Cataract

 

Cataract

Definition

Types of cataracts include:

Age-related cataracts : These cataracts form because of aging.

Congenital cataracts : Babies are sometimes born with cataracts as a result of an infection, injury, or poor development before they were born, or they may develop during childhood.

Secondary cataracts : These develop as a result of other medical conditions, like diabetes, or exposure to toxic substances, certain drugs (such as corticosteroids or diuretics), ultraviolet light, or radiation.

Traumatic cataracts : These form after an injury to the eye. 

Source : WebMD

 

Organ

The organ affected by a cataract is the lens, which loses progressively its transparency and become opaque.

 

Symptoms

The most common symptoms of a cataract are:

  • Cloudy or blurry vision.
  • Colors seem faded.
  • Glare. Headlights, lamps, or sunlight may appear too bright. A halo may appear around lights.
  • Poor night vision.
  • Double vision or multiple images in one eye. (This symptom may clear as the cataract gets larger.)
  • Frequent prescription changes in your eyeglasses or contact lenses.

Source : NEI

 

Frequency

Cataracts are the most common cause of vision loss in people over age 40 and is the principal cause of blindness in the world. In fact, there are more cases of cataracts worldwide than there are of glaucoma, macular degeneration and diabetic retinopathy combined, according to Prevent Blindness America (PBA).

Today, cataracts affect more than 22 million Americans age 40 and older. And as the U.S. population ages, more than 30 million Americans are expected to have cataracts by the year 2020, PBA says. 

Source : All About Vision

 

Causes

There are several underlying causes of cataracts. These include:

  • an overproduction of oxidants, which are oxygen molecules that have been chemically altered due to normal daily life
  • smoking
  • ultraviolet radiation
  • the long-term use of steroids and other medications
  • certain diseases, such as diabetes
  • trauma
  • radiation therapy 

Source : Healthline

 

Evolution

In most cases, cataracts will continue to worsen over time, causing continual reduction of vision. Driving can be affected — which could be dangerous — and so can overall quality of life.

Many people become legally blind from untreated cataracts, and cataracts can even cause total blindness if left untreated for long periods. 

Untreated cataracts can become "hyper-mature" — a condition that makes them more difficult to remove and more likely to cause cataract surgery complications.

Source : All About Vision

 

Prevention

To reduce your risk of developing cataracts:

  • protect your eyes from UVB rays by wearing sunglasses outside
  • have regular eye exams
  • stop smoking
  • eat fruits and vegetables that contain antioxidants
  • maintain a healthy weight
  • keep diabetes and other medical conditions in check

Source : Health Line

 

Diagnosis

Cataract is detected through a comprehensive eye exam that includes:

  • Visual acuity test: This eye chart test measures how well you see at various distances.
  • Dilated eye exam: Drops are placed in your eyes to widen, or dilate, the pupils. Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of damage and other eye problems. After the exam, your close-up vision may remain blurred for several hours.
  • Tonometry: An instrument measures the pressure inside the eye. Numbing drops may be applied to your eye for this test.

Your eye care professional also may do other tests to learn more about the structure and health of your eye. 

Source : NEI

 

Treatment

The symptoms of early cataract may be improved with new eyeglasses, brighter lighting, anti-glare sunglasses, or magnifying lenses. If these measures do not help, surgery is the only effective treatment. Surgery involves removing the cloudy lens and replacing it with an artificial lens.

A cataract needs to be removed only when vision loss interferes with your everyday activities, such as driving, reading, or watching TV. You and your eye care professional can make this decision together. Once you understand the benefits and risks of surgery, you can make an informed decision about whether cataract surgery is right for you. In most cases, delaying cataract surgery will not cause long-term damage to your eye or make the surgery more difficult. You do not have to rush into surgery.

Sometimes a cataract should be removed even if it does not cause problems with your vision. For example, a cataract should be removed if it prevents examination or treatment of another eye problem, such as age-related macular degeneration or diabetic retinopathy.

If you choose surgery, your eye care professional may refer you to a specialist to remove the cataract.

If you have cataracts in both eyes that require surgery, the surgery will be performed on each eye at separate times, usually four weeks apart. 

 

What happens during surgery?

At the hospital or eye clinic, drops will be put into your eye to dilate the pupil. The area around your eye will be washed and cleansed.

The operation usually lasts less than one hour and is almost painless. Many people choose to stay awake during surgery. Others may need to be put to sleep for a short time. If you are awake, you will have an anesthetic to numb the nerves in and around your eye.

After the operation, a patch may be placed over your eye. You will rest for a while. Your medical team will watch for any problems, such as bleeding. Most people who have cataract surgery can go home the same day. You will need someone to drive you home.

Source : NEI

Images

  Magnified view of a cataract seen on examination with a slit lamp

Cataract in human eye

SourceBy Rakesh Ahuja, MD (Own work) [GFDL], via Wikimedia Commons

 

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