Epi-LASIK Eye Surgery: How It Works
Epi-LASIK is a newer laser eye surgery procedure that was developed to solve some of the potential problems with LASIK and LASEK. It's somewhat of a cross between the two, but differs in a few key areas.
During LASIK, your surgeon cuts a flap in the cornea with a sharp blade or a laser. But this procedure carries the risk of cutting the flap too thickly, although recently developed technologies such as bladeless LASIK (IntraLase) have helped reduce that risk.
LASEK involves cutting the cornea's outer layer, the epithelium, in a thin sheet that retains its hinge on the eye. This is done in Epi-LASIK too, but the surgeon uses a blunt, plastic oscillating blade instead of LASEK's finer blade.
Also, instead of the alcohol that's used in LASEK to loosen the epithelial sheet, in Epi-LASIK the surgeon typically uses the plastic blade, called an epithelial separator, to separate the sheet from the eye. This avoids the possibility of a reaction from the alcohol, which can kill epithelial cells.
However, the Journal of Refractive Surgery (January 2008) reports that some eye surgeons now do incorporate use of alcohol with the Epi-LASIK procedure to improve quality of the flap and attached hinge. Also, the study noted that use of the alcohol did not increase pain or haze after surgery.
Because it is more difficult to create the epithelial flap in people with steeper corneas and higher amounts of myopia, the procedure is more appropriate for people with flatter corneas and less myopia.
After the epithelial flap is made, it is lifted and gently folded out of the way. An excimer laser is used, as in LASIK or PRK, to sculpt the underlying corneal tissue. Then the epithelial flap is placed back on the eye with a kind of spatula.
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A special contact lens is placed on the eye to keep the flap in place while the epithelium grows back. Surgeons use a high-Dk contact lens for this, which means it is very oxygen-permeable. The contact lens protects the surface of the eye and allows the epithelial cells to grow back properly.
By about the third day after surgery re-epithelialization has occurred, so the doctor may permit you to remove the contact lenses.
Your vision probably will not be perfect immediately: In three days many patients do have 20/40 or even 20/20 vision, but others take longer possibly three or six months to reach their final result. Usually you can drive within a week after surgery.
These recovery times are significantly longer than with LASIK, which usually allows people to achieve good vision from the same day up to a few weeks later and to drive by the day after surgery.
As with any laser eye surgery, after Epi-LASIK it is very important to follow your surgeon's instructions exactly, because the quality of the final vision you achieve is affected by how well your corneas heal. Don't neglect to use the eye drops or other medications your doctor prescribes, and don't miss any follow-up appointments.
Who Can Have Epi-LASIK
If you are considering LASIK, but your doctor says you need Epi-LASIK instead, ask why.
It's not for everyone, but many surgeons who perform Epi-LASIK consider it a better option than LASIK for some patients. These include people who have thin corneas, with insufficient tissue for a good LASIK flap.
Epi-LASIK also may be safer than LASIK for people who have professions or hobbies that increase the chance of being hit in the eye (such as soldiers, police officers, boxers and racquet sports enthusiasts) because there's no risk of the flap being dislodged.
If you have Epi-LASIK, you will likely experience some discomfort after the procedure. This is usually manageable with over-the-counter painkillers. The discomfort after Epi-LASIK is reportedly less than that experienced after PRK or LASEK.
Diane Donofrio Angelucci also contributed to this article.
[Page updated May 2016]