CK Proves Its Worth in the Surgical Toolkit

Many patients can benefit from this improved procedure.

BY Y. RALPH CHU, M.D.

Skepticism is probably the word to describe how the vast majority of ophthalmologists today view the surgical correction of presbyopia. After all, there is no one treatment now available that can satisfy the needs of most patients with presbyopia.

We are well aware of the outstanding refractive results we achieve in cataract and laser refractive surgery today. I think it is time to step back and take a different view regarding the surgical correction of presbyopia, particularly the role that NearVision CK (Conductive Keratoplasty, Refractec, Irvine, Calif.) can play. It is time to start viewing the treatment of presbyopia as a dynamic process in which patients may need fine tuning over time as the eye continues to age and vision changes.

A Value-added Treatment

We have performed CK for more than 3 years now and have come to realize that it is truly the most effective, entry-level treatment we have for presbyopia at this time.

When CK was initially introduced, I was among the skeptics, particularly because it was initially a treatment for hyperopia only. The failure of holmium laser thermokeratoplasty left a bad impression with many ophthalmologists. But, as the indications for CK increased with the NearVision presbyopia approval, I became more open to it as a treatment option. And, with the advent of the LightTouch technique, which allows you to use less pressure to apply the CK spots, we are quite pleased with the technology and its results.

This is particularly true for plano presbyopes who suddenly find themselves needing reading glasses for the first time in their lives. It is also true for post-LASIK patients, who have reached their early to mid 40s, and find that after 10 to 15 years of excellent vision they now need reading glasses. A third group of patients who can benefit from CK have received a multifocal IOL and have some residual astigmatism or need some adjustment in their near vision.

These three groups are particularly receptive to the concept of NearVision CK because of its relative simplicity. Plus, you can retreat their eyes if necessary, although in the time that we have been performing this procedure there has been minimal regression of effect. We tell patients that the effects of NearVision CK will last 2 to 3 years and have found they are quite accepting of this concept.

Explaining the Treatment Options

If a patient in his or her early-to mid 40s is looking for a solution to presbyopia other than reading glasses, we introduce the concept of NearVision CK. With patients in their 50s, we first check to see if there is any change in their lenses before discussing treatment options, which would include multifocal IOLs.

With post-LASIK patients, convincing them to undergo NearVision CK is relatively straightforward. They have done the research before and made the commitment to undergo a surgical procedure, so they are open to additional treatments and advancements in technology that can help improve their sight.

In order for prospective NearVision CK patients to gain an understanding of what their vision will be like, we have them undergo a contact lens trial for about 1 week using a monofocal contact lens on their non-dominant eye. Although some advocate the use of a multifocal contact lens, we have been very happy with our results. We have also found that if patients tolerate the contact lens trial, they will be happy with the vision in their CK-treated eye. In fact, we have a 100% conversion rate for patients who tolerate the monovision contact lens trial.

Impressive Results

I have been one of the surgeons taking part in Refractec’s clinical study for expanded FDA labeling to include treatment of post-LASIK eyes. This multi-center study involved 150 eyes of 150 patients who had undergone LASIK at least 1 year previously. The intended correction was a 1.25 D add. Eight CK spots were used with a treatment zone of 8 mm.

At 3 months, no patients lost 2 or more lines of vision or had a best spectacle corrected visual acuity (BSCVA) of worse than 20/40. These results were well within the FDA limits for safety. In terms of effectiveness results, 96% of patients had an uncorrected near vision of J3 or better at 3 months, with 75% reading at J1 or better. Ninety-four percent of patients achieved a manifest refractive spherical equivalent within 1 D of the targeted correction.

The subjective patient results are also quite interesting. At 3 months postop, 95% of patients said they could now read a computer screen without glasses, compared to 69% preoperatively. Prior to NearVision CK, only 28% of patients said they could read a menu or golf scorecard without their glasses. After treatment, 92% said they could now do this task without readers.

I’ve also looked at the results of a series of pseudophakic patients to improve their functional near vision. In this series, 19 eyes of 19 patients were treated with NearVision CK in their non-dominant eye, using one of the following three treatment patterns:

• 8 spots @ 8 mm
• 8 spots @ 7.5 mm
• 8 spots @ 7 mm

These eyes had a variety of IOLs implanted in their CK-treated eye:

• Tecnis ZA900 in 15 eyes
• Alcon SN60WF in 2 eyes
• eyeonics crystalens in 1 eye, and;
• Array SA40N in 1 eye

The median age of the patients in this study was 63.5 years with a range of 47 to 76 years. The main criterion for treatment was a peripheral pachymetry of greater than 560 μm. At 3 months postop, no eyes had lost greater than 2 lines of BSCVA and no eyes had greater than 2 D of cylinder. Eighty percent of eyes had an uncorrected near vision of J3 or better. Overall, most of the patients were quite happy with their enhanced near vision, although three did require additional treatment to further enhance their near vision.

Consider the CK Option

We believe the results for both the post-LASIK NearVision study, as well as the results in what I like to call the "Presbyoptics" study, show that NearVision CK is a good choice for improving near vision in these patients.

I also think the results will only get better with the introduction of a new OptiPoint corneal template that CK surgeons are starting to use to apply the treatment spots. One of the barriers to good results in the past was that CK was a freehand technique and surgeons had to go through a learning curve. With the new OptiPoint template, you center the template on the cornea and let it guide your placement of the spots. I have begun to use this and am more than satisfied with the results so far.

In the time since adding NearVision CK to the services we offer at our practice, it has become a critical tool, particularly as the number of presbyopes continues to grow. We have also noticed an upsurge in interest as a result of the increased promotion and availability of multifocal IOLs. In some patients, these IOLs are not going to work, so you must be ready and able to offer alternative options and customize treatments to the needs of the patient.

If you have looked past NearVision CK over the years waiting for that perfect presbyopic treatment, now is the time to rethink your options. There is no perfect solution for all presbyopic patients and NearVision CK is the easiest, most effective and safe way to start evolving your practice to better assist this growing population. OM

Y. Ralph Chu, M.D., founder and medical director of Chu Vision Institute, Edina, Minn., is a recognized leader in refractive and cataract surgery. He is a fellowship-trained corneal specialist whose practice focuses on refractive, cataract and corneal surgery. Dr. Chu is a consultant to Refractec.