Laser way to normal sight

By Ayesha Inoon

If you need glasses or contact lenses to see clearly, the idea of a procedure that will restore your eyesight to normal may seem almost too good to be true. Laser eye surgery is used all over the world today for exactly this purpose. Relatively painless, and with a high success rate, the surgery has been performed in Sri Lanka for the past three years.

It is a safe, fast and extremely patient friendly procedure, says Dr. H. Palihakkara, Consultant Ophthalmologist, as he discusses the various aspects of LASIK in this interview with Mediscene.

What is LASIK?

LASIK (Laser In Situ Keratomileusis) is a surgical procedure intended to restore good vision to those dependent on glasses or contact lenses. This is done by altering the curvature of the cornea using a special laser.

The cornea is a part of the eye that helps focus light to create an image on the retina. The bending and focusing of light is also known as refraction.

Sometimes the shape of the cornea and the eye are not perfect and the image on the retina is blurred or distorted. These imperfections in the focusing power of the eye are called refractive errors.

There are three primary types of refractive errors: myopia (nearsightedness), hypermetropia (farsightedness) and astigmatism (distortion of the image on the retina caused by irregularities in the cornea or lens of the eye). LASIK may be used to treat all three conditions.

Two methods are used during surgery. In one, an instrument called a keratome is used to cut a flap in the cornea. A hinge is left at one end of this flap. The flap is folded back revealing a bare area called the stroma, the middle section of the cornea. This area is treated with the laser and the flap is then replaced.

In the second method a layer of corneal tissue is removed, the area treated with the laser, and left to grow back.

During the surgery the patient is asked to lie down and fix his gaze on a blinking red light.

An instrument will be used to keep the eyelids open. An eye tracker is used to focus on the iris of the patient's eye, which enables the laser to follow the eye if there is any slight movement of the head.

The entire procedure takes approximately half an hour, and does not require hospital admission.

What are the risks?

Like any other surgery, LASIK involves certain risks, but these can be greatly eliminated by careful pre-surgical preparation and post-surgical care. The main risk is that of infection and patients are usually asked to stay at home for at least a week after surgery to minimise this possibility.

There is a chance of over or under correction; however this is usually negligible enough to not require the use of glasses again.
Another risk is bulging of the cornea called corneal ectasia, which those with thin corneas are particularly susceptible to after surgery.

The refractive error returning in some measure, after some time, is also a rare possibility.

Is LASIK for you?

You are probably a good candidate for Laser Eye Surgery if you are over 18 years of age and have not had many changes in your prescription for glasses/contact lenses over the past few years. Doctors perform a thorough initial or baseline evaluation to determine if you are a suitable candidate for LASIK. You should tell your doctor about all past and present eye conditions as well as any other medications you may be taking.

Those who have eye disorders or any eye complications involving the cornea or retina such as cataracts or glaucoma cannot undergo LASIK. For those who have Dry Eye Syndrome, this must be treated before the surgery.

Those who have a condition called keratakonus, or a thin cornea are at risk of the cornea bulging later on, and are therefore not suited for LASIK.

It is not recommended for women who are pregnant, breastfeeding or on contraceptive pills. Those with diabetes may only go for LASIK if their blood sugar is well under control.

The deciding factor in choosing suitable candidates for surgery is the thickness of the cornea. A Corneal Topography System is used to assess the corneal conditions of the patient before surgery.

How do I prepare for LASIK?

For at least one week before surgery, you will be asked to clean your eyelids daily with diluted baby shampoo. If you use contact lenses, you must stop wearing them for at least two weeks prior to performing LASIK and at least for a month if they are hard lenses. Contact lenses change the shape of your cornea for up to several weeks after you have stopped using them, which can cause inaccurate correction during surgery. You should also avoid using any cosmetics the week prior to surgery.

How soon will I recover?

The eyes usually heal within 48 hours after the procedure. A transparent shield is placed over the eye at the end of the procedure as protection, to prevent you from rubbing your eye and putting pressure on your eye while you sleep, and to protect your eye from accidental collisions until the flap has healed. After 24 hours, for the next three days, the shield is only necessary when sleeping. Patients are able to continue with normal activities such as reading, writing, using the computer or watching television.

Staying indoors for at least a week will minimise the risk of infection. You must also use any eye-drops prescribed and carefully follow any other instructions given by the doctor.

You may be given artificial tears for up to three months after the surgery to prevent the occurrence of Dry Eye Syndrome.

Some patients complain of a gritty feeling in their eye soon after the surgery, but this usually passes within a day.

What does it cost?

At present LASIK costs approximately Rs.50,000 per eye and is available at Nawaloka Hospital.

Under the care of an experienced doctor, carefully screened candidates are likely to experience successful results with LASIK.