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Fine-Tuning the epi-LASIK Procedure
Surgeons make it a more patient-friendly experience.
BY JERRY HELZNER, SENIOR EDITOR

Thanks to a group of dedicated refractive surgeons who have devoted a great deal of their time to improving epi-LASIK, patients who choose this procedure are finding that they can now expect less pain, faster healing and quick visual recovery.

This article will explore the primary reasons why the work of these surgeons is making epi-LASIK a more patient-friendly experience, enabling it to close the gap with LASIK as a procedure of choice.

A Growth Trend

The epi-LASIK procedure, which was no more than a blip on the refractive surgery radar screen only 2 years ago, does not yet pose a major challenge to LASIK, but it is expected to account for approximately 5% of all U.S. laser vision correction procedures in 2006, up from an estimated 1.5% last year. Even more telling is the fact that a number of the country's refractive surgery thought leaders, including H.L. "Rick" Milne, M.D., Marguerite McDonald, M.D., Eric Donnenfeld, M.D., Barrie Soloway, M.D., Thomas Claringbold, D.O. and Dimitri Azar, M.D., are now choosing to perform epi-LASIK on an increasing percentage of their patients.

The growth in epi-LASIK also coincides with renewed interest in the overall range of surface ablation procedures. Though the industry newsletter MarketScope reports that LASIK currently accounts for approximately 89% of all laser refractive procedures performed in the United States, there is evidence of a slow but steady growth trend back toward surface procedures.

This trend has been confirmed by the results of two recent surgeon surveys, one conducted by MarketScope and the other the annual Duffey/Leaming survey of trends in refractive surgery.

Although LASIK has been an extremely successful procedure, industry analysts agree that the penetration of the potential refractive surgery patient population is still relatively low.

A large number of candidates have chosen to remain on the sidelines, often because of a stated reluctance to undergo blade-created flap creation as part of the procedure. Most industry observers believe that the recent introduction of femtosecond laser technology, which eliminates the blade-created flap from the LASIK procedure, has helped ease the fear factor that had previously existed among many potential patients. Still, advocates of surface ablation say that many of today's refractive surgery candidates are a little less enamored with the "WOW" factor of LASIK — and more safety-minded — and thus more inclined to opt for surface ablation. In addition, many surface ablation advocates believe that wavefront surface ablation produces better visual outcomes than wavefront LASIK.

Surface Treatment of Choice

Dr. Claringbold, of the Mid-Michigan Physicians Group in Clare, Mich., who has long been a champion of surface ablation, now performs epi-LASIK on approximately 80% of his refractive patients.

"I still do LASEK for some patients, such as those who are post-cataract, but I find epi-LASIK a better procedure because you eliminate the alcohol that you have to use in performing LASEK," he says.

"With epi-LASIK, we are now closing the gap on LASIK in terms of improving the patient experience. I found that LASEK requires about a week of recovery time," Dr. Claringbold continues. "My epi-LASIK patients are much more functional during the first week postop and some are quite functional after 1 day."

Dr. Claringbold envisions a time when epi-LASIK accounts for the majority of all laser vision correction procedures in the United States, as it currently does in Europe.

"Surface ablation has always been popular in Europe because the European culture does not put as high a priority on instant gratification as our culture does," Dr. Claringbold notes. "They have a slower lifestyle and tend to choose the safer surface procedure even if it means a little longer recovery time."

Some Surgeons Use it More Selectively

While Drs. Claringbold, Milne and McDonald have moved almost exclusively to epi-LASIK and surface ablation, Drs. Donnenfeld, Soloway and Azar still perform LASIK on a majority of their patients.

"I'm still a big believer in LASIK," says Dr. Donnenfeld of Ophthalmic Consultants of Long Island. "I'm currently performing epi-LASIK on about 10% of my refractive patients but I expect that to increase to approximately 20%. I favor epi-LASIK for patients with irregular topographies who would be at risk for ectasia with LASIK. I also favor epi-LASIK for patients who have a history of dry eye."

Dr. Donnenfeld believes that the development of multi-faceted pain-reduction regimens over the past few years has removed one obstacle to patients' acceptance of epi-LASIK.

"Pain is no longer the issue with epi-LASIK," he says. "What surgeons are focusing on now is achieving faster visual recovery and healing."

