The only way to cure nearsightedness is to operate on the eye, most ophthalmologists agree. What they can't agree on, however, is whether any of the currently available operations are any good.
The biggest objection to myopia surgery is that the risk-benefit equation is woefully lopsided. Myopia is, after all, a relatively benign condition that almost always can be corrected with glasses or contact lenses. At what cost should a surgeon try to repair a myopic eye? Is it really worth the risk of scarring, infecting or even blinding a perfectly good eye just so the myope can shed his glasses?
"My attitude toward myopia is tempered by the other things I see," says Harvard ophthalmologist Dr. George Garcia. In the context of the tragedies he encounters daily, Garcia says, it's hard to summon much sympathy for "the myope whose vision corrects to 20/15 with glasses or contacts . His nearsightedness has no influence on his future life; there are no longer things a myope cannot do."
For those who believe myopia is serious enough -- or glasses are inconvenient enough -- to warrant surgical intervention, these options are now available:
*Radial keratotomy. This operation, in which the surgeon uses a diamond knife to make eight or 16 tiny spoke-like incisions on the cornea, like cutting a pie, was developed in the Soviet Union and has been used on more than 100,000 patients in this country since 1978. The slits help flatten the cornea, which in turn reduces the optical strength of the eye and allows the distant image to focus correctly on the cornea.
Surgeons in the United States say that 85 percent of their patients treated with radial keratotomy have had a total reversal of nearsightedness, and another 15 percent have experienced a significant reduction in the strength of the corrective lenses they need. But the long-term results are not known.
Investigators for the National Eye Institute are engaged in a five-year study designed to answer that question. According to Dr. George O. Waring III, an Emory University ophthalmologist and coordinator of the study, the initial results are "encouraging" but the final vision results are "not precisely predictable for an individual patient." Thirty percent of patients remained somewhat nearsighted after surgery, and 10 percent became farsighted. Others have experienced a fluctuation in their vision during the day.
In general, the less severe the myopia before surgery, the better the results.
*Keratomileusis. Like radial keratotomy, keratomileusis surgically changes the shape of the cornea. In this procedure, developed in Bogata, Colombia, a slice of the cornea, about three-quarters of its thickness, is removed and frozen so it is firm enough to work with. Then it is placed on a special lathe and ground into a flatter shape to refocus the light just as if it were a plastic contact lense. Once reshaped, the cornea is defrosted and sutured back onto the eye.
Keratomileusis has not been as widely used as as radial keratotomy, in part because it is technically difficult to perform and few American surgeons have the necessary training or equipment.
*Epikeratophakia. An adaptation of keratomileusis, this technique involves the use of donor corneas from an eye bank. The donated cornea is frozen and ground to specifications, just as with keratomileusis. A circular grove is cut in the patient's cornea so the donor cornea can be sewn in place.
The advantage of this "living contact lens" is that if something goes wrong, the attached cornea can be removed and another cornea ground and reattached.
This technique can correct both nearsightedness and farsightedness, and can be used to correct the vision of both babies and older adults who have their lenses removed because of cataracts.