Removing the cloud in the lens
In our continuing series on common surgical procedures, Dr. Melanie Amarasooriya looks at the cataract operation

Do you feel that your vision is getting blurred and the glare of the head lamps of other vehicles makes it more difficult to drive? You may need to get your vision checked for these could be early symptoms of cataract.

Cataract is one of the commonest conditions that affect your eyesight, especially in the elderly. It is also one of the commonest surgical procedures performed today. Here Dr. Maduwanthi Dissanayake, a consultant ophthalmologist and senior lecturer in the Faculty of Medicine, Colombo explains the condition and its surgical treatment.

Although a cataract is a degenerative change that occurs with aging it is not essentially a condition of the elderly. Cataract can also occur in the young and at an earlier age in diabetics, patients taking steroid drugs for a long time, patients who have sustained significant trauma to the eye or people with longstanding inflammatory conditions of the eye. In rare cases this can be present in newborn babies as a congenital abnormality which needs urgent medical attention.

Cataract in simple terms can be explained as clouding of the lens of the eye. The eye lens is a transparent protein covered with another transparent capsule. It allows light to pass through it, converging onto the retina, at the back of the eye, making an image. This process helps us to see. When there is cataract, the proteins get clumped so that the transparent nature of the lens is lost. This opacification makes the vision clouded.

The existing lens needs to be surgically removed and a new artificial one inserted. So far, no medication has been discovered to cure or slow down the progression of the condition. Left untreated, the lens will eventually become so clouded that it is impossible to see any detail at all.

Before the surgery you will be assessed by the ophthalmologist to identify the type and the severity of the cataract. The ophthalmologist will check your vision by asking you to read a chart, called the Snellen's chart. Then, your eye will be examined under a 'slit lamp', a special kind of microscope like equipment. The procedure is not uncomfortable or painful. It is just looking into your eyes with a special lamp. Sometimes a drop of medication will be administered to your eye to widen the pupil, so that the ophthalmologist can have a better view of the interior of the eye.

After putting in the eye drops it will take about 20 minutes for the pupil to get dilated, and the eye can be examined. Once the examination is over it will take about another one to two hours for the pupil to return to its normal size. Therefore, you will feel the glare markedly as you come out, so always get another person to accompany you. It is not safe to drive until your blurred vision is settled. If there is mature cataract, you may need an eye scan to find out whether there is pathology in the back of the eye.

There is no truth to the belief that the cataract needs to get matured to be operated. It could be done as soon as the doctor and the patient decide that the loss of vision is significantly affecting the patient's activities.

In this operation, the lens is broken down into tiny pieces which are removed through a small incision in the eye. The lens is replaced with an artificial one which is made out of biologically inert material. This allows patients to keep the lens permanently in the eye without having reactions.

Cataracts typically occur in both eyes, but they are usually treated one at a time, to allow the first eye to recover. There is usually an interval of three months between each operation. Cataract surgery is most often performed as a day-case, so that you can go home the same day. It is a commonly performed, safe procedure, which takes about 15 to 20 minutes.

  • The procedure is done under local anaesthesia which means you will be awake during the surgery. However, you will neither feel pain nor will you be able to see with the eye during the surgery. If needed the anaesthetist will give medication to sedate you.
  • Once the anaesthetic has taken effect, your surgeon will make a tiny incision on the surface of your eye looking through a microscope using very fine instruments. This incision is usually so small that no stitches are needed.
  • The surgeon then will break up the cloudy lens (cataract) into small pieces using ultrasound energy. This will be removed through a small tube.
  • An artificial lens (the intraocular lens) will be introduced into your eye into the capsule of the original lens which is left.
  • This can stay permanently in your eye.

Following the surgery, aftercare is crucial.You will have to wear a protective gauze pad to cover the eye for a day.

The numbness that you feel following the anaesthetic will improve in a few hours and you will be able to see with the operated eye in few days. The vision will gradually improve. However, the wounds will take months to heal completely.
There will be a follow up visit within a few days of the procedure. You will have to continue the eye drops prescribed by the doctor, exactly the way it was asked to prevent infections and reduce inflammation.

You can resume normal activities such as moving around but be careful because it's hard to judge distances with one eye covered.

Important things to remember while recovering from cataract surgery:

  • Try not to touch or rub your eye.
  • Keep soap and shampoo out of your eyes (it's sensible to avoid washing your hair for the first three or four days).
  • In the first few weeks after the operation, avoid heavy lifting or strenuous exercise as this can increase the pressure in your eye and could put a strain on your healing scar.
  • If you suffer more than mild pain, or you experience impairment of vision or increasing redness of your eye, you should contact the doctor for advice without delay.
  • Use the medication prescribed according to medical advice.
  • If it doesn't cause any discomfort, you can watch TV or read from the next day onwards.

As in any surgical procedure cataract surgery can have complications. However, since this is a well practised safe surgery complications are minimal. Mild irritation, redness, tearing is normal following the surgery.

Very rarely there could be infections, problems in the other parts of the eye and after sometime, the left out part or the capsule of the lens can get thickened causing cloudy vision again. But this could be treated by laser. However with advanced technology, artificial lenses are now used to prevent this complication.

Most often, following cataract surgery patients will have to use 'reading glasses' to improve near vision. This will be prescribed 4 to 6 weeks after the surgery.

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