The latest technique in refractive surgery is LASIK, or Laser-Assisted-In-Situ Keratomilleusis. It is also known as the flap and zap technique. The procedure is used to correct nearsightedness, farsightedness and astigmatism. This procedure is considered investigational in the United States. The procedure begins with an incision made part way across the cornea with a machine called a microkeratome. This creates a flap that is laid back exposing the middle stromal tissue of the cornea. The excimer laser is used to alter the shape of the stromal layer. The flap is then repositioned. Since less than 10% of the corneal epithelium is traumatized during the procedure, epithelial healing is usually achieved within 48 hours. This allows the individual to return to most of their activities within a day or two. Once a procedure reserved for high refractive corrections, experienced and skilled refractive surgeons are making this their procedure of choice for most refractive corrections.
Photorefractive Keratectomy is a treatment that also uses an Excimer Laser to alter the curvature of the front surface of the eye thereby modifying the focus of the light inside the eye.
An Excimer Laser mixes and charges Argon and Fluoride gases to produce a cold ultraviolet laser beam. Each pulse from an Excimer Laser removes 35 millionths of an inch of eye tissue in 12 billionths of a second and is the single most precise laser found anywhere in the world.
The front surface of the eye, the cornea, is like a watch crystal in that it is transparent and very strong. The cornea has about 6 different layers, and one pass of the Excimer Laser can remove less than 1% of the corneal tissue thereby changing the corneal curvature. This change in curvature results in a permanent change in vision correction. Unlike LASIK, there is no corneal incision. The epithelial healing time is a little longer than LASIK. Depending on your eye condition this is an alternative choice that may be preferable for you.
Radial Kerototomy was a procedure that was developed by a Russian Ophthalmologist, Dr. Svyatoslav N. Fyodorov at the Moscow Institute of Clinical Eye Surgery in 1973. He observed that a pilot who had injured his cornea from cut glass experienced a reduction in nearsightedness. Radial Kerototomy implies that radial incisions are made into the "kera" or cornea, the clear, front surface of the eye. Specifically, a diamond tipped surgical knife is used to make a series of radial incisions into the cornea. These incisions weaken the peripheral cornea and allow the normal eye pressure to push the peripheral cornea outward, causing the corneal curvature to flatten.
A number of factors influence the results of RK including the number of cuts, how deep and how long. Other factors that influence the procedure and results are one's age, sex, corneal curvature, corneal thickness and individual variation in healing. Most typically one can expect the procedure to be completed in five to ten minutes, done under local anesthesia. The second eye is usually done days later. The eye is patched or a contact lens is applied overnight and removed by the surgeon the following day. Results are practically immediate. Patients usually return to work within a few days.
Of course there are risks and complications that need to be reviewed extensively before you agree to a procedure such as RK. Please contact our office if you are interested in a consultation.
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