SEATTLE, WA, January 31, 2009 /24-7PressRelease/ -- Advanced Surface Ablation (ASA) is a laser vision correction procedure for the treatment of nearsightedness, farsightedness and astigmatism. An excimer laser is used during the ASA procedure to remove tissue from the cornea, the clear front surface of the eye. Learn more about how the eye works.
Types of Refractive Errors
Nearsightedness and farsightedness are refractive errors that occur when the eye's refractive power (ability to bend light rays) does not match its focal length (distance front to back). The eye is bending light too much or too little to focus it on the retina at the back of the eye.
• If the individual is nearsighted, light focuses in front of the retina and causes distant objects to be blurry
• If the individual is farsighted, light focuses beyond the retina and causes near objects to be blurry
In astigmatism, the eye is shaped similar to a football, so that vision is blurry at all distances. The cornea is bending light in two ways at once: more sharply on its short curvature and less sharply on its long curvature. Astigmatism is more common in nearsighted individuals.
Presbyopia is a loss of close-up vision due to changes in the eye's lens. It occurs as the eyes age. Since Advanced Surface Ablation treats only the eye's surface tissue and not the lens, it is not suitable for presbyopia.
Treatment for Refractive Errors
Before laser vision correction procedures became widely available, eyeglasses and contact lenses were the standard treatment for nearsightedness, farsightedness, and astigmatism. In the 1990s, Radial Keratotomy (RK) treated nearsightedness and astigmatism. In this procedure, the cornea is flattened to shorten the eye's length and correct the refractive error. A handheld blade, not an excimer laser, was used to perform RK.
The introduction of LASIK, an acronym for Laser Assisted in situ Keratomileusis, was a vast improvement for treating nearsightedness, farsightedness and astigmatism. LASIK uses a microkeratome, an automated blade device that can create a very thin flap of tissue, called the corneal flap. A laser is then used to remove tiny amounts of corneal tissue from pre-planned locations. No sutures are needed and if retreatment is necessary, the corneal flap can be lifted again.
Qualifying for Advanced Surface Ablation
Advanced Surface Ablation (ASA) also uses the FDA-approved laser, and no surgical blades or incisions are needed. During the ASA procedure, the laser emits pulses of light and heat. Since the process uses ultraviolet light which is easily absorbed by the eye's surface, corneal tissue is vaporized using controlled heat, minimizing the risk of corneal scarring.
Good candidates for ASA have:
• A stable vision prescription for at least one year
• Normal sized pupils
• No corneal scarring
• No eye diseases or disorders, such as keratoconus, dry eyes, diabetes, glaucoma, cataracts or herpes of the eye
Additionally, ASA candidates cannot be pregnant or nursing or require a pacemaker for a heart condition.
In Seattle, Washington, Dr. Kent Leavitt of Bellevue Lasik and Cornea is available to answer your questions about ASA or other laser vision correction procedures.
Source: Bellevue Lasik and Cornea
Website: http://www.bellevue-lasik.com
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