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Strategies & Market Trends : Gorilla and King Portfolio Candidates -- Ignore unavailable to you. Want to Upgrade?

To: JRH who wrote (5150)	8/23/1999 3:23:00 PM
From: StockHawk	Read Replies (2) \| Respond to of 54805

Laser Eye Surgery and VISX - Part I: History/Background = Note: I am not an a medical professional. I gathered this information to educate myself about LASIK eye surgery. While I have tried to be accurate, I may have made mistakes or erred in my understanding of the material. Some of the information presented here is just my opinion or the result of inferences that may have resulted form inadequate study. Moreover, the field of laser eye surgery is evolving rather rapidly and new developments can be expected. I present this as a starting point for discussion. = The idea that eyesight could be altered using surgical procedures apparently germinated in the 1800's. This was based on observations that some individuals who experienced cornea injury underwent a change in their vision. It was reported that in a few rare cases nearsighted trauma victims had a dramatic decrease in their nearsightedness. In the early 1950's, a Japanese eye surgeon, Dr. Sato began experimenting with surgical cuts in the corneas of volunteers with nearsightness (myopia). In a few cases improved vision resulted, but almost all patients eventually went blind. Nevertheless, interest in reducing myopia continued. In the 1970's experimentation with Sato's incision technique took place in the Soviet Union. The technique became known as Radial Keratotomy (RK). RK was introduced into the US in the late 1970's. In RK the surgeon utilizes a scalpel to make several small cuts which tend to flatten the cornea and improve vision. A pattern is generally followed, similar to spokes on a wheel. No tissue is removed, no material is added, and no sutures are used. While RK did develop into a reasonably effective treatment for many patients, the treatment apparently weakened the eye somewhat and some individuals experienced complications. Perhaps 2 million Americans had RK but today most practitioners believe laser surgery is a much better technique, with much lower chances of post-surgical problems. RK is generally considered an option now only in cases of mild nearsightedness. Another surgical technique, Lamellar Keratoplasty (LK), is a procedure which reshapes the front surface of the eye in an effort to correct farsightedness (hyperopia). LK is intended for the treatment of farsightedness up to about 3 to 4 diopters. It is a relatively rare procedure - (note: most eye correcting surgery is for myopia, not for farsightedness). Using lasers to correct myopia was given initial serious consideration in the 1980's. Two companies pursuing development of laser surgery at the time were VISX and Summit. The initial idea was to use the excimer laser to make the RK cuts in place of a scalpel. This approach was abandoned and replaced by a technique to reshape the cornea. By 1988, VISX and Summit had both received Investigational Device Exemptions (IDEs) from the FDA. Today, laser techniques include Photorefractive Keratectomy (PRK) and Laser Assisted In-situ Keratomileusis (LASIK). PRK and LASIK can be used to correct myopia (by removing tissue primarily from the midpoint of the cornea), farsightedness (by removing tissue primarily from the endpoints of the cornea), and astigmatism (by removing pie shaped sections of the cornea). Both procedures use an excimer laser to reshape the corneal curvature. With PRK the laser light is used to reshape the front surface of the eye. With LASIK the middle portion of the cornea is treated first. A machine called a microkeratome is used to lift up a flap on the surface of the cornea. The laser is then used to reshape the exposed corneal surface. The flap is then laid back in place and heals naturally. LASIK is the preferred procedure used today. LASIK offers the advantages of quicker healing, less pain, less regression of effect (more stable results), and lower incidence of corneal scarring. To the prospective patient, LASIK offers these benefits: 1. Very short procedure time. 2. Quick recovery 3. Very minimal pain or discomfort. 4. A high success rate 5. Few, reasonable side effects. With regards to #5, I do not wish to minimize the existence of post-operative complications or side effects. These can be very real for some patients. I will be discussing these later. Initially LASIK was used in the US to treat a rather small range of patients - those with mild myopia. Gradually, treatment of more severe cases has evolved. In some ways, it has been possible to foresee the future of LASIK in the United States by looking outside the US. Other countries, notably Columbia and Canada have been pioneers in the procedure. Surgeons in these countries have been able to treat patients with more severe myopia and they have been allowed to utilize a great array of lasers. END PART I In Part II, I will discuss the development of LASIK and the companies that manufacture the laser equipment. StockHawk