Vision Correction Through Laser Eye Surgery
One of the most popular forms of laser eye surgery is LASIK, which stands for laser-assisted in situ keratomileusis. This type of eye surgery changes the cornea shape. The cornea is the clear membrane that stretches over your pupil and your iris (the colored part of your eye). After the surgery, the cornea should focus the light the way it should on your retina instead of on a point in front of or behind the retina, which is what causes either nearsightedness or farsightedness. If you want to consider eye surgery, your ophthalmologist will discuss several types of laser surgery with you. One type is PRK (PhotoRefractive Keratectomy). In PRK the top layer of the cornea, called the epithelium, is scraped away after which an excimer laser goes to work to reshape the tissue located on the surface beneath, called the stromal. After the surgery, the top layer has to grow back prolonging the recovery period. A second type is LASEK (Laser Assisted Sub-Epithelial Keratomileusis). This is an advanced form of PRK. It uses an alcohol solution to soften the epithelium so that it can be removed in one piece. After the stroma is reshaped to correct the vision, the epithelium is put back over the eye, which speeds up the healing process. A third type is Epi-LASEK. This is a modified version of LASEK using a "separator" to keep a living layer of epithelium in good shape while waiting to be replaced reshaping of the stroma. Its advantage is in reducing pain and recovery time even more than LASEK.
LASIK uses a microkeratome metal blade to make a physical cut to the cornea creating a flap. The excimer laser then reshapes the eye. After the reshaping, the flap is put back into position. This is does not create pain in most patients. The best advantage is that vision is corrected immediately. You may want to consider LASIK eye surgery if you are nearsighted (myopia), farsighted (hyperopia), or suffer from astigmatism. Nearsightedness is caused by the light rays focusing in front of the retina which causes blurring of distant vision. This will happen if the eyeball is too long or if the cornea is too curved. Farsightedness is caused by a short eyeball or a cornea that is not curved enough. These conditions will focus the light behind the retina blurring near vision. Astigmatism, messes up the focus of both near and distant vision because the cornea curves and flattens unevenly. Your eye doctor will probably recommend that you explore other forms of vision correction before you resort to LASIK eye surgery. Glasses or contact lenses, which will cost much less than surgery, are one option. Unlike diseases of the eye, cornea shape is not a progressive problem so it shouldn't get worse. Sometimes they actually improve as we age. Cataracts are never removed with laser eye surgery of any type. The clouded lens has to be physically removed and replaced with a lens implant. Although the operation is outpatient and takes only a few minutes to complete, it is not done through laser procedures. Discuss all of your options before deciding on any one vision correction procedure. |