Dr. Soloway, director of vision correction at the New York Eye and Ear Infirmary, is currently performing surface treatments on about one-third of his refractive patients, with epi-LASIK his procedure of choice.

"I prefer to perform a surface treatment if a patient has a pachymetry issue, a history of dry eye, or simply if the patient prefers what I consider a safer procedure," says Dr. Soloway. "I think with epi-LASIK we are closing the gap on the pain issue compared to LASIK, but I don't think we are quite there yet. I will say that with my epi-LASIK patients, after 24 hours the pain is pretty much gone."

The Flap Issue

Though all of the surgeons interviewed for this article generally agree on such epi-LASIK issues as appropriate patient selection and effective pain-reduction regimens, one area of minor disagreement on how epi-LASIK should best be performed is still being studied. That is the question of whether the intact epithelial flap should be used as a natural bandage or be discarded. The issue is of such interest that Drs. Donnenfeld, Soloway, Milne and Azar all have conducted their own studies on just this point.

One of the more ambitious studies was conducted by Dr. Milne of the Eye Center in Columbia, S.C., who performed 50 epi-LASIK procedures in which he left the intact epithelial flap on as a natural bandage and then 50 more procedures in which he discarded the flap.

"My study convinced me that there are definite advantages in discarding the flap," says Dr. Milne. "The biggest advantages are in terms of faster visual recovery and healing, which are of major importance to patients. When I discard the flap, 95% of my patients can drive and get back to work within three-and-a-half days, which means that they can have the surgery on a Thursday after work and be back at work with no pain and fully functional vision by Monday morning. Compare that to PRK which takes about a week to heal."

Dr. Milne says that when he left the epithelial flap on, a small percentage of his epi-LASIK patients experienced delayed visual recovery.

"My belief is that when you leave the flap on, new epithelium grows over the old epithelium and you get a "skin-on-skin" effect that can delay visual recovery," he says.

Advocates of leaving the epithelial flap on as a natural bandage after epi-LASIK assert that the presence of the flap diminishes pain and reduces the chances of the patient developing haze.

The Haze Issue

Dimitri Azar,, M.D., field chair of ophthalmic research and head of Ophthalmology and Visual Research at the University of Illinois at Chicago, has conducted an animal study on the haze issue. He found that retaining the flap is the best way to prevent haze from developing after epi-LASIK.

"If the epithelial flap is intact and it adheres, I will put it back over the eye," says Dr. Azar. "If the epithelial sheet is torn, which happens very rarely, I will convert the procedure to PRK or possibly LASEK. I'm open-minded and would like to see further studies on this issue, but as of now I see no reason for throwing a viable epithelial flap away."

"If the flap is healthy and intact, I prefer to leave it on," adds Dr. Soloway.

"We conducted a contralateral study with epi-LASIK patients in which we left the flap on one eye and discarded the flap from the other eye," Dr. Soloway continues. "The differences were not huge, but patients reported slightly less pain in the eye with the flap and we found a slightly smaller chance of developing haze when the flap is retained. Visual recovery may be a bit quicker if the flap is discarded, but we place a higher priority on patient comfort and pain reduction."

Dr. Milne is aware of the widespread perception that discarding the flap creates a greater chance of the patient developing haze, but he believes that he has effectively negated the haze issue by using mitomycin C (MMC) 15 to 20 seconds after the surgery is completed for all patients who have an ablation depth of more than 75 microns.

"I have not seen a single case of haze in any of these patients," says Dr. Milne.

No one disputes Dr. Milne's findings, but some surgeons, including Dr. Soloway, prefer not to use MMC for their refractive patients because they believe that in isolated cases it can slow the healing process.

Dr. Donnenfeld comes down on the side of discarding the epithelial flap. He calls this variation of epi-LASIK lamellar epithelial debridement.

"We have found that, with lamellar epithelial debridement, both vision recovery and healing are faster," says Dr. Donnenfeld. "But whether you retain the flap or discard it makes no difference in long-term visual outcomes."

Small Disagreements, but a Single Goal

One thing to remember is that even though these surgeons may disagree on specific points, they are all advocates of epi-LASIK and are working to make the procedure as safe, effective and patient-friendly as possible.

"Epi-LASIK is meeting with growing acceptance and continues to become a more appealing option," concludes Dr. Azar. "When it is done well, it can be an elegant and predictable procedure."