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LASIK eye surgery

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Illustrations

Lasik eye surgery - series
Lasik eye surgery - series

Alternative Names    Return to top

Laser-Assisted In Situ Keratomileusis; Laser vision correction

Definition    Return to top

LASIK is a surgical procedure that can reduce a person's dependency on glasses or contact lenses. The procedure permanently changes the shape of the cornea (the delicate clear covering on the front of the eye). For clear vision, the eye's cornea and lens must bend (refract) light rays properly, so that images are focused on the retina. If the light rays aren't clearly focused on the retina, the images you see are blurry.

This blurriness is referred to as a "refractive error." It is caused by an imperfectly shaped eyeball, cornea, or lens. LASIK uses an Excimer Laser (an ultraviolet laser) to precisely remove corneal tissue to correct the shape for better focusing.

LASIK eye surgery is performed most often on people who have nearsightedness (myopia), which means that they only clearly see nearby objects; anything far away is blurry.

Description    Return to top

A complete eye examination will be done before surgery to make sure your eyes are healthy. Once this is determined, the doctor will measure the curve of the cornea and the size and position of the pupils, the shape of the eyes (making sure there are no irregularities that would prevent LASIK as an option), and the thickness of the cornea (making sure there will be enough tissue left, once the cornea is cut and reshaped).

A signed informed consent form is needed before the procedure, confirming knowledge of the risks, benefits, alternative options, and possible complications.

LASIK is an outpatient surgical procedure and will take 10 to 15 minutes for each eye.

The only anesthetic used is an eye drop that numbs the surface of the eye. The procedure is done with the person awake. LASIK may be done on one or both eyes during the same session.

During LASIK, a special knife (a microkeratome) is used to cut a hinged flap of corneal tissue off the outer layer of the eyeball. The flap is lifted out of the way and a special laser is used to reshape the underlying corneal tissue.

The calculation for how much tissue is removed by the laser is done ahead of time. Once the reshaping is done, the surgeon replaces and secures the flap. No stitches are needed. An eye shield or patch will be placed over the eye to protect the flap and to help prevent rubbing or pressure on the eye until it has had enough time to heal.

Why the Procedure is Performed    Return to top

LASIK is done most often on people who use glasses or contact lenses because of myopia (nearsightedness). It is occasionally used to correct farsightedness. It may also correct astigmatism.

The FDA has approved the Excimer Laser to correct nearsightedness up to -12.00D with -4.00D of astigmatism, and farsightedness from +1.00 to +6.00 with 1.00D of astigmatism. (Diopter, symbol D, is the measurement of the refractive error. A negative D value indicates nearsightedness and a positive D value indicates farsightedness.)

The FDA, in cooperation with the American Academy of Ophthalmology, has developed the following guidelines and recommendations for good candidates for LASIK:

Risks    Return to top

Outlook (Prognosis)    Return to top

Immediately following the surgery, there may be a sense of burning, itching, or a feeling that something is in the eye. There may be mild discomfort for which the doctor may prescribe a mild pain reliever medication. It is very important NOT to rub the eye after LASIK, so that the flap does not dislodge or move.

The day of surgery, vision generally is blurry or hazy but by the next day the blurriness improves. The doctor should be called immediately if there is severe pain or any of the symptoms worsen BEFORE your scheduled follow-up appointment (24-48 hours after surgery).

At the first doctor visit after the surgery, the eye shield will be removed and the doctor will examine your eye and test your vision. You may receive eye drops to help prevent infection. Do not drive until your vision has improved enough to safely do so.

Other things to avoid include swimming, hot tubs, whirlpools, contact sports, lotions, cremes, and eye make-up for between 2-4 weeks after surgery. The doctor will give you specific instructions.

Recovery    Return to top

References    Return to top

Yanoff M, Duker JS, Augsburger JJ, et al. eds. Ophthalmology. 2nd ed. St. Louis, Mo: Mosby; 2004:188-195.

Duffey RJ, Leaming D. US trends in refractive surgery: 2003 ISRS/AAO survey. J Refract Surg. 2005 Jan-Feb;21(1):87-91.

Cobp-Soriano R, Calvo MA, Beltran J, Llovet FL, Baviera J. J Cataract Refract Surg. 2005 Jul;31(7):1357-65.IG.Thin flap laser in situ keratomileusis: analysis of contrast sensitivity, visual, and refractive outcomes.

Balazsi G, Mullie M, Lasswell L, Lee PA, Duh YJ. Laser in situ keratomileusis with a scanning excimer laser for the correction of low to moderate myopia with and without astigmatism. J Cataract Refract Surg 2001 Dec;27(12):1942-51.

Miller AE, McCulley JP, Bowman RW, Cavanaugh HD, Wang XH. Patient satisfaction after LASIK for myopia. CLAO J 2001 Apr;27(2):84-8.

McGhee CN, Craig JP, Sachdev N, Weed KH, Brown AD. Functional, psychological and satisfaction outcomes of laser in situ keratomileusis for high myopia. J Cataract Refract Surg 2000 Apr;26(4):497-509.

Update Date: 8/17/2007

Updated by: Manju Subramanian, MD, Assistant Professor in Ophthalmology, Vitreoretinal Disease and Surgery, Boston University Eye Associates, Boston, MA. Review provided by VeriMed Healthcare Network.

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