Better Vision Is in Plain Sight

Imagine not having to grope blindly on your nightstand for your glasses first thing in the morning and saying goodbye forever to the daily ritual of cleaning your contact lenses.

"The best thing about having LASIK done is being able to read the clock on the wall when I open my eyes in the morning," says Joh Jung-min, 36, who recently had refractive surgery to correct nearsightedness.

Ms. Joh, who wore contact lenses for more than 20 years, threw away her last disposable lenses two months ago, joining legions of Koreans who have had the Laser-Assisted In Situ Keratomileusis surgery since it was introduced late in 1995. While no firm statistics are available on how many such operations have been performed in South Korea, more than 100,000 people are estimated to have had the LASIK surgery, which costs about 3 million won ($2,300) for both eyes. The operations have been carried out in nearly 200 eye clinics.

An excimer laser is used to change the shape of the cornea, the part of the eye that helps focus light to create an image on the retina. Usually, the shape of the cornea and the eye are not perfect and the image on the retina is blurred or distorted. There are three primary types of imperfections, or refractive errors, in the focusing power of the eyes: myopia (nearsightedness), hyperopia (farsightedness) and astigmatism (distortion of the image on the retina). In LASIK surgery, precise and controlled removal of corneal tissue reshapes the cornea, changing its focusing power.

A knife, called a microkeratome, is used to cut a flap in the cornea. A hinge is left at one end of this flap. The flap is folded back to reveal the stroma, the middle section of the cornea. Pulses from a computer-controlled laser vaporize a portion of the stroma, and the flap is replaced.

"The surgery on each eye takes about 10 minutes and even with the various pre-operative tests, which take about an hour, you can walk out of the clinic with improved vision in about 90 minutes," says Dr. Choi Woong-san, an ophthalmologist who runs the Purun Eye Clinic in Samseong-dong, Seoul.

In addition to the convenience, the procedure is relatively safe with complications occurring only in about 2 percent of patients, according to Dr. Choi. Problems include overcorrection or under-correction, corneal scarring or infection and problems with night driving.

Despite the promise of freedom from the inconveniences of glasses and contact lenses, LASIK surgery is not for everyone.

"About one person in 100 has to be turned a- way because they have conditions for which LASIK is not recommended," Dr. Choi explains.

It is not recommended if you have had to change the prescription for your contact lens or glasses within the last year. This is because of refractive instability. People 18 years or younger, people whose hormones are fluctuating due to disease or pregnancy, or people taking medication, such as steroids, that cause vision fluctuation, are more likely to have refractive instability and should not have the laser procedure.

The surgery is also not recommended for people who have a disease or who are on medication that may affect the healing of wounds.

Any history of herpes simplex or herpes zoster involving the area; glaucoma, suspected glaucoma or ocular hypertension; eye diseases or severe dry eyes, or eye injuries or previous eye surgery also makes you ineligible for LASIK.

Other risk factors include having large pupils or thin corneas. Younger people and people on certain medication may be prone to having large pupils under dim lighting conditions. This can cause symptoms such as glare, halos, starbursts, and ghost images after surgery. Having a thin cornea may result in blindness.

Also, LASIK surgery does not counter age-related eye decline. For example, if you have surgery to correct distance vision, you will still need reading glasses in your mid-40s.

Indeed, you should go into surgery with your eyes wide open, because the surgery is irreversible. Dr. Choi warns that thorough pre-operative tests are necessary to avoid complications after the surgery.

"Some people are in a great hurry to get the surgery done but tests are repeated two or three times to reduce the possibility of problems later on," he says. During a typical pre-operative screening, a series of examinations － including tests of corneal thickness, corneal topography, pupil size and refractive error － are conducted.

Although LASIK surgery improves vision most of the time, patients should have realistic expectations, Dr. Choi says.

"While 70 to 80 percent of those who had 20/20 vision with the aid of glasses or contact lenses will achieve 20/20 vision following LASIK surgery, only 30 to 40 percent of those who had high myopia before surgery can expect to have 20/20 vision after the surgery," he says.

by Kim Hoo-ran