Calgary Epi-LASIK, LASIK, PRK, Intra-LASIK: What is Custom Wavefront Laser Vision Correction?

By February 26, 2010 Uncategorized No Comments

Once you decide you are interested in having laser vision correction surgery there are several things to consider. Which procedure is best for you? Which surgeon to choose? How much will it cost? What type of laser will be used?

Laser vision correction can be done by making a corneal flap and placing the laser treatment under the flap; the flap can be made by a mechanical microkeratome for LASIK or with the femtosecond laser with Intra-LASIK. Many surgeons are favoring surface no-flap treatments due to the lower risk and equally good long term results; no flap treatments include PRK and Epi-LASIK.

For either no-flap or flap treatments the application of the laser can be a standard treatment or a customized wavefront treatment. The standard treatment will treat simple sphere (nearsighted or farsighted) corrections as well as astigmatism corrections. For a true custom wavefront treatment measurements are made using a wavefront analyzer before surgery. The wavefront analyzer uses infrared light which is projected into the eye; the light is measured as it exits the eye and analyzed to provide an aberrometry map. The aberrometry map contains information about the simple sphere and astigmatism corrections along with more complex higher order aberrations. Each individual will have a unique set of higher order aberrations. The Wavescan aberrometer uses approximately 240 data points to create a unique aberrometry map that can be used for a truly customized wavefront treatment by the Visx S4 IR excimer laser.

The Visx laser is the most widely used excimer laser in North America. For customized wavefront treatments the wavescan aberrometry map data is loaded into the Visx S4 IR excimer laser for each unique eye to be treated. The wavescan aberrometry map also contains information regarding iris landmarks (the iris is the colored part of the eye surrounding the pupil). This iris information is used during treatment to recognize the unique eye to be treated and to adjust the treatment for cyclorotation and iris centration. Cyclorotation is the rotation of the eye which can occur between sitting upright and laying down. For some people this rotation may be greater than 10 degrees. The pupil may also shift slightly in response to lighting conditions. The iris recognition feature available on the Visx S4 IR excimer laser system allows for the precise application of the laser treatment for optimal results.

While many people have had satisfactory results with standard laser treatments, there is evidence to show that true custom wavefront treatments offer better results. An analogy that is often used is that of an off the rack suit compared to a tailor-made suit. Custom wavefront laser vision correction is tailored to your individual eye.

Choosing to have laser vision correction is a big decision. Considering all the factors involved including laser type and standard versus wavefront corrections will help you make the choice that is best for you.

More information is available in Dr. Anderson Penno’s latest book “Laser Vision Correction: What You Need to Know” which is available here.

To book a complimentary assessment with Dr. Anderson Penno, contact Western Laser Eye Associates today.

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