Dr Anupam Chatterjee, Contact Lenses

Author: Ryan Arsendatama

LASIK (Laser-Assisted In Situ Keratomileusis) is a refractive laser eye surgery procedure that corrects vision problems. This procedure is preferred to PRK (Photorefractive Keratectomy), as it takes less time for the procedure, as well as for recovery. As far back as 1898, the basic principles of radial kerototomy had been laid down by Lans, a Dutch professor of Ophthalmology. During 1930s, Sato in Japan did some pioneering work with corneal incisions. However, it was only in the 1970s that Dr. Fyodorov brought about practical application of refractive surgery through radial keratotomy in the then Soviet Union.

In 1978, American ophthalmologists became interested in the findings of Dr. Fyodorov. After visiting him in the Soviet Union, Dr. Leo Bores brought the technology back to the United States. Since then, radial keratotomy has been performed on over two million Americans. Research into alternate forms of refractive surgery was prompted by certain limitations of radial keratotomy.

Laser Assisted Refractive Surgery

During the early 1980s, Dr. Srinivasin of the IBM research laboratories first used Excimer laser on biological tissue. This was followed up by Dr. Steven Trokel, an ophthalmologist working with Dr, Srinivasin, who introduced the idea of using laser to reshape the cornea.

The excimer laser has a record of accomplishment of safety internationally, since its introduction in 1987. In 1988, the first photorefractive keratectomy was done in Germany. Since then, more than two million people have had their vision corrected through PRK procedure in over 40 countries. Laser refractive surgery has been found to be the most effective with Myopia, Hyperopia and Astigmatism. The success of laser refractive surgery has encouraged the development of newer laser refractive surgery procedures.

LASIK Eye Surgery is the latest in refractive eye surgeries. In comparison to PRK, in LASIK the cornea remains largely intact and the patients’ vision become better more quickly. Reshaping of the cornea has been going on for 50 years, and the Excimer laser has been in use since the 1980s. The first clinical trial using the LASIK procedure was performed in 1991. LASIK uses a device known as Microkerotome - a precision surgical devise with an oscillating blade for creating a corneal flap.

Author: R Heavner

LASIK (laser assisted in-situ keratomileusis ) is probably the most commonly performed laser eye surgery procedure and tends to be what people think of when considering laser surgery for vision correction. However not all patients may be ideal candidates for LASIK surgery due to variations in cornea thickness and curvature. Photo refractive keratectomy ,or PRK, may be the better option for vision correction in some patients who are not able to have LASIK.

Prior to the introduction and subsequent popularity of LASIK, PRK was the most common refractive eye surgery procedure performed. Both LASIK and PRK share similarities in that an excimer laser is utilized to sculpt and reshape the cornea of the eye in accordance with the patients medical needs. Both techniques are used in the correction of myopia (nearsightedness), hyperopia (farsightedness), astigmatism (blurred vision resulting from corneal irregularity), or a combination thereof. Likewise, both are outpatient surgical procedures which may be performed in a physicians office or clinic setting. There are however a few differences in the two procedures.

In a LASIK procedure a small flap is cut with a special tool on the exterior of the cornea. The computer controlled excimer laser is then used to reshape the corneal tissue under the flap. The flap is then replaced over the cornea where it will adhere to the eye and serve to protect it. In PRK, the excimer laser is used to remove tissue and reshape the cornea directly on the surface, or epithelial layer, of the eye. A protective soft contact lens is usually placed over the eye for 3-5 days to allow the epithelial surface to heal.

Several major differences for the patient exist in the two procedures. The first is the recovery period, which tends to be considerable shorter for LASIK patients as opposed to PRK. Likewise, vision improvement with PRK tends to be more of a gradual process than take from a few days to a few months. LASIK patients will in most circumstances experience the benefits of their surgery in a much shorter frame.