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In 1983, studies began on animals and the excimer laser was modified to produce smoother treatments or ablations at lower energies. Human eyes were first treated with surface photoablation which is another term for how the laser reshapes the eye. This surface ablation known as Photorefractive Keratectomy, or PRK, was approved by the U.S. Food and Drug Administration in 1995. In PRK, pulses of light remove minute amounts of the cornea, causing it to change shape resulting in improved vision without glasses or contact lens.
LASIK, Laser Assisted in-situ Keratomileusis took refractive surgery to the next level with faster visual recovery. Through LASIK technology, the excision or ablation is made beneath a corneal flap. Patients reported clearer vision in hours as opposed to days.
In the United States alone, more than 2 million procedures have been performed using laser technology to improve or correct vision. More than 20,000 have been performed in Hawai'i.
Since the inception of the excimer laser for treatment of nearsightedness, farsightedness and astigmatism, there have been many additional technological advances. 1) The laser has been modified to better smooth and blend the treated area with the surrounding tissue. 2) The size of the treatment area can be changed (refractions is the shape. This refers to the diameter of treatment and may have relevance to night vision issues) 3) Most lasers now have an "eye tracker" - a devise integrated into the laser system to track and compensate for any eye movement that occurs during eye surgery.
Refractive technology in Hawai'i
In Hawai'i three different lasers are available - the Nidek EC-5000, the VISX Star S3 and the Autonomous LADAR Vision. What differentiates them is in the way they deliver the laser energy to the cornea, or surface of the eye.
The Nidek laser is a scanning slit laser, which basically means its beam of light is slit-shaped.
The Star S3 is a broad beam laser. The beam is modified by diaphragms and lenses based on each patient's prescription. LADAR is a small beam laser and the treatment is delivered using a 0.8 millimeter spot size. Each laser can vary the size of the treatment zone and what is called the blend zone. The blend zone lies between the treated area and untreated tissue, and is smoothed to avoid a lip or edge.
Some research indicates the size of the treatment zone and the blend zone are important with respect to night vision, specifically glare and halos seen in dim lighting situations.
The flap
Whatever the laser type, in LASIK procedures, a thin corneal flap is lifted and the laser reshapes the cornea beneath the flap. The flap, which remains connected by a tissue hinge, is replaced over the treated are, protecting it and promoting a rapid recovery. The keratome, the devise used to make the flap, has been in use since 1949. Over the years, modifications have been made to increase the safety and predictability of making the flaps. There are several types of keratomes used in Hawai'i, but there is little difference among them in terms of outcome. The type of technology used for this part of the refractive surgery is not as important as how comfortable the surgeon is with it, and the surgeon's level of experience.
An interesting new technology called the femtosecond laser is now being evaluated which uses a laser beam to make the flap. This may prove even more reliable and predictable than keratomes. This technology will probably not be available for a few years.
The wave in LASIK technology
Probably the biggest sensation in refractive surgery this year is wavefront analysis of vision. Up to now, the level of treatment needed has been determined by a fairly accurate, subjective determination of prescription; the patient tells the doctor which corrective lens makes eye chart letters clearer. Wavefront analysis is a more detailed measure of the entire optical system. Using the wavefront technology, we can get a better idea of the distortions a ray of light undergoes as it travels through the eye. By identifying all these distortions - in addition to nearsightedness, farsightedness and astigmatism - we may be able to adjust the laser to get even better outcomes.
The VISX WaveScan® Wavefront system is the only one FDA-approved for measuring refractive errors in higher order aberrations. For example, a normal prescription for eyeglasses corrects to a up to the third level of aberrations or blurriness. This new, sophisticated technology allows us to determine higher levels of aberration in the light refracted by the eye. The devise also allows the patient to experience what his or her vision would be like with all the levels of blurriness or aberration corrected.
By coupling the wave system with the tracking capabilities of the new Visx Star S4 upgrade, custom laser treatments have become a reality. Both LADAR and Nidek laser manufacturers are connecting wavefront analyzing systems to their lasers to perform wavefront-guided procedure. This is an exciting development although its impact on laser refractive surgery has yet to be determined.
Technology vs. experience
Technology is clearly important, but as with any surgical procedure, the choice of surgeon is critical to the outcome. Experience matters. Preoperative screening is vital to a successful procedure. A preoperative evaluation should include not only a thorough eye exam; but measurement of the pupil, mapping of the cornea or front surface of the eye and evaluation for dry eyes as well. There should be a lengthy discussion with each patient about his or her visual needs at work and at play to determine whether laser refractive surgery is appropriate. Although rare, complications can occur. An experienced surgeon can manage complications in partnership with patients for good results.
