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What is Wavefront Adaptive Optics?
Wavefront adaptive optics technology is the newest method available to determine the prescription needed to correct vision. All other methods used to determine the prescription required for correcting vision were designed to give the single, average prescription that produced the best vision for the eye. While this worked well for eyeglass prescriptions when only one lens could be made, more options are now available with laser vision correction. Wavefront adaptive optics measures the vision correction required at multiple points and produces a three-dimensional map of the many different prescriptions instead of just the average prescription. Vista is pleased to be the first and only place in the Northeastern United States to offer Vision WaveMap® testing to evaluate patients before vision correction surgery and LADARWave therapeutic measurements for wavefront guided CustomCornea excimer laser vision correction surgery
How can a Vision WaveMap® help me?
Because the Vision WaveMap® shows the eye's many different prescriptions, a great deal more information is gained about how that eye sees. One of the things we have already learned from wavefront measurements is that like our DNA and fingerprints, the prescription for every eye is unique. By computer processing the information about the different prescriptions in the eye, the level of distortion (aberration) can be quantified. Since conventional laser treatments do not correct for distortion at this time, patients with significant preexisting distortion are advised to have CustomCornea surgery where we can use the laser to correct these aberrations as well.
Why was wavefront adaptive optics developed?
Wavefront adaptive optics has been used for years in astronomy. One of the first uses of wavefront adaptive optics in astronomy is revealing in its ability to correct distortion. Over a decade ago NASA launched the Hubbell space telescope. This telescope was to be used for deep space observation without the distorting effects of the earth's atmosphere. Unfortunately, the primary mirror of the telescope was distorted and did not produce sharp images. A wavefront measurement was made on the telescope that measured the distortion in the mirror. With this information a correcting lens of opposite distortion was able to be produced. Once this new lens was in place, the telescope was able to be used for the purpose it was designed, with sharp images being sent to earth. With the development of wavefront adaptive optics measurements, better images were also able to be obtained with land based telescopes. With land based telescopes, the earth's atmosphere will distort the light rays of distant sky objects and decrease the resolution (clarity) of the object. By correcting these distortions with wavefront measurements, astronomers are able to cancel them out and improve the image that is seen through these telescopes as well.
How do wavefront measurements work?
There are a number of different types of methods to get wavefront information about an optical system such as the eye. With "ingoing" aberrometry, a thin laser beam is sent through many different points of the eye and where it falls on the retina is measured. By comparing where the light actually falls with where it would fall if the eye was perfect, the prescription at each point can be determined. With "outgoing" aberrometry, a thin laser beam is sent through the center of the eye. The returning light is passed through an array of lenses to break it up into the parts that will be measured, and collected on a specialized receiver. The position of each point of light on the receiver is then compared to where it would be if the eye was perfect, and again, the prescription for that point is determined.
What is the future for wavefront measurements?
In 2001, wavefront measurements are being used in very few surgeons' offices to diagnose irregularity in the eye as an optical system. Then, Vista was the first to be able to offer this technology to its patients in the northeastern part of the United States. As more wavefront measuring units become available, we at Vista believe it will be a more commonly performed test before laser eye surgery. In October 2002, the FDA approved CustomCornea, the first and only vision correction surgery that uses the patients' unique wavefront information from the LADARWave to design the surgery for the LADARVision excimer laser. With this approval, Dr. Barrie Soloway, Director of Vision Correction at the New York Eye and Ear Infirmary and Medical Advisor to Alcon became the first and only surgeon to offer CustomCornea laser surgery. This surgery can help a patient with excessive distortion in their eye to see better without glasses after surgery by correcting these abnormalities. The use of wavefront measurements to correct eyes with excessive distortiondue to poor results from conventional laser treatments will be the next avenue for investigation at Vista. With CustomCornea, even patients without excessive levels of higher order aberrations can benefit from the advanced algorythms it uses the have been shown to reduce the level of higher order aberrations that conventional surgery and older approved FDA treatments caused. It is this use of wavefront that should help more people enjoy excellent results from laser eye surgery and is the most promising application of this technology.
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