CK and Surgery for Presbyopia

Conductive Keratoplasty (CK)

CK is used for treating presbyopia. Presbyopia is the inability of the eye to focus at all distances, usually noticed when fine print starts to blur.

Persons under the age of 40 have no problem for focusing for reading or for working with computers. Persons over 40 years who need reading glasses notice blurring of the distant vision when looking through the readers. Using a monocle on one eye (as seen in old movies) solved this blurred distant vision problem by virtue of giving the wearer monovision. Next to come was the use of bifocals, trifocals and “progressive lenses” to avoid the inconvenience of monovision. Presbyopia typically begins between the ages of 40 and 50. Some doctors disagree about what causes presbyopia. The cause is due to several factors like the increase in the bulk of the lens, the weakening of the ciliary muscles and the increase of the rigidity of the sclera (“white” of the eye)) or a combination of some or all these. Close up vision is a problem in this age group even if you have perfect distant vision normally or after LASIK or PRK.

One of the first effective surgical options for patients having LASIK or PRK was to do monovision correction if they were of presbyopic age.. Surgical procedure such as LTK (Laser Thermo Keratoplasty) using Holmium Laser on the non-dominant eye for presbyopic persons who had perfect normal distant vision gave good results by producing monovision in some patients.
Conductive Keratoplasty or CK is another monovision technique similar to LTK. One eye is treated (preferably the non-dominant eye) so it can see better for near, while the other eye (which is not treated) is good for distant vision. It is a good idea to try monovision with contact lenses as a trial before going ahead with CK, to make sure you'll adapt to it. : After using numbing eye drops to eliminate any possibility of pain, the eye doctor imprints the cornea with a circular treatment pattern. Then, using a tiny probe, the surgeon applies radio waves in the circular pattern to heat the cornea Although it is described as “non invasive” or “Minimally Invasive” the depth of heating the cornea is 80% or more of the corneal thickness to be effective. Reading glasses may be still necessary after CK, as the person gets older. Unlike monovision correction by contacts, LASIK or PRK correction by LTK or CK is not reversible. Perhaps that is why CK is not used by many refractive surgeons
Eyetech has stopped doing monovision correction by LASIK or PRK unless the patient wishes such a correction. It is our experience that most monovision patients come back to have distant vision restored. Eyetech has stopped using LTK, which produced similar results like CK because of irreversibility, regression and dislike of monovision by lot of patients.

Other surgical procedures for Presbyopia

Accommodative Lens Implants

This involves removing the clear lens from the eye and using a flexible lens implant like “ReStore” or “Cristalens” or similar lenses. The procedure is invasive and expensive. This is not available here...

Surgical Reversal of Presbyopia (SRP) with Scleral Expansion Bands (SEBs)

Here, the surgeon makes incisions in the sclera and inserts plastic or metal segments just below the surface of the sclera, weakening the sclera between the muscles that focus the lens and the lens itself... Overall, some eyes that have received the implants show improvement, and some do not.

Anterior Ciliary Expansion

Only here the actual cause presbyopia is addressed. Unlike LTK or CK it will not affect the distant vision. The cornea is not involved in this procedure. It is not invasive like implanting accommodating lenses. The procedure involves weakening the sclera by using Erbium-Yag laser on the sclera (the “white of the eye”).Dr.Kadambi at Eyetech has used this procedure with good results. The greatest advantage of this is that the cornea, clearest part of the eye, is not at all touched or altered. This shows great potential.