Tuesday 19 February 2013

What is Cataract?


What is Cataract?
Cataract is clouding of the natural (clear) lens, so light rays are not able to reach & properly focus on the posterior part of the eye (retina). A normally clear lens allows light to pass through to the back of the eye, so that the patient can see well-defined images. If a part of the lens becomes opaque light does not pass through easily and the patient's vision becomes blurry - like looking through cloudy water or a fogged-up window. The more opaque (cloudier) the lens becomes, the worse the person's vision will be. Cataract can be found at any age as there are many reasons for cataract to form. Cataract is most commonly found with aging. Cataract can occur in one or both eyes but it does not spread from one eye to another.

Cataract is 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.

What Causes Cataract?
Lens is made up of water and protein and hence it is very clear and pure. But with growing age, this protein starts clumping together and this can cloud some area of the lens. This is what is known as cataract and if you will not get it treated then it will spoil the entire lens by clouding it more and more. Neglected eye with cataract hyper maturation can have other associated eye problems like inflammation & glaucoma. This can worsen the visual outcomes of cataract surgery, even permanent blindness. Smoking and diabetes are also responsible for causing cataract. People can have cataract in their forties and fifties also. But by the age of 60 the clouding of the lens is more and thus many people get diagnosed with cataract in this age.

Factors that may speed up cataract formation are:
  • Diabetes
  • Eye inflammation
  • Eye injury
  • Family history of cataracts
  • Long-term use of corticosteroids (taken by mouth) or certain other medications
  • Radiation exposure
  • Smoking
  • Surgery for another eye problem
  • Too much exposure to ultraviolet light (sunlight)
In many cases, the cause of cataract is unknown.

Types of Cataract
Secondary cataract – when you get treated for any other eye problems like glaucoma, you have some chances of getting this type of cataract. It is also a common condition in people with diabetes.

Congenital cataract – Some infants are born with cataract or may develop it in their early childhood. This happens in both the eyes. This cataract will be quite small and hence it will not affect the vision of your child. This condition can be treated if the cataract starts affecting the normal vision. Replacing the lens can cure this.

Traumatic cataract – when you get some eye injury then there are chances of you getting this kind of cataract.

Radiation cataract – Due to some kind of exposure to some types of radiation this kind of cataract can affect you.

Symptoms of Cataract
Adult cataracts develop slowly and painlessly. Vision in the affected eye or eyes slowly gets worse.
  • Mild clouding of the lens often occurs after age 60, but it may not cause any vision problems.
  • By age 75, most people have cataracts that affect their vision.
Visual problems may include the following changes:
  • Being sensitive to glare
  • Cloudy, fuzzy, foggy, or filmy vision
  • Difficulty seeing at night or in dim light
  • Double vision
  • Loss of color intensity
  • Problems seeing shapes against a background or the difference between shades of colors
  • Seeing halos around lights
Cataracts generally lead to decreased vision, even in daylight. Most people with cataracts have similar changes in both eyes, although one eye may be worse than the other. Many people with this condition have only mild vision changes.

Other symptoms may include:
  • Frequent changes in eyeglass prescription
Detection of Cataract
A Visual acuity test, complete eye examination on slit lamp with retina examination is sufficient for cataract assessment. Other diagnostic tests are rarely needed, except to rule out other possible causes of poor vision.

Treatment of Cataract
The following may help people who have an early cataract:
  • Better eyeglasses
  • Better lighting
  • Magnifying lenses
  • Sunglasses
As vision gets worse, you may need to make changes around the home to avoid falls and injuries.

The only treatment for a cataract is surgery to remove it. Surgery is done if you cannot perform normal activities, such as driving, reading, or looking at computer or video screens, even with glasses.

If a cataract is not bothersome, surgery is usually not necessary. Cataracts usually do not harm your eye, so you can have surgery when it is convenient for you.

However, some people may have additional eye problems, such as diabetic retinopathy, that cannot be treated without first having cataract surgery.

Prognosis of Cataract
Cataract surgery usually gives a good visual outcome, except in cases where there is other condition of retina such as macular degeneration present.

Ophthalmologists can usually, but not always, determine this in advance.

Complications
Early diagnosis and treatment are key to preventing permanent vision problems.

Although rare, a cataract that goes on to an advanced stage (called a hypermature cataract) can begin to leak into other parts of the eye. This may cause a painful form of glaucoma and inflammation inside the eye.

Eye check up
Call for an appointment with your health care provider if you have:
  • Decreased night vision
  • Problems with glare
  • Vision loss
Prevention
The best prevention involves controlling diseases that increase the risk of a cataract, and avoiding exposure to factors known to promote cataract formation.

Wearing sunglasses when you are outside during the day can reduce the amount of ultraviolet (UV) light your eyes are exposed to. Some sunglasses do not filter out the harmful UV. An optician should be able to tell you which sunglasses filter out the most UV. For patients who smoke cigarettes, quitting will decrease the risk of cataract.

Eat plenty of fruits and vegetables, whole grains, unrefined carbohydrates, good quality fats (avocado, olive oil, omega oils), and either plant sourced proteins or lean animal sourced proteins. Sleep well for seven hours at night, exercise, control obesity & diabetes.