Up until recently patients who had trouble seeing objects at distance or near would correct these conditions by wearing glasses and/or contacts. Surgical techniques known as Refractive Surgery are now a reasonable alternative which can reduce or eliminate the dependence on glasses or contact lenses.
Refractive problems are due to failure of the light to be properly focused on the retina, which is like the film of the camera. The vision is clear if the cornea and the lens inside your eye focus the image exactly on the retina. The retina is the inner layer of the eye that receives the visual information and transmits it to the brain. The vision is blurry if the visual image falls in front of the retina, this is known as Myopia or nearsightedness. If the cornea is oval shaped like a football then the image does not fall properly on the retina and is distorted. This is called astigmatism.
The traditional solution to these refractive problems is correction with glasses or contact lenses. Each of these has its benefits and disadvantages. Glasses can break and sometime shatter pieces of lens material around or into the eye.
Contact lenses are a foreign body that is placed on to the eye. They are not part of the evolutionary process. Many patients develop reactions to contact lenses for different reasons. It may be inflammation from the mechanical trauma of the contact lens rubbing up against the eye. Patients may develop allergies to contact lens solutions. Contact lenses pose the risk of infection, such as corneal ulcer.
Refractive Surgery is now becoming a reasonable alternative for some patients for the treatment of myopia and/or astigmatism.
Treatment of myopia involves re-shaping (flattening) of the cornea so that light rays entering the eye will focus directly on the retina. One method used today to flatten the cornea is by using excimer laser.
An IBM researcher first saw the potential for using a laser beam to re-contour the cornea by vaporizing precisely-measured microscopic amounts of the surface tissue. This procedure became known as photorefractive keratectomy or PRK. The first PRK procedure was carried out in Germany in 1988, since then more than 600,000 procedures have been carried out around the world. The vast majority of the patients are functioning without glasses or contact lenses.
"Photorefractive Keratectomy" (PRK): is a laser surgical procedure designed to change the shape of the cornea and thus correct the way the eye focuses on light. Using precise computer-controlled laser technology, small amounts of corneal tissue are removed with the pulse of the excimer laser. The central portion of the cornea is flattened reducing the amounts of myopia. The computer-controlled laser delivery system makes the procedure reproducible and free of surgeon variability.
Unlike Radial Keratotomy, which flattens the cornea by making, four to eight incisions, the laser procedure does not weaken the eye, and does not require a re-operation rate of as much as 40%. Reducing your dependency on glasses is a reasonable expectation. Patients between -1.00 to -7.00 diopters of myopia and less than 1.25 diopters of astigmatism have a better than 90% chance of achieving an uncorrected vision of at least 20/40 (drive a car without glasses). An uncorrected vision 20/20 is possible in more than 80% of these cases. As with any surgical procedure, individual risks cannot be guaranteed.
This procedure takes ten minutes from start to finish. This includes the training session to familiarize you with the laser target as well as the actual laser procedure (up to 36 seconds depending on your refractive error).
Laser surgery offers an alternative to glasses or contact lenses. Surgery, glasses, or contacts have their advantages and disadvantages. A complete eye examination is the best way to determine which method is best for your vision.
