Almost one million Canadians have discarded their glasses and contact lenses, thanks to a surgical procedure that aims to correct permanently common vision impediments, including nearsightedness, farsightedness and astigmatism.

Laser refractive eye surgery has quickly become one of the world’s most widely performed elective surgeries, according to U.S.-based research firm Market Scope. In the past 12 years alone, more than 18 million people worldwide have undergone the procedure.

“It doesn’t sound like a big deal not ever to have to wear glasses or contact lenses again, but for some people it really is,” says Dr. Dean Smith, an ophthalmologist at TLC Laser Eye Centre in Mississauga, Ont. “To be reliant on those things can be a real hassle, especially because a lot of people can’t tolerate contact lenses after a while.”

Clear vision is dependent on the cornea (the clear layer covering the eye surface) and the lens (behind the pupil) focusing properly or “refracting” the light onto the retina, which is at the back of the eye. In order for the images to be in focus, the shape of the eye has to be just right — not too long, too flat or too steep.

“What laser eye surgery does is create a different curvature of the eye,” says Smith, who has performed more than 10,000 refractive surgeries to date. “The curvature of any surface determines its optical properties, the point at which it brings light into focus. So we are either flattening or steepening that curvature to correct the focusing of the eye, depending on whether it is nearsighted or farsighted.”

The most commonly used procedure is laser-assisted in situ keratomileusis (LASIK), in which a tiny “flap” is created on the top layer of the cornea through which the laser enters and reshapes the deeper layers of the cornea to correct the refraction.
The flap is then repositioned without stitches, allowing the tissue to heal naturally.

Because LASIK leaves the surface cell layer of the eye intact, patients usually experience visual recovery within one or two days. The original refractive laser eye procedure — photorefractive keratectomy, or PRK — involves reshaping the surface of the cornea, resulting in a longer recovery period.
Although rare, the procedure is still used in cases in which the patient’s cornea is too thin to perform LASIK.

As with any surgical procedure, LASIK has its risks. Smith estimates the chance of error in creating the flap in the cornea is less than one in 1,000, largely because of advances in laser eye surgery technology.
The most serious — but highly unusual — complication is infection, which is prevented by strict post-op checkups and antibacterial drops. Other easily treatable complications include inflammation, cell growth around the flap as it heals and any accidental eye injury that dislodges the flap before it has healed.

“LASIK is basically a permanent correction,” says Smith, adding two caveats:
“Sometimes during the healing period, some of the prescription creeps back in. If that happens, we do a touch-up procedure.”

According to the Ottawa-based Canadian Ophthalmological Society, approximately 10% of laser refractive eye surgery patients will need a second procedure to obtain the desired results.

The second possibility is that natural changes in the eye will occur several years after the procedure, resulting in a decline in vision. Still, Smith says, such cases are unusual: “Most people do get a permanent fix and they rarely have to have the procedure done again.”

Bear in mind that not everyone is an ideal candidate for this surgery. Smith turns away about 10% of those who contact him because they are not suitable, usually because their degree of near- or farsightedness is too severe. Other factors that preclude people from undergoing this surgery include eye conditions, such as glaucoma or cataracts, and unusual eye measurements or thinness of the cornea.
Patients with uncontrolled diabetes, collagen vascular disease or any condition that renders them “immunocompromised” are also ineligible for the procedure.

Most surgeons recommend patients wait until they are at least 18 to 20 years old to ensure that the shape of their eyes has stopped lengthening, as the shape of the eye changes in youth. As well, the candidate’s eye prescription should be stable to ensure optimal results.

The cost of most LASIK surgery is about $5,500, including pre-surgery and follow-up visits. Clinics that use less advanced technology may charge less. For example, some clinics use razors to create the flap; lasers are safer. And the procedure is not covered under provincial health plans.

@page_break@Individuals who are interested in the LASIK procedure should consult their optometrist for a referral to a reputable eye clinic. Smith recommends asking the following questions before proceeding:

> How long has the surgeon been practising the procedure?

> What type of technology does the surgeon use to create the flap?

> What types of problems are most common with the procedure?

> What are the risks?

> Does the cost include pre- and post-surgery checkups? IE