Laser refractive surgery is a popular, safe alternative to glasses and contact lenses for the treatment of nearsightedness, farsightedness and astigmatism. The procedure is here to stay, and with technological advances outcomes will continue to improve. But it is still a surgical procedure, and sight is a precious commodity. It is important to consult with a surgeon that has experience and expertise. Their knowledge of the technological advances in vision correction is a good indication of both these qualities.
Omphroy, Jenkins Only Hawai'i Surgeons to Receive National Award
Dr. Omphroy and Dr. Jenkins are nationally recognized for their work in laser refractive surgery. Dr. Omphroy and Dr. Jenkins were named VISX star surgeons for 1999. Ranking as a VISX star surgeon places the doctors in the top five percent of refractive surgeons in the nation.
This is the second time for Dr. Jenkins, who was the first Hawai'i ophthalmologist to be recognized by VISX. The VISX laser system was the first device for corneal refractive surgery approved by the FDA to correct three vision problems-nearsightedness, farsightedness, and astigmatism.
The Small Business Administration has selected Dr. Jenkins as Honolulu's Women in Business Advocate for 2004.
"It has always been part of my personal mission to support other women in business," said Dr. Jenkins. "I appreciate SBA's recognition of that." She received the award at the 2004 Small Business Person of the Year Awards Luncheon honoring small business owners from across the state on April 28, 2004. Visit the Honolulu SBA at www.sbahawaii.org for more information.
Dr. Omphroy and Dr. Jenkins are the most experienced laser refractive surgeons in the state, performing both surgical techniques of PRK and LASIK to correct vision. Together they have performed more than 20,000 procedures. Drs. Omphroy and Jenkins are pioneers in laser vision correction and continue to help thousands of islanders begin new lives without the burden of glasses or contact lenses. Because of their experience in laser refractive surgery, both Drs. Omphroy and Jenkins are certified to train other surgeons in the use of the VISX laser, another distinction in Hawai'i held only by the two surgeons.
Breakthrough in Cataract Treatment: ARRAY® Lens
Dr. Omphroy was the first eye surgeon in Hawaii to implant the ARRAY® Lens. An exciting surgical procedure, the ARRAY® lens, brings freedom to cataract sufferers. Cataracts are one of the leading causes of poor vision in the world, particularly in patients over 60.
A cataract occurs when the natural lens in the eye becomes cloudy. Treatment involves surgically removing the clouded lens and replacing it with an artificial intraocular lens.
In the past these implanted lenses were single vision or "monofocal". If the lens were implanted to correct distance vision, eyeglasses would still be required for near vision.
The Allegran ARRAY® Multifocal Intraocular lens corrects vision for both near and far distances. What is extraordinary about this procedure is that the ARRAY® lens works like a set of complex bifocals, reducing the need for eyeglass dependence. The tiny silicone lens has five built-in rings that provide differing levels of long-range and short-range focus. The soft silicone lens is foldable, allowing incisions during surgery to be significantly smaller, which means more rapid recovery.
In US clinical trials in 1997, the year that the Federal Drug Administration approved the ARRAY® lens, 41 percent of patients with the ARRAY® lenses never needed glasses for any reason compared to 11 percent with monofocal lenses. This independence of glasses extends to both near-task use and distance vision.
The ARRAY® lens became available in the US market in March 1998 and Dr. Omphroy became the first ophthalmologist in Hawai'i to implant one. While the lenses are exciting, they may not be for everyone, Dr. Jenkins says. Some patients with the ARRAY® lens report seeing halos around lights at night and complain of glare.
KE ALA 'IKE Success Story Laurie Einstein has been extremely nearsighted since childhood. Her brother, Michael, suggested a LASIK consultation with Dr. Omphroy.
Unfortunately, Dr. Omphroy found that her refractive error, or the degree of her myopia, was too high for LASIK. Usually, -12.00 to -14.00 diopters of myopia is our treatment limit; Laurie was a -18.00!
But Dr. Omphroy discovered something else. Laurie had early cataracts on both sides. Laurie felt completely disabled without her eyewear.
After careful discussions about the risks and benefits, Laurie went ahead with "No Stitch" cataract surgery on both eyes, two weeks apart. Now, she can see 20/20 without glasses most of the time (she wears reading glasses for fine print).
Cataract surgery, or even clear lens extractions, can be done to correct refractive errors. For some, cataract surgery can also be combined with LASIK to obtain even better vision, and more accurate final results. Ask us about your case.
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