Cataracts

Overview

A cataract is a clouding of the normally clear lens in the eye. It is possible to have a cataract in either or both eyes. Cataracts are very common affecting most Canadians over the age of 60 although they may occur as early as age 40. If left untreated they can cause blindness. Cataracts are detected through a comprehensive eye examination. If caught early new prescription eyeglasses and other vision aids may be all that is needed to improve vision. If not surgery is the only effective treatment.

Symptoms

The most common symptoms of a cataract are:

  • Cloudy or blurry vision.
  • Colours seem faded.
  • Glare in sunlight or under bright lights.
  • Poor night vision.
  • Double vision or multiple images in one eye.
  • Frequent prescription changes in your eyeglasses or contact lenses.

These symptoms also can be a sign of other eye problems. If you have any of these symptoms check with your eye care professional.

Causes

The lens consists mostly of water and protein. In a normal eye light passes through the lens to the retina where it is changed into nerve signals that are sent to the brain. In order for the retina to receive a sharp image the lens has to be clear. However if the protein clumps up it clouds the lens and reduces the light that reaches the retina. Most age-related cataracts develop from protein clumpings. In addition to age there are other risk factors for cataracts including:

Medical conditions. Diabetes and other systemic diseases glaucoma and metabolic abnormalities can cause cataracts.

Traumatic injuries. A blow to the eye intense heat or cold chemical injury exposure to radiation (usually associated with radiation therapy for cancer patients) and other injuries can cause cataracts.

Ultraviolet radiation (UVA or UVB). Long-term exposure to sunlight is believed to speed the development of cataracts.

Oral steroids and other medications. Oral steroids (such as prednisone) the gout medication allopurinol the breast cancer drug tamoxifen the heart medication amiodorone and the long-term use of aspirin have also been associated with cataracts.

Smoking. Studies indicate that smokers are twice as likely as nonsmokers to develop cataracts. Quitting can reduce the risk for developing cataracts.

Treatment

Cataracts are detected through a comprehensive eye examination. If caught early new prescription eyeglasses and other vision aids may be sufficient. However a doctor may recommend surgery when a cataract reduces your vision to the point that you can't do the things you like to do such as reading or driving. This involves replacing the cloudy lens with an artificial one a common procedure which is effective in about 90 per cent of cases. Although there are certain risk factors about 1.5 million cataract operations are performed in North America every year with few complications.

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

Prevention

If you are age 60 or older you should have regular comprehensive dilated eye exams. In addition to checking for cataracts your eye doctor can check for signs of age-related macular degeneration glaucoma and other vision disorders.

Certain lifestyle changes may help delay cataracts from forming:

  • Wear sunglasses and a brimmed hat to block ultraviolet sunlight
  • If you smoke stop
  • Eat plenty of leafy vegetables fruit and other foods rich in antioxidants

Additional Resources:

Canadian Ophthalmological Society