HEALTH & MEDICINE :: JUNE/JULY 2008
What You NEED to Know Before Considering LASIK
New Advances in Laser Vision Correction Improve Safety and Reliability
Excimer laser PRK (Photo Refractive Keratectomy) was first performed in the United States in 1987, and was subsequently approved by the FDA in 1995, all but eliminating the use of incisional radial keratotomy to correct nearsightedness. The laser is used to reshape the cornea (the clear front surface of the eye), adjusting the natural focus of the eye and reducing or eliminating the need for distance glasses. Over the next few years, further refinements in technique allowed correction of farsightedness and astigmatism, as well as higher levels of nearsightedness. Lasik (Laser Assisted In-Situ Keratomileusis) was later developed (FDA approved in 1999) to shorten the recovery time, reduce discomfort, and reduce the risk of scarring occasionally seen in PRK (especially in cases of higher prescriptions). In this procedure, a special device is used to create a partial thickness flap of tissue in the cornea (the clear front surface of the eye) under which the laser treatment is directed. The flap is then replaced, and heals without sutures, providing a smooth, untouched front surface which is clearer, less painful, and less prone to scarring. This allows patients to rapidly return to their normal activities with good vision, and also expands the allowable range of vision correction to minus 14 diopters (PRK was previously limited to a moderate minus 6 diopters because of the incidence of scarring (haze).
Though LASIK remains the most commonly performed method of laser vision correction, with over one million procedures performed each year and a success rate of approximately 95%, many patients remain hesitant to trust their eyesight to this surgery. The majority of complications, though rare, relate to the flap created by the LASIK procedure. Complications can include wrinkles (particularly if the eye is rubbed), flap related dry eye, skin cells or debris trapped beneath the flap, and flap dislocation, all of which can adversely affect visual outcomes. In addition, some patients were excluded from LASIK due to thin corneas, which would not accommodate the laser treatment in addition to the flap creation (a certain minimum amount of cornea is required for stability).
LASEK (Laser Assisted Sub-Epithelial Keratomileusis) was introduced in Italy in 1999 as a way of performing PRK with less pain, less scarring and faster recovery of vision, but without the risk or complexity of the LASIK flap. Dilute alcohol is used to loosen the corneal surface cells, which are then slid to the side. The laser treatment is applied, and the cells are replaced to create a “natural” bandage. Unfortunately, though more convenient than PRK, LASEK does not approach the comfort and speed of recovery typical of LASIK.
Epi-LASIK (Epithelial-LASIK) may be the answer that millions of risk-averse nearsighted individuals have been waiting for. This relatively new procedure bridges the gap between LASIK and LASEK, combining their greatest benefits and eliminating their worst disadvantages. Using a device similar to that used to create a LASIK flap, but without a sharp blade, the surgeon precisely separates the surface cells from the underlying cornea and slides them aside. The laser is applied to the underlying bed, and the surface cells are either replaced or discarded, depending upon individual circumstances. The precise separation allows more rapid healing with less scarring (haze) and pain, approaching the convenience of LASIK but without any of the flap related concerns. Also, with some of the recent advancements in custom laser treatments, epi-LASIK surface treatment may afford a greater level of precision and more accurate, clear results.
Wavefront technology, long used to adjust telescope optics, has recently been adapted to measure and correct optical aberrations in the eye. In the last few years, each of the major excimer laser manufacturers has developed a wavefront analyzer to measure unique optical characteristics which, along with the spectacle prescription, can be entered into the laser’s computer to create a completely custom treatment, optimizing visual outcomes. Statistics from national studies show improved results, with fewer complications. There is early evidence that this technology may be even better suited to non-LASIK surface treatments, as the flap itself may alter the previously measured, unique characteristics of the eye which the custom treatment aims to correct.
As a surgeon who puts the safety and long term visual well being of my patient above all other concerns, I have welcomed and embraced these new advances. Since the earliest days after FDA approval of the excimer laser, I have balanced the desire of patients with healthy, spectacle dependent eyes to reduce their need for glasses, with the careful consideration of the potential risks of vision correction surgery. Each individual patient must weigh the risks and benefits of each procedure, and consider their individual circumstances after careful consultation with a surgeon experienced in each alternative. I am excited about the recent innovations which have brought safety to match accuracy and finally make laser vision correction a reality for many patients previously watching anxiously from the sidelines.
Jeffrey B. Minkovitz, M.D., is with Eye Physicians and Surgeons, P.A., 1207 North Scott Street, Wilmington, DE 19806. Dr. Minkovitz is affiliated with Christiana Care, Wilmington, DE; St. Francis Hospital, Wilmington, DE; and Wills Surgery Center, Wills Eye Surgical Network, Wilmington, DE. Dr. Minkovitz served as an Assistant Professor with Johns Hopkins University from 1998-2004. He received his M.D. in 1990, University of Massachusetts Medical School; and his B.A., Magna Cum Laude, Harvard University in 1986. Dr. Minkovitz received his certification in 1996 with the American Board of Ophthalmology and in 1991 received certification with the National Board of Medical Examiners. For six consecutive years, Dr. Minkovitz was awarded the distinction of “Top Doc” for excellence in the field of Ophthalmology in a survey of his peers. Dr. Minkovitz is a highly accomplished surgeon with over 13 years experience. Dr. Minkovitz is fellowship trained in cornea, cataract and refractive surgery. As one of Delaware's leading cataract surgeons, Dr. Minkovitz offers both ReZoom™ and Crystalens® to his patients. For further information or to schedule an appointment please call 302-656-2020 extension 38.
