Those entries that are starred indicate resources that were used in addition to the articles
The article, "Why Settle for 20/20" describes the new technology that is changing the face of LASIK eye surgery. LASIK eye surgery is a procedure that uses lasers to change the shape of the cornea in the eye to eliminate vision problems and the need for a person to wear glasses or contact lenses. This new technology is called Wavefront technology. Prior to Wavefront technology, doctors used age-old standard procedures to diagnose vision proble,s. These include the familiar "eye chart" exam as well as teh test in which a doctor flips a lens in front of the eye to determine which lens produces better vision results. With the outcomes of these eye exams, a doctor is able to diagnose what are known as lower order aberrations whcih include vision problems such as nearsightedness, farsightedness, and astigmatism. However, vision ailments do not end with lower order aberrations. Many patients are inflicted with what are called higher order aberrations and include vision problems like poor night vision, contrast sensitivity, or halo effects around light sources.
While LASIK surgery has always been known for its ability to eliminate lower order aberrations and produce 20/20 vision, Wavefront technology promises it can produce vision superior to that. By using special machiney and software to develop a 3-D image of a patient's cornea, Wavefront technology allows doctors to correct problems unique to one individual patient. In other words, the surgery performed with the Wavefront picture is highly specialized. Wavefront technology is helping to develop customized surgery for those patients who suffer from both lower and higher order aberrations.
Wavefront technology and its relationship to the LASIK surgery and the eye are related to physics in various ways. The cornea functions as a lens that is capable of focusing light to produce images that we are able to see. LASIK surgery uses a laser (light amplification by stimulated emission of radiation) to reshape the cornea and correct light refraction problems in the eye. Finally, wavefront technology uses light waves passed through the eye to construct a 3-D picture of the eye that indicates aberrations.
1 Jan. 2004: 18-19.
In Irvine, CA, a LASIK surgery experiment took place, in which the goal was to discover whether or not a femtosecond laser yielded better results than the commonly used microkeratome laser. In summary, the experiment was performed on nine pairs of eyes to attempt to lessen the amount of ocular aberrations, which is the reason for using the femtosecond laser. Each patient had one eye corrected with the femtosecond laser, while the other was corrected with the Hansatome microkeratome laser by Bausch and Lomb. In LASIK surgery, flaps are created to allow easier access to flawed part of the eye. These flaps are created by the lasers, which then proceeded to correct the eye. After the procedure, patients returned to Dr. Tran, the leading research analyst and ophthalmologist, ten weeks later to compare the results.
Doctors had compare the two lasers years ago and found the final results of "standard refraction and vision outcome measures" to be "excellent and comparable." However, the end result of this experiment proved that in using the femtosecond laser the "flap creation...is associated with less change in ocular aberrations." This was due to the less induced cylinder created by the femtosecond laser. This experiment was a great success for the femtosecond laser. There was less change in lower-order aberrations (defocus and astigmatism), while the microkeratome laser actually increased the number of higer-order aberrations. Also noted, the "visual acuity" was better by using the femtosecond laser, in that "one hundred percent of the eyes saw 20/20 or better." All in all, the femtosecond laser is beneficial to society because it has shown that flap creation minimizes wavefront distortions, which as Dr. Tran states, "could be used for deciding what technology may be preferred for flap creation in wavefront guided custom cornea procedures."
<http://www.fda.gov/cdrh/LASIK/glossary/htm>.
<http://science.howstuffworks.com/eye1.htm>.
<http://science.howstuffworks.com/laser1.htm>.
<http://www.bausch.com/us/vision/concerns/surgery/history.jsp>
LASIK eye surgery is a form of vision correction. Originally, in the 1940s, there were types of vision correction surgery called radial keratotomy, also known as RK and photrefractive keratectomy, also known as PRK. RK aids in the correction of shorsightedness (myopia) and astigmatism (blurred vision), but is only able to treat the most basic levels of such. PRK utilizes a much more precise laser, which is an upgrade of RK. THe only drawback from PRK is that it has multiple side effects and takes slightly longer to recover from. It is also used in the actual LASIK procedure, whereas RK is not.
The main benefit of LASIK surgery is a decreased recovery time with fewer errors. The pain after surgery is less due to the accuracy of the laser which is able to remove a thickness of cornea of 1/1500th of a hair. The newest technology has been able to diminish the damage to the rest of the eye by rather than having one large laser, it is made up of multiple smaller ones.
View. 5th ed. Belmont: Brooks/Cole, 2004.
