Corneal Surgical Techniques

There is a long history of corneal refractive surgery. Leonardo Da Vinci in 1508 said the theory of refractive errors. The first systematic analysis of the nature and results of refractive errors came from Francis Cornelius Donders. His classic treatise, “On the anomalies of accommodation and refraction of the eye”, outlined the fundamental principles of physiological optics. Ironically, in this treatise, Donders railed against surgical attempts to correct refractive errors by altering the corneal shape. In 1885 Hjalmar Schiotz performed corneal incision to correct astigmatism. Modern refractive surgery extended corneal reshaping to treat myopia and astigmatism. Throughout the 1930s and 1940s, Sato published several reports, describing his attempts to refine incisional refractive surgery with anterior and posterior corneal incisions. The Russian ophthalmologist, Fyodorov later developed a systematic process of anterior radial keratotomy and treated thousands of myopic patients with greater predictability. Lamellar surgery was first introduced by Jose Barraquer. He invented keratoplasty procedures that involved the transplantation of corneal tissue of a size different from the host size to alter the curvature of cornea. He also invented a series of lamellar procedures and developed a formula that represented the relationship between the added corneal thickness and the change in refractive power, later called Barraquer’s law of thickness. The transition from incisional to ablative laser refractive surgery arose with the development of Excimer laser technology. Excimer lasers use argon fluoride gases to emit ultraviolet laser pulses. Taboda and Archibald reported the use of the Excimer laser to reshape the corneal epithelium in 1981. In 1983, Trokel and colleagues showed how the Excimer laser could be used to ablate bovine corneal stroma. In 1985, Seiler did the first Excimer laser treatment in a blind eye. He later did the first Excimer laser astigmatic keratotomy. In 1989, McDonald and colleagues did the first photorefractive keratectomy on a seeing eye with myopia. Jose Barraquer’s pioneering work, including the use of lamellar procedures to subtract corneal stromal tissue and the development of the first microkerotomes, set the stage for laser in situ keratomileusis (LASIK) surgery. Ruiz and Rowsey modified Barraquer’s technique to perform keratomileusis in situ with a geared automated microkeratome. In the early 1990s, Pallikaris and colleagues and Buratto and colleagues independently described a technique that combined two existing technologies: the microkeratome and the Excimer laser. Pallikaris coined the term LASIK for this new technique, which has become a widely used refractive technique worldwide (1).