Am Fam Physician. 2001;64(7):1193-1194
What is refractive surgery?
Refractive surgery is an alternative to wearing glasses or contact lenses. It can correct nearsightedness, farsightedness and astigmatism. The different kinds of surgeries are explained below.
Who gets refractive surgery?
People with nearsightedness, farsightedness and astigmatism can have refractive surgery.
Nearsightedness (also called myopia) is the most common type of vision problem. If you are nearsighted, near objects are clearer than distant objects.
Farsightedness (also called hyperopia) is another kind of vision problem. If you are farsighted, distant objects are clearer than near objects.
Astigmatism is an irregular curve of the cornea. Both nearsighted and farsighted people can have astigmatism. If you have astigmatism, objects are blurry at any distance.
What are the different kinds of refractive surgery?
Radial Keratotomy (RK)
This surgery is used to correct mild-to-moderate nearsightedness and has good results. The surgeon makes deep cuts like the spokes of a wheel in the cornea to flatten the central part. RK permanently weakens the cornea and is rarely done now that newer surgeries are available.
Photorefractive Keratectomy (PRK)
During this surgery, the surgeon uses a laser to reshape the surface of the cornea. This is done after removing thin layers of tissue from the surface of the cornea. The surface then takes up to one week to heal over the treated part of the cornea. Patients who have PRK done may have more pain and slower recovery than from other kinds of refractive surgery. Sometimes the eye heals more slowly. On the other hand, PRK has good results and is safe.
Laser-Assisted In Situ Keratomileusis (LASIK)
LASIK is a combined surgical and laser surgery. The surgeon creates a thin flap on the cornea with a special tool. The flap is folded back, and a laser is used to remove a precise amount of corneal tissue. The flap is then placed back down and allowed to heal. No stitches are necessary. Pain is usually minimal and your vision recovers faster than after PRK, but there is additional surgical risk involved in creating the LASIK flap.
Corneal Ring Segments (INTACS)
INTACS are crescent-shaped plastic ring segments. The surgeon places them in the eye to flatten the cornea. This is the only procedure that can be reversed. INTACS has excellent short-term results, but the long-term safety is not yet known. This surgery can be performed on people who have a low amount of nearsightedness and no astigmatism.
Are PRK and LASIK right for me?
You should be at least 18 years of age.
Your eyeglass or contact lens prescription should be stable for at least one year. Your prescription must be within certain limits, as determined by your ophthalmologist.
Your eyes must be healthy.
You should not be pregnant or nursing.
You should not have medical illnesses that affect the eyes, like diabetes, rheumatoid arthritis, lupus or glaucoma.
What should I think about before I decide to have refractive surgery?
Refractive surgery is done on a very delicate part of the eye. As with any surgery, there are risks and possible complications (see below). Refractive surgery may not give you perfect vision. Seven of 10 patients get 20/20 vision as a result of the surgery and you may still need glasses or contact lenses even after surgery. If you have refractive surgery to correct your distance vision, you will probably still need to use reading glasses when you are about 45. Refractive surgery is new, and we do not know all the long-term effects. Refractive surgery cannot be reversed. INTACS can be removed. Most health insurance plans do not cover refractive surgery. You may need more surgery, called enhancements, to get the best possible vision.
What are the risks and possible complications?
Overcorrection or undercorrection—in other words, the surgery may change your eyes too much (overcorrection) or not enough (undercorrection). If this happens, your vision can often be improved with glasses, contact lenses or enhancement surgery.
Scarring of the cornea and irregular astigmatism (permanent warping of the cornea)—this may make you unable to wear contact lenses.
Infection of the cornea.
Loss of vision—you might not be able to see as well after surgery, even with glasses or contact lenses, as you did with glasses or contact lenses before surgery.
A decrease in contrast sensitivity or sharpness—this means that even though you may have 20/20 vision, objects may appear fuzzy or grayish.
Problems with night driving—you may need glasses to correct this.
What are the possible side effects of the surgery?
Eye discomfort or pain
Hazy or blurry vision
“Scratchy” eyes
Dry eyes
Glare
Haloes or starbursts around lights
Light sensitivity
Small pink or red patches on the white of the eye
Your doctor can help you decide if refractive surgery is right for you. If you are happy wearing contact lenses or glasses, you may not want to have refractive surgery.
Where can I get more information about these eye surgeries?
You can contact the following groups for more information:
American Academy of Ophthalmology
P.O. Box 7424
San Francisco, CA 94120–7424
Web address:http://www.aao.org
American Society of Cataract and Refractive Surgery
4000 Legato Road, Suite 850
Fairfax, VA 22033
Web address:http://www.ascrs.org
International Society of Refractive Surgery
1180 Springs Centre South Blvd., Suite 116
Altamonte Springs, FL 32714
Web address:http//www.isrs.org