includes the following tests.

Dilation: Drops are placed in your eyes to dilate, or widen, the pupils. Your eye care professional uses a special magnifying lens to examine your retina to look for signs of damage and other eye problems, such as diabetic retinopathy or age-related macular degeneration. A dilated eye exam can also reveal cataracts and any damage to the optic nerve from glaucoma. After the examination, your close-up vision may remain blurred for several hours.

normal vision

Normal: A scene as it might be viewed by a person with normal vision.
Photo courtesy of National Eye Institute

Tonometry: In this test, gentle pressure is applied to the outside of the eye to measure the pressure inside. The outside pressure may be produced by a small probe or by an air puff. Numbing drops may be applied to your eye first. Elevated pressure is a possible sign of glaucoma.

Visual field test: This test measures your side (peripheral) vision to determine if you have lost any—a sign of glaucoma.

Visual acuity test: This test measures how clearly you can see letters on an eye chart. The test is generally done at a distance of 20 feet, and a result of 20/20 indicates normal visual acuity. A result of 20/40 means that at 20 feet you can see what a person with normal vision can see at 40 feet.

People with diabetes, glaucoma, and age-related macular degeneration are more likely to develop a cataract.

Diabetic Eye Disease

Vision with Diabetic Retinopathy

Diabetic Retinopathy: A scene as it might be viewed by a person with diabetic eye disease.
Photo courtesy of National Eye Institute

People with diabetes are at risk for diabetic retinopathy, cataract, and glaucoma. Diabetic eye disease refers to this group of eye problems that people may face as a complication of diabetes. There are no symptoms in the early stages of diabetic eye diseases.

Treatment:

To prevent vision loss from diabetic eye disease, people with diabetes should control their levels of blood sugar, blood pressure, and blood cholesterol. Depending on the stage and type of diabetic eye disease, various treatments are used, including laser surgery, vitrectomy surgery (removal of blood from the center of the eye), and injections of drugs into the eye.

Cataracts

Vision with Cataracts

Cataract: A scene as it might be viewed by a person with cataract
Photo courtesy of National Eye Institute

Cataracts are a clouding of the lenses in your eyes, causing blurry vision. Unlike many eye diseases, they are usually not dangerous to the health of the eye and are curable with surgery. A cataract can occur in one or both eyes. It cannot spread from one eye to the other. By age 80, more than half of all Americans will have a cataract or have had cataract surgery.

Common symptoms are:

  • Blurry vision
  • Colors that seem faded
  • Glare
  • Not being able to see well at night
  • Double vision
  • Frequent prescription changes in your eyewear

At first new glasses, brighter lighting, anti-glare sunglasses, or magnifying lenses can help with early symptoms. However, surgery is the only effective treatment. It involves removing the cloudy lens and replacing it with an artificial lens.

Age-Related Macular Degeneration

Vision with age-related Macular Degeneration

Macular Degeneration: A scene as it might be viewed by someone with age-related macular degeneration.
Photo courtesy of National Eye Institute

Age-related macular degeneration (AMD) is a leading cause of vision loss in Americans 60 and older. It destroys the sharp, central vision needed to see objects clearly. Reading, driving, watching television, and routine daily tasks are affected. AMD causes cells in the macula—the part of the eye that allows you to see fine detail—to die. It does not cause pain.

There are three stages of AMD: early, intermediate, and late.

In the early stages, AMD has few symptoms, so it is important to have regular eye examinations.

Intermediate AMD may cause some vision loss, but most people will not experience any symptoms. It is important to have a dilated eye exam to detect intermediate AMD.

Late-stage AMD is comprised of two types: geographic atrophy (also called dry AMD), and neovascular AMD (also called wet AMD). Both cause vision loss. It is possible to have both geographic atrophy and neovascular AMD in the same eye, and either condition can appear first.

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Treatment

Although currently there is no cure for AMD, regular eye exams can detect the disease and lead to early treatment, when it is most effective and often sight-saving. NEI-supported research shows that a specific combination of vitamins and minerals can help slow the progression to advanced AMD. Advanced AMD is treated with injections of drugs into the eye and lasers.

Glaucoma

Vision with Glaucoma

Glaucoma: A scene as it might be viewed by a person with glaucoma.
Photo courtesy of National Eye Institute

Glaucoma is a group of diseases that can damage the eye's optic nerve and result in vision loss and blindness. Open-angle glaucoma is the most common form of the disease. Often there are no symptoms in the early stages, but can be detected through a dilated eye exam.

Treatment:

Glaucoma treatments include medicines, laser trabeculoplasty, conventional surgery, or a combination of any of these. While these treatments may save remaining vision, they do not improve sight already lost from glaucoma.

Read More "Treating Cataracts" Articles

Cataract Q&A / Dr. Rachel Bishop's Top Tips for Your Eyes / Cataracts and Other Common Eye Diseases

Summer 2014 Issue: Volume 9 Number 2 Page 10-11