Refractive Eye Surgery History

Refractive surgery is most frequently conducted to correct myopia (nearsightedness), hyperopia (farsightedness) and astigmatism (irregularly shared cornea). Traditionally, several different procedures have been used to surgically correct vision -- most using the same basic concept that changing the shape of the cornea can correct refractive errors and improve vision.

Beginnings of Refractive Surgery in Europe

• Although Leonardo di Vinci discussed the possibility of refractive errors back in the sixteenth century, the first real movement towards correction of visual errors by surgery did not occur until the 1800s. In 1869, the Dutch ophthalmologist who created the modern day eye charts, Herman Snellen, noted that astigmatism could be corrected by making incisions in the cornea. Then, in 1898, L.J. Lans noted that reshaping the cornea with incisions would change the path of light traveling in the eye and refocus it correctly on the retina. This was procedure was called keratotomy.

Radial Keratotomy

• During the 1930s and 1940s, a Japanese ophthalmologist named Tsutomu Sato performed multiple procedures to further explore the concept of keratotomy. His research created the basic procedure of radial keratotomy (RK), which attempted to treat myopia and astigmatism by making multiple spoke-like incisions on the cornea. However, a Russian scientist, Svyatoslav Fyodorov, perfected RK by leaving a clear area in the center of the cornea while making these incisions. Fyodorov also developed a formula to predict the visual outcome of this procedure on a patient.

RK in the USA

• RK was introduced in the United States in 1978. The National Eye Institute started the PERK study (Prospective Evaluation of Radial Keratotomy), which showed that RK was effective in correcting vision. However, it was noted that some eyes had a lack of visual stability over time. Instruments used to perform the procedure were improved and the RK procedure became quite popular in the U.S. during the 1980s. In order to correct astigmatism, surgeons also developed the astigmatic keratotomy procedure, or AK, which could be performed at the same time as RK. With the development of newer technologies, RK had become obsolete by the 1990s.

The Excimer Laser and Photorefractive Keratectomy

• In the late 1970s, the excimer laser was developed -- originally to create computer chips. It was a "cool" laser and thus caused no tissue damage. Ophthalmologists began using this laser's precise mechanism to perform refractive surgery by removing precise amounts of tissue from the epithelium of the cornea. In 1983, Stephen Trokel presented data on photorefractive keratectomy (PRK) and the excimer laser and soon performed the first procedures. In 1985 and 1986, the excimer laser was introduced to the ophthalmic community at large; the FDA then approved the excimer laser for refractive surgery; and PRK became the common refractive surgery procedure performed. However, over time some patients who received PRK developed corneal cloudiness or haze.

Laser Assisted In Situ Keratomileusis

• In Columbia, Jose Barraquer had developed a procedure that involved a layered surgery in which corneal tissue was removed using a small blade. This tissue was frozen, reshaped and placed back on the eye correcting vision. Further research showed that the corneal tissue did not need to be removed. In 1990, laser in-situ keratomileusis, or LASIK, incorporated this knowledge by creating a corneal flap, instead of removing the cap of corneal tissue. Then, after using the excimer laser to dissolve some of the tissue underneath the flap to correct the refractive error, the flap was placed back on the eye. The FDA approved LASIK in 1999 and LASIK is now the most commonly performed refractive surgery in the U.S. LASIK can be used to correct myopia (nearsightedness) and hyperopia (farsightedness).

Further Advances

• The LASIK procedure itself has been refined to expand its treatment range as well with improvements in the process and in the excimer laser. One of these refinements is the custom wavefront procedure which uses three dimensional measurements to correct the cornea. Another update on the procedure uses a laser instead of a blade to create the flap in LASIK. However, everyone is not a candidate for LASIK. Patients with thin corneas, large pupils or certain diseases (connective tissue or vascular diseases) are not typically eligible for the procedure. Newer procedures are being developed, such as implantable contact lenses, which are similar to the intraocular lenses that are used in cataract surgery. In this procedure, the natural lens of the eye is left in place and the additional lens is placed inside the eye.