Another Step Closer to Comprehensive Vision Correction

BY JAMES V. AQUAVELLA, M.D.
JUNE 1997

The recent FDA approval of photorefractive keratectomy for nearsightedness with astigmatism (PRK-A) is a very important event for both patients and eyecare practitioners. Now contact lenses, spectacles, radial keratotomy, astigmatic keratotomy, laser in situ keratomileusis and excimer laser correction for myopia and astigmatism are all available, and our armamentarium continues to expand.

REFRACTIVE
SURGERY TOOLBOX

Interest in photorefractive keratectomy has been waning over the past several months. Discouraged by FDA limitations on PRK, doctors and patients have been directing their interests to various alternatives. Yet, we're seeing a significant reduction in the number of radial keratotomy cases with a very slow (although steady) increase in PRK.

Interest in LASIK has greatly increased, although the number of treatments being performed remains relatively small. Some refractive surgeons perform only LASIK, but most don't perform LASIK at all, generally because the procedure entails a much steeper learning curve than does PRK.

Astigmatic keratotomy has been used in conjunction with PRK to treat moderate astigmatism associated with myopia, but the incidence of this will probably decrease. Multizone/multipass techniques, whereby correction is accomplished through stages of ablations, and hyperopic correction are available throughout the world and clearly will be introduced into the U.S. market in the not-too-distant future. There also continues to be some interest in intrastromal rings, although this technology is not yet FDA-approved.

While refractive surgeons can use off-label techniques at their discretion for individual patients, many surgeons are unwilling to do so, and many patients consider such techniques to be risky. For example, until the software for multizone/ multipass techniques becomes available, surgeons can perform these procedures by manually stopping and restarting the laser. But doing so is like operating a stick shift rather than a smooth automatic transmission. For a refractive procedure to gain popularity, the key is simplicity. It must be something every surgeon can do, and operating room techniques are becoming less appealing.

IMPACT OF PRK-A
IN THE GRAND SCHEME

Granted, introducing modifications to excimer laser technology in the United States is cumbersome and much slower than what exists worldwide. But the true significance of the FDA's approval of PRK-A is the assurance that we are closer to our goal of being able to offer comprehensive vision correction.

We can anticipate improvements in existing techniques and technology, as well as the introduction of new technology. With each addition to our armamentarium, we will continue to debate the relative merits of different techniques for vision correction. But it's not important which method doctors say is better. What's important is that we're setting the stage for increased acceptance of refractive surgery consistent with our ability to achieve emmetropia for our patients.

Regardless of the relative benefit of PRK-A, we still have one more option than we had before. And, it didn't require a papal edict to get it. This restores our faith that vision correction options are on the drawing board, and in time, they will become available to us.

Refractive surgery and comprehensive vision correction do not depend on the introduction of specific technology, but rather on knowledgeable, experienced and dedicated ophthalmologists and optometrists who are commited to meeting their patients' needs. CLS

Dr. Aquavella is chairman of the Genesee Valley Eye Institute and director of the corneal research lab at the University of Rochester.