keratoplasty image Tired of holding the menu at arm's length to read the choices? In 2002, the FDA approved a procedure for the correction of farsightedness—conductive 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 distance or reading glasses to correct this common eye deformity, which is also called hyperopia . People with hyperopia tend to need reading glasses at an earlier age than those with myopia (near-sightedness) or no need for distance correction

CK will not cure presbyopia, which is age-associated eye changes that prevent older people from seeing near objects through the same glasses they use for viewing distant objects. However, a technique called monovision may be done. In this case, one eye is corrected for distance vision and the other is left nearsighted to allow focusing on near objects without glasses.

Correcting the Cornea

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 journal 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.

More studies are needed to determine the long-term safety and effectiveness of CK. In addition to glasses and contact lenses, other procedures are available to correct hyperopia, including hyperopic LASIK and the use of implantable lenses.