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Conductive keratoplasty (CK) is a non-laser refractive eye surgery designed to correct mild hyperopia and help people who are middle-aged and older reduce their need for reading glasses after they become presbyopic. Unlike LASIK, PRK and other laser-based procedures, NearVision CK uses low energy radio waves to reshape the cornea and restore near vision. During the CK procedure, your eye surgeon uses a hand-held instrument with a tiny probe (smaller than a human hair) to apply low-level, radio frequency (RF) energy to specific spots that form a circular pattern on the outer part of the cornea. Connective tissue then shrinks where the RF energy was applied, causing the circular band to act like a belt that "tightens" and steepens the cornea. This change in the curvature of the eye's surface affects the way light rays enter the eye to bring near vision back into focus. Unlike LASIK or PRK, no tissue is removed from the eye during a NearVision CK procedure that takes only a few minutes. CK also is being investigated as a way to correct certain types of astigmatism that create an irregular eye surface due to trauma or surgical incisions. In conductive keratoplasty, low heat energy from radio frequency is applied through a probe to reshape your eye's surface. The Journal of Refractive Surgery in February 2010 reported outcomes of CK treatment for 13 eyes with this type of astigmatism, including improved visual acuity and contrast sensitivity — as well as reduced sensitivity to glare. A new form of the procedure, called topography-guided conductive keratoplasty, also is being investigated as a safe way to treat keratoconus — an eye disease that causes thinning and irregularity of the corneal surface. In October 2010, the American Journal of Ophthalmology reported results of a small study that showed 15 of 21 keratoconic eyes treated with topography-guided CK achieved more normal corneal symmetry. With this treatment, corneal transplants also were avoided. Imaging of the corneal surface (topography) was used in this method of CK to help create individualized treatments. If you have clear distance vision and your only problem is poor near vision due to presbyopia, conductive keratoplasty is performed on only one eye. This creates a mild form of monovision, meaning that one eye is corrected for near vision while the other eye is stronger for distance vision. As may happen with monovision with contact lenses or a LASIK eye surgery procedure, your driving vision with this type of vision correction may be less sharp than it is when both eyes see clearly in the distance. So you may find a pair of eyeglasses for night driving useful after CK. While CK can improve near vision, the procedure doesn't cause as much blurring of distance vision as monovision with contact lenses or laser vision correction procedures such as LASIK. Studies indicate that the CK procedure may alter the cornea in such a way that a slight multifocal effect is achieved, creating "zones" through which the eye may be able to see at different distances. Prior to a conductive keratoplasty procedure, your eye doctor may recommend that you first wear a contact lens for near vision correction on one eye for a period of time to make sure you are able to adapt to monovision. But this is not a requirement. People who adapt well to a monovision contact lens fitting typically are able to tolerate a CK procedure. During your CK consultation, your eye doctor may conduct another test that involves holding a +1.00 diopter lens for near vision correction in front of your non-dominant eye. This way, you can experience (with both eyes open) what it is like to have one eye see better at a distance and the other eye see better close up. If you notice a significant blurring of your distance vision during this test with both eyes open, you may not be a good candidate for the procedure. If you still can see clearly across the room under these circumstances, you likely will adapt well to CK as opposed to San Francisco LASIK. All About Vision. “Conductive Keratoplasty (CK) Reduces Need for Reading Glasses.” March 2011.
http://www.allaboutvision.com/visionsurgery/ck_ltk_eye_surgery.htm
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