Cataract – causes, symptoms and treatment

A cataract is the opacification of the lens of the eye producing a clouding or fogging of the vision. It is one of the most common causes of blindness in the world along with glaucoma, trachoma, vitamin A deficiency and onchocerciasis.

The common types of cataract are:

1. Age related cataract:  As the name suggests it is due to aging. The lens is mostly made up of water and protein and is clear, which helps in focusing light on to the retina. As age progresses the protein in the lens starts clumping, which initially decreases the clarity, but slowly obstructs light causing decrease in vision.
2. Congenital cataracts: Babies born with cataract due to infection, trauma or poor development before birth or during their childhood.
3. Secondary cataract: It occurs due to the presence of other medical conditions like diabetes, use of drugs like steroids, or exposure to toxic substances or radiation.
4. Traumatic cataract: Caused due to trauma to the eye.

Besides advancing age, common factors that contribute to the development of cataract are:

• Ultraviolet radiation from sunlight and other sources
• Diabetes
• Hypertension
• Obesity
• Smoking
• Prolonged use of corticosteroid medications
• Statins used to reduce cholesterol level
• Previous eye injury or inflammation
• Previous eye surgery
• Hormone replacement therapy
• Significant alcohol consumption
• High myopia
• Family history

Symptoms of cataract:

• 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
• Frequent prescription changes in eyeglasses or contact lenses

Treatment:

The symptoms of early cataract can be managed with new eyeglasses, better and 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.

The two types of cataract surgery that are usually performed are:

1. Phacoemulsification: A small incision is made on the side of the cornea, the clear, dome-shaped surface that covers the front of the eye. The doctor inserts a tiny probe into the eye. The phacoemulsification device emits ultrasound waves that soften and break up the lens so that it can be removed by suction. Most cataract surgery done today is by phacoemulsification, also called "small incision cataract surgery."
2. Extracapsular surgery: The doctor makes an incision on the side of the cornea and removes the cloudy core of the lens in one piece. The rest of the lens is removed by suction.

An artificial lens known as Intra Ocular Lens (IOL) replaces the natural lens in the capsule, which helps in focusing the light on to the retina giving a clear vision.

It’s a day care surgery where the person is ambulatory and is able to see immediately after the surgery,  but cautiously so as not to strain the eyes. Bending, lifting heavy objects, and driving should be avoided for some time.