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Posted on Apr 04, 2005, 6 a.m.
By Bill Freeman
Currently, the number of people having LASIK in the United States exceeds 1 million every year. The LASIK procedure is a two-step process. The surgeon must first gain access to the cornea by creating a flap of tissue. The tissue is folded back, and the surgeon is then able to perform the correction treatment on the inner layer of the cornea.
In the past, the surgeon created the corneal flap with a hand-held mechanical device known as a microkeratome, which utilizes a surgical blade. Although this method has had a high rate of success, surgeons consider it to be unpredictable and perhaps the main source for many of the reported complications.
INTRALASE: LASIK surgery has been revamped. With the IntraLase laser, surgeons use a laser, not a blade, to create the corneal flap. The accuracy of the laser is reported to be 100-times more accurate than the blade. This gives the surgeon more control during the procedure and even allows customization of the corneal flap for each individual patient. Because of its consistent accuracy, IntraLase now makes it possible to treat many patients who were dismissed as candidates for laser vision correction due to thin corneas. The IntraLase procedure uses infrared light to precisely cut tissue by a process known as photodisruption. Special software guides the laser beam into a small, 2 to 3 micron spot of energy. The beam passes harmlessly through the outer layers of the cornea until it reaches its exact focal point within the central part of the cornea (known as the stroma). Upon reaching this focal point, the beam forms a microscopic bubble of carbon dioxide and water vapor. Thousands of these bubbles are placed at a precisely controlled depth to define a dissection plane. By using the rapidly fired IntraLase laser and interconnecting the bubbles very tightly, the surgeon can create a corneal flap with remarkable precision and accuracy.
MORE ON SAFETY: Most surgeons agree the main safety issues in laser vision correction are related to the use of the mechanical device used to create the corneal flap. The IntraLase laser gives a unique level of safety because of its level of precision. Researchers say IntraLase technology is as much as 100-times more accurate in creating the flap than the traditional approach with a surgical blade. The precision was tested and also documented in studies conducted for the Food and Drug Administration clearance of the laser, where the accuracy of flap thickness was demonstrated at /- 10 microns, which is quite precise. Precise flap thickness is important for a successful LASIK surgery outcome. Finally, greater flap stability was also demonstrated with the IntraLase in studies for the laser's FDA submission. The assurance that the flap will be securely re-positioned without incident provides added comfort and tranquility for many eye patients. Surgeons across the United States are quickly adopting the IntraLase laser as the norm. Approximately 100,000 eyes have now been treated with this advanced technology.
