Washington, DC — As refractive surgeons are revisiting surface ablation, the EpiLift System (Advanced Refractive Technologies/VisiJet) offers an advanced approach incorporating safe, simple, and precise mechanical epithelial separation.
April 18 - Washington, DC - As refractive surgeons are revisiting surface ablation, the EpiLift System (Advanced Refractive Technologies/VisiJet) offers an advanced approach incorporating safe, simple, and precise mechanical epithelial separation.
In a Sunday evening symposium sponsored by Advanced Refractive Technologies, foreign and U.S. experts on surface ablation reviewed the potential benefits of epi-LASIK and the EpiLift system and outcomes achieved in their clinical and laboratory studies.
Dimitri Azar, MD, who is regarded as a pioneer in advanced surface ablation, reviewed the results of experiments he performed establishing that application of alcohol, such as is used in LASEK, is associated with variable effects on epithelial cell viability and morphology. The attraction of epi-LASIK is that it avoids cutting through Bowman's membrane as well as the cytotoxic effects of alcohol exposure, he said.
Moderator Terrence O'Brien, MD, told attendees that while epi-LASIK itself is a procedure in evolution, users of the EpiLift system have found it can reliably separate the epithelium mechanically without the need for alcohol.
"This instrument performs in the great tradition of German precision-engineered equipment," he said.
Ron Krueger, MD, shared findings from histology studies he has performed showing absence of incursion into the stroma using the EpiLift system. His results showed that EpiLift flap creation was associated with epithelial flap and stromal integrity along with presence of intact intercellular adhesions near the basal epithelial cells. Notably, Bowman's membrane was also generally intact except for some microfocal disruptions.
"In the future we will be especially interested in evaluating whether preservation of Bowman's membrane with this procedure translates clinically into faster epithelial healing and reduced risk of haze," Dr. Krueger said.
Several speakers shared their initial clinical experience with the EpiLift procedure, which can be summed up as being very favorable overall.
Dr. O'Brien presented results on behalf of Tom Claringbold, MD, from an early series of 50 eyes treated for myopia with or without astigmatism. Preoperative SE for the group ranged from -1.25 to -8D, and no intraoperative mitomycin-C was used, even in the higher myopes.
Dr. Claringbold encountered no flap complications or stromal cuts and achieved 20/40 or better UCVA in 92% of eyes on day 4 postoperatively. By 2 weeks, 92% of eyes had 20/25 or better UCVA and at 3 months when 36 eyes were seen, UCVA outcomes were further improved and 97% of eyes were corrected to within 0.5 D of intended.
Lt. Col. Scott Barnes, MD, reported results of a contralateral eye controlled study comparing the EpiLift procedure versus LASEK. With 2 months of follow-up available so far in 45 patients who underwent uneventful epithelial flap creation in both eyes, visual acuity results and pain scores have been similarly favorable.
Dr. Barnes and other speakers indicated there is some learning curve for novices to the epi-LASIK procedure, although it is not steep. He noted that while he encountered flap creation problems including suction problems and partial flaps in several eyes early on, the procedures were converted to PRK and visual outcomes in those eyes have been comparable to those who had uncomplicated flap creation in LASEK or epi-LASIK
Increased experience and some minor modifications in technique have largely addressed those problems. However, Dr. Barnes pointed out that his study reflects his initial experience with the EpiLift procedure. In contrast, he has performed about 2,000 cases of LASEK.
"When the EpiLift procedure works well, it's great, and it works well most of the time. However, I think any refractive surgeon can undertake this procedure very comfortably knowing that it offers excellent safety," he said.
Pain has been an issue early on in epi-LASIK, but advances are being made to address that as well. Kerry Assil, MD, has been refining his peri- and postoperative management regimen to minimize pain so that patients who undergo epi-LASIK can have the same comfort level associated with LASIK. While his technique is still evolving, pain seems to be less of a problem for epi-LASIK patients than it is postPRK, Dr. Assil said.
Furthermore, considering its safety profile, Dr. Assil said his own intraoperative "anxiety level" is lower during epi-LASIK with the EpiLift system compared with any other refractive procedure he performs.
"I have gravitated toward epi-LASIK and consider it one of the most exciting new advances in refractive surgery," he said.
Bruce Larson, MD, reported good success applying chilled BSS immediately prior to flap creation. In a series of 40 eyes representing his and Dr. Claringbold's pooled experience with that approach, no patient has had a postoperative pain score higher than 1 on a scale of 0 to 10.
"More patients need to be studied, but I am very excited about this development because pain was one of the major barriers to the epi-LASIK procedure," he said.
Dr. Larson also shared the modifications he has made over time in his technique for using the EpiLift system and for handling the flap. With those developments, he has successfully minimized suction breaks and flap stretching, and has seen benefits clinically in terms of faster visual recovery and reduced corneal epithelial edema.
Looking toward the future, Dr. O'Brien proposed that because the EpiLift procedure does not cut across stromal collagen and avoids lamellar flap-induced higher-order aberrations, it has the potential to marry nicely with wavefront guided customized treatment.
"Clearly, it offers an improved technique that affords the advantages of LASEK while eliminating the disadvantages of LASIK, and many surgeons are now evaluating this as a procedure to use with customized ablations to reduce aberrations," he said.