Conductive Keratoplasty (CK)
About Conductive Keratoplasty (CK) Surgery
Kellogg patients with hyperopia—or farsightedness—have a new option for vision correction. It is a procedure called Conductive KeratoplastySM, or CK, and it has recently been approved by the FDA.
What is CK?
CK is a procedure that corrects for hyperopia by using the controlled release of low-level radiofrequency (RF) energy, instead of a laser, to reshape the cornea. It is performed in just a few minutes with only topical anesthetic in the form of eye drops.
What is hyperopia (farsightedness)?
Hyperopia occurs when the cornea is too flat or the eye is too short so that light rays focus behind rather than directly on the retina. A hyperopic person has difficulty seeing near objects. Usually glasses or contact lenses are used to improve focus of both distance and near objects.
How does CK work?
The physician uses a small probe, thinner than a strand of human hair, which releases (RF) energy. The probe is applied in a circular pattern on the outer cornea to shrink small areas of corneal tissue. This circular shrinkage pattern creates a constrictive band–like the tightening of a belt-increasing the overall curvature of the cornea.
What happens during the procedure?
After applying drops to numb the eye, the doctor imprints a treatment pattern on the cornea using rinse-away dye. The doctor will have determined the pattern in advance of the procedure, based on the individual patient's amount of hyperopia and details of their examination. The pattern guides the doctor's treatment; each point represents a place where radiofrequency (RF) energy will be applied. Once the cornea is marked, the doctor uses a small probe to apply the energy in a circular pattern to reshape the cornea.
Is CK painful?
The CK procedure is considered painless. The most common sensation that patients experience is a feeling of pressure on the eye. Patients may also be aware of a support or speculum that helps to hold the eye open. After surgery, there may be some mild discomfort, and many patients experience a foreign-object sensation or "scratchiness" in the eye. This usually subsides within 24 hours of the procedure.
Will my vision improve immediately after surgery?
Patients usually notice an immediate improvement in their vision after the CK procedure. However, it usually takes several weeks for the eyes to adjust to the final level of treatment. Patients who are treated for hyperopia, regardless of the procedure, usually require a longer stabilization period than those treated for myopia.
Who is a good candidate for CK?
You should be age 40 or over and meet the following health criteria:
- No drastic changes in vision or eyeglass prescription within the past year
- No eye conditions such as glaucoma, severe dryness, keratoconus, herpes of the eye, aggressive keloid formation or corneal dystrophy
- No physical conditions such as diabetes, pregnancy or nursing, and vascular or autoimmune diseases
If you are interested in CK, you should be evaluated by an eye surgeon.
What is the difference between CK and LASIK treatments for hyperopia?
A major difference is that CK does not use a laser and does not involve cutting the cornea. The outcomes for the procedures compare favorably. According to the academic journal Ophthalmology (April, 2002), the acuity, predictability and stability of sight after CK are better than or as good as that achieved by LASIK (laser assisted in-situ keratomileusis) and LTK (non-contact laser thermal keratoplasty).
LASIK is a refractive procedure in which a laser is used to create a microscopic flap in the cornea. It then sculpts corneal tissue underneath so that the cornea will form a more effective shape. The flap is closed and heals shut. Kellogg physicians currently perform LASIK for myopia, but not for hyperopia.
Can CK be used to treat presbyopia?
CK is currently in FDA Phase III clinical trials to study the procedure's effectiveness for treating presbyopia, which also affects near vision. Presbyopia occurs when the lens inside the eye loses flexibility, preventing the ability to focus accurately on near objects. It is a normal part of aging and affects people at different ages, but generally by the age of 50.
