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LASIK Laser Eye Surgery for Laser Vision Correction

Reviewed by Leslie Doctor, M.D.

LASIK Eye Surgery or LASIK is an abbreviation for “Laser Assisted In Situ Keratomileusis”, which is a type of Laser Eye Surgery that is performed to correct nearsightedness, farsightedness and astigmatism for patients who wish to decease their dependence or possibly even eliminate their dependence of eyeglasses and contact lenses for seeing things at a distance. LASIK Eye Surgery is the most common type of Laser Eye Surgery for correcting these types of vision problems. LASIK was first performed in 1989 by an Ophthalmologist in Greece and was introduced to American LASIK surgeons in 1990. Each year, many hundreds of thousands of LASIK Surgery procedures are performed in the United States. When performed by an experienced LASIK surgeon after a thorough examination, consultation and careful set of pretreatment diagnostic testing procedures, LASIK Eye Surgery has been found to be safe, effective and predictable. For healthy patients with stable prescriptions and "normal" eye anatomy and shape who are free from eye conditions and eye problems that can affect the result, LASIK Surgery has become the Laser Eye Surgery treatment of choice for correcting nearsightedness, farsightedness and astigmatism. The popularity and patient preference for LASIK is the result of two "patient friendly" characteristics of LASIK Eye Surgery.

First, LASIK Surgery is a type of procedure called a "lamellar" surgery. That is, it is performed "between the layers" of the cornea. By not disrupting the outermost optical surface of the cornea during the treatment, LASIK Eye Surgery produces a quick visual recovery. Depending on their prescriptions, the majority patients having LASIK are able to pass a drivers vision test (20/40) without correction on the day after their treatment. Most patients are easily able to return to work and almost all routine daily activities, including work, within a day or so.

Second, because the outermost layer of the cornea remains intact during and after the LASIK Surgery, there is minimal if any significant discomfort. Most patients experience a sandy or gritty sensation for a day or so after treatment, however there is rarely more than mild awareness and sensation.

LASIK Eye Surgery is performed essentially as follows:

To begin your LASIK procedure a staff member will place a series of eye drops in your eyes to make them numb so that you do not feel any discomfort during your LASIK surgery.

The LASIK Surgeon will then use either a specialized highly precise instument or a laser to create a very fine layer through about one third of the front surface of the cornea. This makes a "flap" of clear tissue on the central part of the eye. The resulting "flap" is approximately 160 microns thick (about 1/3 the thickness of human hair) and about 9 millimeters in diameter (much wider than the pupil).

Once this flap is created, the physician gently folds the flap back, exposing the underlying cornea. This types of Laser Eye Surgery which is performed "between layers" of the cornea is called lamellar surgery. When the flap is folded back, it is then possible for the LASIK surgeon to apply the actual laser treatment to reshape the cornea. Prior to your treatment, the LASIK surgeon will have carefully reviewed the detailed measurements of your prescription, your corneal thickness, your pupil size, the shape of your cornea and your wavefront aberromtery measurements and prepared a LASIK surgery treatment plan from which the staff members will be able to accurately program the laser in order to achieve the desired correction of your vision.   

The excimer laser is then applied in a specific pattern that has been determined from your measurement data. The number of spots and the pattern of application are delivered under computer control and monitored by the LASIK surgeon so that the curvature of the cornea is altered to achieve the desired correction.

If you have had LASIK to correct myopia or nearsightedness, your corneal curvature will now be flatter-whereas if you have had LASIK to correct farsightedness or hyperopia, your corneal curvature will now be steeper. If you have had LASIK to correct astigmatism, your cornea will have two unequal curvatures in order to correct your vision.   

Upon completion of the laser aspect of the treatment, the flap is gently laid back into its original position over the treated corneal tissue. Because the cornea has unique bonding qualities, the flap will simply adhere to the underlying surface without the need for stitches.
After the flap is gently laid back, the cross-section view of the cornea, treated for myopia, shows the reduced (flatter) corneal curvature (exaggerated for clarity).

Upon completion of the treatment, an eye shield may be applied. The patient goes home with a mild "something in the eye" feeling, comes back the next day to have the shield removed, and might have excellent vision immediately.  

LASIK has proven to be a safe and effective method of laser eye surgery as recently published in the British Journal of Ophthalmology by Ophthalmologist Professor Michael O'Keeffe reporting the results of a long term study commenced in 1998 and 1999 whereby LASIK patients were followed for a period of 5 years. Dr. O'Keeffe and his coauthors concluded that LASIK produced good unaided visual acuity results with an "excellent safety profile". The authors also referenced that "better laser nomograms, safer microkeratomes, larger optical zones and improved understanding of aberrations and their significance will lead to improvements in outcomes in the future". Today, patients considering LASIK surgery should be pleased to know that each of the areas referenced by Dr. O'Keeffe has been addressed by advances in technology are standard of practice among experienced LASIK surgeons.

Additional information about LASIK can be obtained from the Food and Drug Administration

Updates & News About LASIK Surgery & Vision Correction

FDA Panel Reviews LASIK Patient Satisfaction

Other Articles of Interest About LASIK, & Laser Eye Surgery for Laser Vision Correction
About LASIK Surgery About LASIK Enhancements
About Epi-LASIK About LASIK Laser Technology
About Bladeless LASIK About LASIK Laser Advances
About Custom Wavefront LASIK Find Top LASIK Specialists

©2011 The Medical Management Services Group

updated 4/26/12