The LASIK Difference
Doctors have placed incisions in the cornea to treat nearsightedness, farsightedness and astigmatism for over 25 years. They began looking at lasers to improve the precision and predictability of altering the shape of the cornea in the early 1980s. Researchers found that the Excimer laser could remove tissue with up to 0.25 microns of accuracy. In its second decade of use, the technologically advanced Excimer laser has added a tremendous amount of precision, control and safety to the surgical correction of vision errors. Using this remarkable technology, the cornea is reshaped to conform to your glasses or contact lens prescription, thereby reducing or even eliminating a lifetime of dependence on corrective lenses for hundreds of thousands of Americans every year.
LASIK, or Laser in –Situ Keratomileusis offers a number of benefits over other forms of laser vision correction because it is performed under a protective layer of corneal tissue. As a result, there is less surface area to heal, less risk of scarring, less risk of corneal haze, less postoperative discomfort, less postoperative need for medications, and vision returns more rapidly, often within a day or so. LASIK can also treat a higher range of vision errors. Although postoperative results vary, most patients are able to pass a drivers’ license test without their glasses or contact lenses.
After your eye has been completely numbed using “eye drop” anesthesia, an eyelid holder will be placed between your eyelids to prevent you from blinking.
Next, an instrument known as a microkeratome makes a protective flap in the cornea. During this process you may feel a little pressure, but no discomfort. You will be asked to look directly at a target light while the laser reshapes the cornea, usually in less than a minute. Then, the protective flap is folded back in place where it bonds securely without the need for stitches. After LASIK, some patients report a slight discomfort that usually goes away within twelve to twenty-four hours.
Step 1: Corneal flap is created with a microkerotome.
Step 2: The corneal flap is folded back.
Step 3: Excimer laser beam reshapes the cornea.
Step 4: The corneal flap is folded back in place.
How It Works
To treat nearsightedness, the cornea must be made flatter. This is accomplished by removing tissue from the center of the cornea.
To treat farsightedness, the central corneal must be made steeper. This is accomplished by directing the laser beam to remove tissue from around this area.
To treat astigmatism, the cornea must be made more spherical. By changing the pattern of the beam, tissue is removed in one direction more than the other.
Mypia or nearsightedness occurs when light rays are focused in front of the retina instead of directly on the retina.
Hyperopia or farsightedness occurs when light rays are not bent enough to focus on the retina.
Regular astigmatism occurs when light rays are focused at more than one point on the retina.
LASIK (Laser in-Situ Keratomileusis)
The Excimer laser removes microscopic layers of corneal tissue to change its shape, allowing light rays to focus directly on the retina.