First LASIK – Now Super LASIK

What LASIK does

LASIK surgery uses a cool ultraviolet laser (called an excimer laser) to correct the shape of the cornea. This is the front surface of our eye, through which light rays pass on their way to the retina. They pass through the lens behind the cornea, and form a tiny image on the retina, which is transmitted to the brain by the optic nerve.

Imperfect corneal shape

When the cornea is not perfectly shaped, the light rays bend at the wrong angle. Then they don’t focus on the retina, but in front of it or behind it. This creates near- and far-sightedness respectively.

And when the cornea has little irregularities in its shape, the light rays come to the retina out of focus in certain areas, so that our vision has blurriness in different parts.

LASIK uses the excimer laser to vaporize tiny pieces of corneal tissue, so as to correct the corneal shape and surface. Then the light rays focus sharply on the retina and we see clearly.

Corneal flap

Before directing the laser beam on to the cornea to reshape it, the eye surgeon cuts a tiny flap on the corneal surface and bends it back to expose underlying tissue. The laser works on that tissue and the flap is replaced, where it heals itself in a few days.

Not everyone is a good candidate for LASIK

If your corneas are too thin or too flat, LASIK is not a good answer.

Corneas too thin

In LASIK, the little flap is cut with a device called a microkeratome. If your corneas are too thin, the eye surgeon may not be able to cut a good flap.

· In cutting it as thin as he can, he may inadvertently form it with a hole in it, so that some of what should be folded-back flap is still part of the cornea and will block the laser

· Alternatively, he may by mistake detach it altogether rather than folding it back. Then it may not heal as well.

· Or he may cut it too small in diameter for the laser to have enough area to work on.

Corneas too flat

The purpose of LASIK surgery is to remove tiny pieces of corneal tissue to improve vision. But if the cornea is too flat, removing more tissue will make it even flatter, and this won’t improve vision. So people with extra flat corneas are not good candidates for LASIK surgery.

LASEK (E-LASIK)

LASEK (Laser Epithelial Keratomileusis) uses a different tool to create the tiny flap. It’s called a trephine and has an even finer blade.

· The eye surgeon uses the trephine to partly create the flap

· Then he covers the eye with a mild alcohol solution for a half-minute or so to loosen the flap’s edges

· Finally, he uses a tiny hoe-like tool to lift the flap’s edges and fold it back out of the way
The LASEK procedure is then like traditional LASIK, using the excimer laser to remodel corneal tissue, and the flap is carefully replaced.

Afterwards

The flap usually heals in a day or two and you may feel some eye irritation during this time. Many patients wear a “bandage” contact lens which holds the flap in place while it heals, but also allows oxygen to flow to the eye tissue.

After a week or so you’ll have your new vision. This is a longer time than after LASIK, when the results are immediately noticeable.

If you’re not a candidate for LASIK, you may do very well indeed with LASEK instead. Your eye surgeon will be able to explain why one procedure would be better for you than the other.

Epi-LASIK

In Epi-LASIK, the small flap is cut and excimer laser used to vaporize excess corneal tissue, as in LASIK and LASEK.

But in Epi-LASIK, a plastic, oscillating blade is used to create the flap, rather than the microkeratome or the finer-bladed trephine.

And instead of using an alcohol solution to loosen the flap’s edges before lifting it back, a very fine plastic blade is used, called an epithelial separator. Why?

Because in some cases, the alcohol solution can cause epithelial cells to die. An epithelium is a surface membrane, so in this context, it refers to the surface cells on the cornea. The eye must grow more epithelial cells around the flap’s edges to reintegrate it with the rest of the corneal surface.

Epi-LASIK results

As with LASEK, vision improvement occurs more slowly than it does after LASIK. For some, it’s evident after 3 or 4 days, and for others it’s not for 3 or 4 months.

But before Epi-LASIK, people with thin corneas were not able to have laser vision correction. Now they often can.

A quality eye surgeon is key in achieving excellent results from any laser eye surgery. Choose your surgeon carefully, asking lots of questions and considering not just the relative fees, but what you’ll receive for those fees.