CK After Cataract Surgery

GApproved by the FDA in April 2002, conductive keratoplasty (CK; Refractec Inc., Irvine, CA) treats moderate levels of hyperopia (specifically 0.75 to 3.00 D of spherical hyperopia) in individuals over the age of 40. By means of the controlled release of radiofrequency energy, CK reshapes the cornea without the use of a laser or scalpel. Since the procedure's approval, physicians have continued to discover novel off-label applications for the technology. One example is the treatment of residual hyperopia after previous ocular surgeries such as IOL implantation and keratorefractive procedures.

CK AS AN ENHANCEMENT PROCEDURE

Study Motivation
Louis D. Nichamin, MD, used CK in an off-label manner for more than 25 eyes that had undergone cataract surgery and lens implantation in order to treat both hyperopia and hyperopic astigmatism.1 One of the factors considered in Dr. Nichamin's study is that routine cataract and lens implantation surgeries are becoming more refractive in nature because surgeons are capable of achieving more accurate refractive outcomes. As a result, patients and surgeons alike have come to expect nearly emmetropic results. Despite the greatly improved accuracy of refractive outcomes after cataract surgery and IOL implantation, surgeons still sometimes miss the mark, resulting in residual myopia, astigmatism, or hyperopia. Dr. Nichamin said the simplicity and remarkable safety profile of CK prompted him to investigate it as a treatment option for residual hyperopia in this older patient population.

Results
Dr. Nichamin reported he was able to treat patients' hyperopia and hyperopic astigmatism with CK and all subjects achieved a good refractive outcome, even those who required an enhancement. He tracked patients postoperatively for up to 1 year. This study has presented a zero complication rate.

Dr. Nichamin asserts that this study effectively demonstrates that surgeons now have another option for treating hyperopia, including that left by other forms of ocular surgery (specifically cataract procedures). Regarding astigmatic correction, he believes CK may represent a paradigm shift relative to limbal relaxing incisions because it steepens and tightens the flat meridian as opposed to limbal relaxing incisions, which flatten or weaken the steep meridian.

ADVANTAGES OF CK
Procedural simplicity is one key advantage CK has over other modalities for treating hyperopia, says Dr. Nichamin. In addition to avoiding cutting or tissue removal, CK spares the visual axis, he adds.

Contrasting the procedure with LASIK, Dr. Nichamin states that CK has resulted in no instances of dry eye and is unassociated with flap-related issues, both of which are commonplace in older individuals and are of concern after cataract surgery. He also points to CK as a reasonably economical procedure.

The CK unit is small and portable, so surgeons can use it in multiple rooms and facilities. In addition, Dr. Nichamin said pa-tients perceive CK as less invasive and less threatening than other currently available treatment modalities.

Finally, Dr. Nichamin comments that the cost of this technology is significantly less than that of an excimer laser platform, and he believes the profit margins are potentially better for an ophthal-mic practice.

Louis D. Nichamin, MD is Medical Director of Laurel Eye Clinic in Brookville, PA. He is a scientific advisor for Refractec Inc. Dr. Nichamin may be reached at (814) 849-8344; nichamin@laureleye.com.
1. Nichamin LD. Conductive keratoplasty after cataract surgery: enhancement technique. Paper presented at: ASCRS/ASOA Symposium on Cataract, IOL and Refractive Surgery; April 13, 2003; San Francisco, California.