Laser eye surgery is an umbrella term for several eye surgeries used to correct refractive errors (i.e., how your eye focuses light).The most common types of laser eye surgery include LASIK, PRK, LASEK and EpiLASIK.

Each of the four laser eye surgery procedures below uses the same special laser, called an "excimer" laser, to reshape the cornea. This is what corrects vision. But laser eye surgery can vary in the specifics of the procedure, the recovery time, which surgical instruments are used and your patient candidacy. You might be a better candidate for PRK, for instance, than for LASIK.

The right laser eye surgery
Your ophthalmologist should be able to determine from a comprehensive, laser-eye-surgery-specific eye exam which procedure is best for you. His recommendation will follow which procedure he thinks will give you the best possible outcome. Most patients achieve 20/20 or better vision after laser eye surgery.

1. LASIK

Laser in Situ Keratomileusis
LASIK is the most common laser eye surgery. LASIK starts with the creation of a thin flap in the cornea. Your surgeon uses a blade or a laser to make this flap. The laser is considered more desirable by some doctors because of its precision, such as fewer visually significant complications ; however, all-laser LASIK costs a bit more than LASIK that uses a blade. Once the flap is created, the excimer laser is used to reshape the cornea, which corrects the refractive error.

2. PRK

Photorefractive Keratectomy
PRK is the second most common type of laser eye surgery. PRK starts with the removal of a portion of surface of the cornea or epithelial tissue. There is therefore no need for flap creation, and the removed tissue grows back. Some patients prefer PRK because they don't want a corneal flap, and some patients are better candidates for PRK eye surgery than for LASIK (for instance, people with thin corneas). Once the epithelium is removed, a laser is used to reshape the cornea. The laser is the same (i.e., excimer) as the one used in LASIK.

3. LASEK

Laser Epithelial Keratomileusis
LASEK is similar to LASIK and PRK, but it starts with the application of alcohol to the corneal epithelium. This loosens the outermost corneal cells and allows the surgeon to move them out of the way, without removing them, for the laser procedure. After reshaping the stroma with the excimer laser , the surgeon can replace the sheet of epithelial cells and put a contact lens to let it heal.

LASEK can be a good option for patients with thin corneas.

4. Epi-LASIK

Epithelial Laser in Situ Keratomileusis
Epi-LASIK starts the way LASIK does, except the flap is thinner and made only of epithelial tissue. Once the flap is created, it is moved aside, just enough that the surgeon can reshape the stroma underneath with the excimer laser. The flap of epithelium is then replaced and covered with a contact-lens bandage to heal. Some consider Epi-LASIK a hybrid of LASIK and LASEK. Some surgeons believe Epi-LASIK is a good option because the flap exists only in the epithelium layer, and because there's no alcohol used during the procedure.

Where does laser eye surgery come from?
Laser eye surgery was made possible in the 1980s, when a new type of laser called the excimer laser was being used at an IBM research facility. By a stroke of genius, the researchers discovered that their laser could incise animal tissue precisely without leaving scar tissue. This led to the first surgical application of a laser on human tissue. Eye surgeons (aka ophthalmologists) were among the first to approached researchers to learn how they could use this new technology in laser eye surgeries.

After roughly a decade of clinical trials and improvements, laser eye surgeries such as LASIK and PRK started being approved around the world. By 2001, LASIK had become the world's most common elective surgery.

Who gets laser eye surgery?
Laser eye surgery is recommended for people aged 18 or older. Before age 18, the eye might still be changing. Even after age 18, the eye might change. It's important to have a record of stable vision for at least a year before having laser eye surgery. Some providers may require two or more years. Additional criteria must be met to be a candidate for laser eye surgery.

Only a trained professional can determine your candidacy for laser eye surgery and recommend the best procedure for you.

Op.Dr.Ahmet UMAY
Bristol University
Ophtalmology Section / UK

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