Many people are unaware that LASIK is actually a two step procedure - step one the creation of the flap and step two the actual laser treatment to correct your vision.
2 In step one, we create a micro-thin flap of tissue on the outer layer of your eye, also known as the cornea. The flap is important for rapid healing, greater comfort and better vision. If it is too thick, too thin, or irregular, it could affect the quality of your vision.
Until recently, this step could only be accomplished with a mechanical device called a microkeratome. Now an amazing new FDA approved laser technology called Intralase® has become available that makes the first step of flap creation even safer and more precise than ever before. IntraLase® uses femtosecond technology, which was originally developed by Harvard physicists in the early 70s and later earned the Nobel Prize for Chemistry in 1999. A femtosecond is one quadrillionth of a second. To give you an idea of how short a femtosecond is, there are the same number of femtoseconds in one second as there are minutes in the age of the universe, some 12 billion years. The use of the femtosecond laser in the field of ophthalmology was developed by a team of physicists, biomedical engineers and ophthalmologists at the Center for Ultrafast Optical Sciences and the Kellogg Eye Center of the University of Michigan.
Creating The Laser Flap
The IntraLase® ultrafast femtosecond laser is the first bladeless laser technology for performing Step One of LASIK and the most accurate technology for corneal flap creation available today. The laser uses an infrared beam of light to precisely separate tissue through a process called photodisruption. In this process, the focused laser pulses divide material at the molecular level without the transfer of heat or impact to the surrounding tissue.
- IntraLase® creates the flap from below the surface of the cornea, using an "inside-out" process.
- The silent beam of laser light is focused to a precise point within the stroma (central layer of the cornea) where each pulse of the laser creates a tiny 2- to 3-micron bubble of carbon dioxide and water vapor.
- Thousands of these microscopic bubbles are precisely positioned to define the flap's dimensions, as well as the location of the hinge.
- Bubbles are then stacked along the edge of the flap up to the corneal surface to complete the flap.
- The process from start to finish takes approximately 22 seconds.
2 In Step Two, your doctor folds open the flap so that an excimer laser can be used on the inner cornea to correct your vision. Your flap is then returned to its original position where it seals without stitches.
There are some situations in which IntraLase® is clearly beneficial to patients looking into LASIK. In those who have been diagnosed with dry eye, IntraLase® spares more of the sensory nerves in the cornea responsible for reflex tearing than the manual keratome. IntraLase also places less pressure on your eye than the microkeratome. Aside from comfort considerations, this creates greater safety for patients who are glaucoma suspects. IntraLase® can also allow some of those who were not previously considered candidates due to thinner corneas, the ability to have the procedure. This is because IntraLase® is more accurate, and hence flaps can be made thinner. Finally, although LASIK has been performed safely for years, many potential candidates have been resistant due to fear of the mechanical creation of this corneal flap. If fear has been a major obstacle to your pursuit of laser vision correction, IntraLase® should provide you the peace of mind needed to move forward with the procedure.