Quality Eye Care uses the VISX Star S4 ActiveTrak, with active eye-tracking and IR(Iris Registration). The ActiveTrak 3-D Eye Tracker is a positioning device that uses infrared cameras to actively follow the tiniest motions of the eye in all three dimensions. This allows the patient to relax during the procedure knowing that the laser system is actively following eye movement to ensure greater precision and accuracy during treatment.

Variable Spot Scanning (VSS) is an exclusive VISX laser technology that allows for a larger treatment area. VSS offers the doctor greater flexibility in developing a more individualized laser vision procedure.

Iris Registration (IR) is the first FDA-approved, fully automated, non-contact method of alignment of the correct CustomVue treatment to the corneal site. Using sophisticated algorithms and multiple reference points on each iris, IR ensures delivery of the treatment to the correct area of the cornea.

For more information contact www.visx.com

The excimer laser is the laser used in LASIK, LASEK, and PRK surgery. This particular laser is very precise, removing as little as 0.25 microns of corneal tissue with a single pulse. 0.25 microns is the same as one quarter of one millionths of a meter.

Human hair etched by excimer laser

Put it another way, this is a fraction of the thickness of a human hair, (pictured here) The average treatment removes only about the thickness of a human hair. The fact that this laser can remove so little tissue without causing significant damage to surrounding tissue, makes it ideal for corneal surgery such as LASIK. The laser energy originates from a gas mixture of argon and fluorine. The laser light itself is ultraviolet, and thus invisible to the naked eye.

The laser is controlled by a computer, into which the surgeon enters the desired prescription correction for a patient's eye. The number the surgeon programs into the computer is the patient's refraction (the measurement of the prescription of the eye), usually modified (by the surgeon, based on the results of his lasik cases) to adjust for patient age, the amount of correction, the environment of the laser room (temperature and humidity), the surgeon's specific technique, and other factors. The focusing of the laser, performed by the surgeon, is extremely important.

The laser beam produced by the laser is very complex. The energy or power of the beam must be very carefully monitored by what is termed "fluence testing". The laser should also be calibrated so that whatever the laser is programmed to correct, will be delivered; this is usually done by treating a plastic plate and reading the result much like one does when measuring the prescription of a pair of glasses. In general, calibration should be performed before every third eye that is treated by the laser (after treatment of both eyes of a single patient, before the next patient).

If you understand the above points, two things become very clear:

(1) Laser maintenance is critical to a good outcome. This is not a machine that you just turn on. The optics or focusing lenses that modify the laser beam must be replaced at regular intervals. The humidity and temperature should be kept as constant as possible, otherwise the results of surgery may not be predictable. Trained technicians are a must for laser maintenance.

(2) The surgeon plays a major role in the surgery and outcome. There has been a great deal of emphasis on the high-tech equipment, but the role of the surgeon cannot be minimized. The laser is just a tool which depends on a skilled surgeon to be used correctly. The actual numbers put into the laser are surgeon and laser-dependent. Depending on who does the surgery and which laser is used, the results can be quite different.

While all the current lasers can theoretically treat all types of prescriptions including astigmatism, not all the lasers are FDA-approved to treat all of these types of prescriptions. Treatments not FDA-approved for a given laser can sometimes be done with that laser, in a roundabout fashion, but such use is called "off-label". To add to the confusion, some lasers that are FDA-approved to treat certain types of prescriptions are only approved to do so using the PRK technique. When these lasers are used to treat these types of prescriptions using the LASIK technique, such treatment is also called "off-label". "Off-label" does not necessarily mean that this is unsafe, only that the FDA has not examined the data to draw any conclusions. The FDA is not in the business of telling doctors how to practice medicine. This is why, for example, some prescription medications are routinely used for reasons other than the original indications.

Ask your doctor whether your prescription can be treated with the laser he or she uses, and whether it will need to be treated off-label.

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