Indira Gandhi Eye Hospital and Research Centre
Indira Gandhi Eye Hospital and Research Centre
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Cataract

A cataract is the clouding of the eye’s natural lens. The lens acts very much like the camera’s lens. It focuses light on the retina at the back of the eye and adjusts the eye’s focus so that we can see clearly, far and near. The lens is made up of protein and water, with the protein being arranged in a manner that allows the light to pass through and the lens to remain clear. Changes in the arrangement of the protein – clumping together – cause clouding of the lens, leading to cataract.

Types of cataract

Senile Cataract

This is the most common type of cataract, is related to ageing and occurs in people above the age of 50.

Congenital Cataract

Children very rarely suffer from cataract. However this may occur due to infection of the mother during pregnancy, or may be hereditary.

Traumatic Cataract

This type of cataract may occur at any age due to eye injury.

Secondary Cataract

This type of cataract is a by-product of diseases such as glaucoma, iritis, eye tumours and diabetes.

Drug-induced Cataract

Prolonged use of steroid drugs as treatment may cause type of cataract.

Symptoms

Blurring of vision A feeling that a film covering your eyes Sensitivity to bright light Colours not appearing as bright as they did earlier

Causes

No one is sure why cataract occurs when we age. Some experts have suggested that exposure to ultra-violet light may be responsible for its occurrence, and that dark glasses should be used as a protective measure. Some others have suggested that exposure to radiation could also be a possible cause.

Treatment

Surgery is the only treatment for cataract.

Earlier method

Before the advent of intra ocular lenses (IOLs), surgery was performed under local anaesthesia. A 10 mm incision was made, the cataract lens removed, replaced with an Aphakic glass, and the incision closed with sutures. After the surgery, the patient had to wear ophakic spectacles. However, these ophakic glasses are heavy, images seen are distorted and appear larger than normal, and the field of vision is restricted.

IOL replacement

IOL is a tiny transparent convex lens made of polymethyl methacrylate (a harmless plastic substance). The patient does not have to wear spectacles after surgery unless prescribed by the ophthalmologist, the images see are clear and undistorted, there is return of full vision, and normal field of vision.

Surgery takes 15 minutes. A 10 mm incision was made, the cataract lens removed, replaced with IOL, and the incision closed with sutures. The procedure is performed under local anaesthesia.

Sutureless or phaco surgery is the more recent method. The procedure is performed under local anaesthesia, a 5 mm incision is made, and the cataract lens is broken into small pieces through ultrasonic waves and the pieces removed by a needle. The specially prepared IOL is inserted and no sutures are required for healing.

Phaco surgery has several advantages over the traditional methods: the patient need not wait for the cataract to mature; the incision is small and there is no need for sutures to be removed; there is no irritation or watering of the eye and the patient does not have to use eye drops for a long time; there is no hospital stay, just one post-operative visit; and there is stable refraction after a month.

However, the decision whether phaco surgery can be performed or not lies with the ophthalmic surgeon.