Refractive Surgery: Defining Rupture Risks

People who are nearsighted (myopic) and are active in certain sports should use caution when considering radial keratotomy (RK) as a way to free themselves of glasses or contact lenses. Some ophthalmologists are suggesting that participants in contact sports or activities involving projectiles strongly consider photorefractive keratectomy (PRK), a laser procedure that was approved by the US Food and Drug Administration (FDA) last fall.

During RK, spokelike incisions are made around a central clear area of the cornea to flatten the cornea, changing the eye's refractive power. Research suggests that RK may weaken the cornea, thus making the eye susceptible to rupture and serious injury after blunt trauma. In one study (1), researchers concluded that RK "renders the cornea susceptible to blunt traumatic rupture from the intrinsic weakness of the keratotomy wounds up to 91 months after the operation." In a recent review (2) of 28 cases of traumatic globe rupture after RK, researchers reported that the injury occurred up to 10 years after a patient underwent surgery. The causes of injury were activities of daily living (12), assault (7), motor vehicle accident (5), and sports (4).

During PRK, the ophthalmologist, guided by a computer program, uses an excimer laser to reshape the cornea, changing the refractive power of the eye. PRK is less invasive and more precise than RK. A recent study (3) suggests that PRK does not weaken the eye.

RK was introduced in the US in 1978, and more than 1.5 million people have undergone the procedure. Patients who have RK should be routinely advised to wear protective polycarbonate eye-wear during contact sports or activities that involve the use of a projectile.

PRK, which has been used in Canada, South America, and Europe for several years, is quickly becoming available in many US urban areas since its approval by the FDA last fall. Many ophthalmologists in the US have become certified to perform PRK.

Most ophthalmologists agree on the relative benefits of PRK for active people. "In any contact sport—say basketball, where there are elbows and fingers going everywhere—people who have had RK are more susceptible to serious injury, because they have a weakened eye," says Bruce M. Zagelbaum, MD, an ophthalmologist affiliated with North Shore University Hospital in Manhasset, New York. He is also a clinical instructor of ophthalmology at Cornell University Medical College in New York City and an editorial board member of The Physician and Sportsmedicine.

"I feel laser is the way to go," says John B. Jeffers, MD, director of emergency service at Wills Eye Hospital in Philadelphia. "What we don't know is how much the cornea weakens with PRK, but the eye certainly is not weakened as much as with RK in which the cuts have to be 90% of the depth of the cornea," he says.

RK and PRK have comparable side effects (table 1), and studies have shown that the predictability of outcome is about the same for both, says Zagelbaum, who is also team ophthalmologist for the Department of Athletics at St John's University in Jamaica, New York, and principal investigator on eye trauma studies involving the National Basketball Association (NBA) and Major League Baseball. At this point, he says the big obstacle to PRK is price: RK runs about $750 to $1,800 per eye, while PRK runs about $2,000 to $2,500 per eye. Neither procedure is reimbursable by insurance companies since they are considered cosmetic. Availability is another problem, he says. "The ophthalmologist has to be properly trained in using the excimer laser, then they have to have access to one. The laser itself is expensive, $500,000—and then there are service contracts, which are very expensive."

Table 1. Potential Complications of Radial Keratotomy and Photorefractive Keratectomy

Radial Keratotomy Cataract formation from accidental surgical laceration Endophthalmitis Fluctuating vision Light sensitivity Overcorrection Seeing halos or star bursts around lights Traumatic rupture at incision scars Undercorrection Photorefractive Keratectomy Decentered ablations Halos around lights Loss of contrast sensitivity Overcorrection Postoperative corneal haze Sterile corneal infiltrates Undercorrection

Jeffers, who is team ophthalmologist for the Philadelphia 76ers of the NBA and the Philadelphia Eagles of the National Football League, still fields many questions from athletes regarding RK. "I tell them it's fine as long as they're prepared to wear sports glasses. If they don't want to do that, I tell them to wait until they retire."

References

1. Lee BL, Manche EE, Glasgow BJ: Rupture of radial and arcuate keratotomy scars by blunt trauma 91 months after incisional keratotomy. Am J Opthalmol 1995;120(1):108-110
2. Vinger PF, Mieler WF, Oestreicher JH, et al: Ruptured globes following radial and hexagonal keratotomy surgery. Arch Ophthalmol 1996;114(2):129-134
3. Burnstein Y, Klapper D, Hersh PS: Experimental globe rupture after excimer laser photorefractive keratectomy. Arch Ophthalmol 1995;113(8):1056-1059

David Groves
Santa Monica, California

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