News from the University of Arkansas for Medical Sciences 

Refractive Eye Surgery:
Shedding New Light on Old Eye Problems

In a normal eye, light rays focus on the retina. However, in nearsightedness, light rays fall in front of the retina.

DEC. 18, 2000 | The benefits are clear: Waking up in the morning and seeing the alarm clock clearly. Going to the theater and seeing a movie clearly. Playing sports with your children and seeing the ball clearly.

If you are nearsighted, farsighted or suffer from astigmatism, you may be a candidate for a type of refractive eye surgery now being offered in Arkansas exclusively at the Harvey and Bernice Jones Eye Institute at University of Arkansas for Medical Sciences (UAMS) Medical Center. Using the facility's new Nidek EC-5000 Refractive Laser System, ophthalmic surgeons can significantly decrease the patient's need for eyeglasses or contact lenses.

"The Nidek laser is a cool, ultraviolet beam of light," said Vahid Feiz, M.D., a UAMS Medical Center/Jones Eye Institute ophthalmic surgeon who subspecializes in corneal disorders. "The Food and Drug Administration has approved it for use in refractive eye surgery in nearsighted and astigmatic patients and will soon approve it for farsighted patients. The Nidek's technology is slightly different from other lasers used for this surgery. It has greater accuracy because it can remove the corneal tissue more smoothly and evenly. Within one to four days after surgery with the Nidek laser, more than 90 percent of patients have 20/20 vision."

According to Dr. Feiz, light enters the eye through the cornea (the transparent tissue over the front of the eye). The cornea focuses (or refracts) light through the lens and onto the retina at the back of the eye. The retina then converts the light rays into electrical impulses, which the optic nerve carries to the brain where they are recognized as images.

However, when the cornea and the lens do not focus the light precisely onto the retina, a refractive error occurs. In nearsightedness (or myopia), the light rays fall slightly in front of the retina because the eye is too long or the cornea is too steep. In farsightedness (or hyperopia), the light rays fall behind the retina because the eye is too short or the cornea is too flat. With astigmatism, an irregularly curved cornea or lens causes some, but not all, light rays to fall on the retina -- resulting in blurry visual images.

Jones Eye Institute physicians determine if a patient is a good candidate for refractive eye surgery by performing a brief, free screening to check the person's vision and glasses or contacts. If most likely eligible, the patient undergoes a more thorough assessment that includes corneal examination and mapping (to determine corneal shape and elevation) and retinal dilation and examination (to check for eye diseases and irregularities that might predispose the patient to retinal problems). In general, this surgery is not recommended for those who are under 18 years of age; are pregnant; have an eye disease, severe diabetes or an autoimmune disease; have not had a stable prescription for glasses or contacts for at least one year; and are not within the appropriate refractive error range for the procedure to be effective.

Refractive eye surgery is an outpatient procedure that employs anesthetic eyedrops and takes about 15 minutes per eye. "We start by using an extremely accurate instrument called a microkeratome to create a wafer-thin flap on the surface of the patient's cornea," Feiz explained. "Then, lifting this flap and using the Nidek laser, we gently remove microscopic amounts of corneal tissue to reshape the cornea so that it focuses light directly onto the retina. Afterward, we return the flap to its original position, and it self-adheres to the underlying cornea. This procedure requires no stitches, and the edge around the flap heals quickly."

Patients experience blurry vision during the first day after surgery. Most also experience "halos" (or night glare), which usually disappear about four weeks after the operation. Follow-up care includes undergoing routine exams over a one-year period, using antibiotic/steroid eyedrops to prevent infection during the first week, wearing plastic eyeshields to protect the eyes and facilitate healing during the first week, and using artificial teardrops to alleviate discomfort during the first 10 days.

In about 4 percent of refractive eye surgery cases -- usually the patients who are very young, very nearsighted or very farsighted -- overcorrection or undercorrection of vision occurs. These conditions can be remedied with "touch-up" surgery three months after the original procedure. However, even with additional surgery, some patients still have to wear weak glasses or contacts.

Less than 1 percent of patients develop minor infection after surgery; this can be treated with antibiotics. Just as rare is loss of vision in which postoperative vision is better than preoperative vision without glasses or contacts, but is not as good as preoperative vision with glasses or contacts. Treatment of this condition depends on the specific cause of each patient's loss of vision.

For more information about refractive eye surgery at UAMS Medical Center, call 501-686-5150. To schedule an appointment with an ophthalmologist, call 501-686-5822.

Carolyn M. Riggan

Links in this Article

Jones Eye Institute: www.uams.edu/jei/home.htm

08/09/02