In the normal eye the light rays as they enter the eye are bent in such a fashion that the light rays are focused on the retina to produce a clear image that is then transmitted to the brain through the optic nerve. The inability to do that is known as a refractive error. Currently the most popular ways to correct such a problem is through the use of glasses, contact lenses or what is now known as refractive surgery.

Nearsightedness

The most common condition that is treated with refractive surgery is nearsightedness or myopia. This is a condition usually associated with the eye being longer than normal or due to unusual curve of the front of the eye known as the cornea. This causes the objects that are seen at a distance to be focused in front of the retina leading to blurry vision. The retina is the light sensitive part of the eye that transmits the images to the brain.

Farsightedness

In this condition, the eye is usually shorter than normal. This causes the objects seen at a distance to be focused behind the retina.

Laser Correction for Nearsightedness

Excimer laser, also known as PRK, uses an excimer laser beam composed of ultraviolet light to reshape the cornea. The cornea is the window-like tissue that is at the front of the eye that starts the bending of the light rays so they properly focus on the retina. During the excimer laser procedure the lasers ultraviolet light removes a small amount of corneal tissue much less than the thickness of a human hair. The flattening of the cornea makes it possible for the light rays to be focused on the retina properly. Candidates for laser surgery should be at least 18 years old with a stable vision for about one year and healthy eyes. Laser surgery may reduce or eliminate your dependence on contact lenses and glasses.

Laser Correction for Farsightedness

The Excimer laser beam composed of ultraviolet light is used to remove a small amount of corneal tissue at the midperiphery. The central steepening of the cornea causes the light rays to be focused properly on the retina.

Intracorneal Implants

In Phase III FDA trials, 98% of patients achieved 20/40 vision or better and 78% saw 20/20. This procedure corrects only low degrees of myopia from -100 to -350 diopters. The surgery is reversible, with some corneal stromal scars usually falling outside the line of vision. Side effects reported included glare 9.7%, halos 11.9% and night vision problems 17.3 %

Surgical Results and Safety - PRK

In the FDA clinical studies, 94% of patients achieved visual results of 20/40 or better. This type of vision generally is sufficient enough in most states to obtain a driver’s license without any restrictions. Since the first sighted eye was done in 1987 hundreds of thousands of nearsighted patients had successful treatment using the photorefractive keratectomy. The FDA has approved this procedure for qualified patients. Surgical results can vary as well.

What To Expect The Day of Surgery- PRK

Generally the treatment is painless due to the use of anesthetics drops to numb your eye. Once you are seated in a reclining chair a speculum will be placed to keep your lids open. You will be asked to look at a fixating light and once the preparations are done the average laser time is about 15 seconds. You will go home shortly after the procedure is done.

Lasix

Lasix, which stands for laser insitu kerotmileusis, is a surgical procedure which first produces a corneal flap which is retracted and in that corneal bed the excimer laser procedure is performed to reshape the cornea. The advantage of the Lasix procedure is that it promotes a very rapid recovery of vision with minimal discomfort.

The surgical flap is performed using a microkeratone that is a very precise instrument that creates this very thin hinged flap from the cornea. The excimer laser is then used to reshape the cornea underneath this flap. Once the excimer laser procedure is terminated the flap is repositioned.

Safety Of Laser Correction

As with any surgical treatment despite the very high success rate there are risks involved. There are advantages and disadvantages to both PRK and Lasix procedures. Before deciding on a laser correction for nearsightedness or astigmatism you should have a complete eye examination and the risks and benefits of the laser procedure should be discussed before making an informed decision.