Ref: CHB/Flash/2006/26                                             Date: October 2, 2006

CHB NEWS FLASH 

The eye and the lens:

The crystalline lens in our eyes is similar to the lens in a camera. It actively focuses images on the retina, the light sensitive film at the back of the eye. This lens must be transparent to produce a clear sharp image. 

What is cataract?

A cataract is a clouding or opacification of the crystalline lens, the part of the eye responsible for focusing light and producing clear, sharp images. The lens is contained in a sealed bag or capsule. As old cells die they become trapped within the capsule. Over time, the cells accumulate causing the lens to cloud, making images look blurred or fuzzy. For most people, cataracts are a natural result of aging.

The incidence of cataract increases with age and is more likely to be seen after the age of 60. In may be seen in younger people as a consequence of eye injury, diabetes, malnutrition, chronic eye disease or long term use of certain medications especially steroids – in any form.

When cataracts are mentioned, people often think of a film that grows on their eyes causing them to see double or blurred images. However, a cataract does not form on the eye, but rather within the eye.
 

How is it treated?

Cataracts are among the eye conditions most amenable to a complete cure through surgery. 

The lens is removed through either a large (Extra capsular Cataract Extraction) or a small incision depending on the surgeons training and availability of equipment. The final visual outcome is more or less the same in both the methods though there are subtle advantages in small incision surgery. Techniques have been evolving, both these have now been overtaken by modern methods of cataract removal with new technology, as explained below. 

Phacoemulsification:

The most advanced technique with the maximum advantages is phacoemulsification (commonly referred to as laser). In this technique, the cataract is removed through an incision smaller than 3 mm, using an ultrasonic probe that gently breaks or emulsifies the cataract into tiny pieces which are then sucked out of the eye.  Recovery is quicker with minimum post operative pain and precautions. 

Intraocular lens: 

Cataract is replaced with a permanent clear intraocular lens (IOL). Modern intraocular lenses are foldable allowing them to be inserted into the eye through the small phacoemulsification incision, which is self sealing and requires no sutures. The intraocular lens insert plays the role of the original crystalline lens of focusing images on the retina. Cataract is usually done under local anesthesia, as a day care, requiring hospitalization for just few hours.  

Multifocal Intraocular Lenses:

Latest foldable intraocular lens which takes care of distance vision, intermediate vision and near vision, so that patients need not wear any glasses after the surgery.  

Advantages:

It increases the depth of focus and enhances the quality of vision.

Anatomy of an Eye:

“Community’s health – CHB’s priority”