by Karen Schroeder, MS, RD
Tired of holding the menu at arm's length to read the choices? In 2002, the FDA approved a new procedure for the correction of farsightednessconductive keratoplasty (CK). Being farsighted makes it difficult to read things at a close distance, such as a computer screen, magazine, or restaurant menu. Many people use reading glasses to correct this common eye deformity, which is also called hyperopia .
The usual cause of hyperopia is a cornea that is too flat. The cornea is a transparent coat at the front of the eye through which the iris can be seen. CK is a method of reshaping the cornea to increase the curvature and make it more "plump." This procedure involves a small probe about the length of a pen and as thin as a human hair. The probe is applied in a circular motion along the outer cornea to heat and shrink small areas of corneal tissue, which then form a constrictive band. This process increases the overall curvature of the cornea.
What differentiates CK from the already available procedures LASIK and noncontact laser thermal keratoplasty (LTK)is that CK uses radiofrequency energy rather than a laser. Radiofrequency energy has been used since the 1950s in other types of surgery. This method is slightly less invasive than laser therapy, which actually removes a small portion of the corneal tissue.
Seeing Results A study published in the April 2002 issue of Ophthalmology , the clinical journal of the American Academy of Ophthalmology, found CK to be as effective as LASIK and possibly more effective than noncontact LTK. This study examined the first 54 eyes treated with CK. One year after the surgery, 93% of the treated eyes had 20/40 vision or better, including 57% with 20/20 vision or better. A larger study completed in 2005 reported similar results in 400 eyes operated on by 19 surgeons. There was, however, about a 20% decline in surgical effectiveness at 24 months. Whether this loss would be likely to continue with time is still unknown. Four of the eyes operated on had a loss of visual acuity of two lines on the eye chart. This was judged to be a sufficiently safe outcome, but does serve as a reminder that some people had vision that was worsened by the procedure. CK takes only minutes to complete and can be done in your doctor's office. You'll be given topical anesthesia in the form of eye drops. If necessary, both eyes can be done at the same visit. You do not need to wear a patch over your eye after the procedure, and most people can return to work and their normal activities the next day.
Vision typically begins to improve about one week after CK and can take several weeks to reach the final level of correction. With all vision corrective procedures, however, there are fluctuations in vision in the first year. With CK, the benefits seen may not be permanent. It should be noted, however, that CK is still relatively new. More studies are needed to determine the long-term safety and effectiveness of this procedure. In addition to glasses and contact lenses, other procedures are available to correct hyperopia, including hyperopic Lasik and the use of implantable lenses. RESOURCES: Food and Drug Administration http://www.fda.gov American Academy of Ophthalmology http://www.aao.org/ References Duffey RJ, Leaming D. US trends in refractive surgery: 2003 ISRS/AAO survey. J Refract Surg. Jan-Feb 2005;21(1):87-91. McDonald MB. Conductive keratoplasty: a radiofrequency-based technique for the correction of hyperopia. Trans Am Ophthalmol Soc. 2005;103:512-536. Last reviewed December 2006 by Lawrence Frisch, MD, MPH Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
