How It Works
LASIK is performed while the patient reclines under a surgical device called an excimer laser in an outpatient surgical suite.
First, the eye is numbed with a few drops of topical anesthetic. An eyelid holder is placed between the eyelids to keep them open and prevent the patient from blinking. A suction ring placed on the eye lifts and flattens the cornea and helps keep the eye from moving. The patient may feel pressure from the eyelid holder and suction ring, similar to a finger pressed firmly on the eyelid.
From the time the suction ring is put on the eye until it is removed, vision appears dim or goes black. Once the cornea is flattened, a hinged flap of corneal tissue is created using an automated microsurgical device, either a laser called a keratome, or an instrument called a microkeratome blade. This corneal flap is lifted and folded back. Then the excimer laser preprogrammed with the patient’s unique eye measurements is centered above the eye.
The surgeon checks that the laser is positioned correctly. The patient looks at a special pinpoint light, called a fixation or target light, while the excimer laser sculpts the corneal tissue. Then the surgeon places the flap back into position and smoothes the edges. The corneal flap sticks to the main cornea within two to five minutes, and stitches are not needed.
The patient should plan to have someone drive him or her home after the procedure and then take a nap or just relax. To help protect the cornea as it heals, the surgeon may place a transparent shield over the eye(s) to protect against accidental bumps and to remind the patient not to rub the eye(s). The patient may need to wear the shield only when sleeping. The surgeon will provide eye drops to help the eye heal and relieve dryness.
It may take three to six months after LASIK surgery for the improvements in a person’s vision to fully stabilize and any side effects to go away.
Risks and Side Effects
LASIK, like any surgery, has potential risks and complications that should be carefully considered. LASIK has now been performed with millions of patients in the United States for more than 10 years, and the overall complication rate is low, between 0.2 and 2 percent of all patients. Infection and inflammation are possibilities, as with any surgical procedure, and usually can be cleared up with medications.
Problems with the corneal flap after surgery sometimes make further treatment necessary. There is a chance, though small, that vision will not be as good after the surgery as before, even with glasses or contacts.
Some people experience side effects after LASIK that usually disappear over time. These side effects may include hazy or blurry vision; difficulty with night vision and/or driving at night; scratchiness, dryness and other symptoms of the condition called “dry eye”; glare, halos or starbursts around lights; light sensitivity; discomfort or pain; or small pink or red patches on the white of the eye. In a small minority of patients, some of these effects may be permanent.
Sometimes a second surgery, called a retreatment, may be needed to achieve the desired vision correction. This is more likely for people who were more nearsighted, farsighted, or had higher astigmatism before LASIK -- those whose vision originally needed more intensive correction. Approximately 10.5 percent of LASIK patients in the United States require a retreatment.
> Questions to ask when considering LASIK
Some of this information is used with permission from the EyeCare America Web site: www.eyecareamerica.org/eyecare/treatment/lasik/index.cfm. Accessed April 9, 2008.
Last reviewed and updated in February 2009,
by the American Academy of Ophthalmology.
