EpiVision System considered an advance in surface ablation

March 18, 2006

Epi-LASIK with the EpiVision System (CooperVision Surgical) is a definite advance in surface ablation techniques for refractive surgeons, according to surgeons experienced with the device.

Epi-LASIK with the EpiVision System (CooperVision Surgical) is a definite advance in surface ablation techniques for refractive surgeons, according to surgeons experienced with the device.

The EpiVision System, manufacturered by Gebauer, is used to create a viable epithelial flap with an intact Bowman's membrane prior to surface ablation. The device has a metal blade with defined geometry for separating the epithelium and a bar applanator for leveling the cornea, allowing for a smooth separation of the epithelium.

"We can separate the epithelium to allow for uniform surface ablations with this special device," explained Terrence O'Brien, professor of ophthalmology and director of refractive surgery and co-director, Bascom Palmer Eye Institute, Miami. He spoke about evolving approaches to surface ablation during a breakfast session at the American Society of Cataract and Refractive Surgery annual meeting. "It really partners well with wavefront-guided customized treatments."

Surgeons might consider Epi-LASIK for patients with thinner than normal corneas (pachymetry less than 500 microns), high myopia to save corneal tissue, flat corneas, topography that may indicate subclinical or form fruste keratoconus, small palpebral openings, pre-existing dry eye, glaucoma, endothelial cell dysfunction, and fear of stromal flap creation, Dr. O'Brien noted.

There are a few issues to resolve associated with Epi-LASIK before more surgeons will adopt this technique, he said.

"Pain is still an issue that we need to gain control of. We need a uniform experience similar to our LASIK patients. We need rapidity of visual rehabilitation-days not weeks of recovery," explained Dr. O'Brien. "We also need longer term higher-order aberration analysis."

Haze is a concern in surface ablation techniques and possibly depends on the degree of refractive error, shape and depth of the ablation, smoothness of the ablations, and patient age.

"Also, whether one needs to use any adjunctive agents (such as mitomycin C) is up for debate," Dr. O'Brien said.

"We are seeing an increase in the adoption of Epi-LASIK. I am using this technique in 35% of my patients," he said.

Dimitri Azar, MD, also offered a historical perspective and future outlook for surface ablation. He noted the following advantages of Epi-LASIK including a viable alternative to LASIK, especially for young patient with thin corneas and/or steep Ks; avoidance of microkeratome and flap-related complications; and an alternative to phakic IOLs for patients with low endothelial cell counts, shallow anterior chamber, early lens opacities, or high astigmatism.

He noted the main limitation of Epi-LASIK, the unknown long-term risk of prophylactic use of mitomycin-C to prevent haze.

Thomas Claringbold II, DO, discussed his early experience with Epi-LASIK using the EpiVision System on 50 eyes without mitomycin-C. He found that preoperative use of vitamin C (1,000 mg daily) given 3 weeks prior to the procedure and then continued for 3 to 4 months after has helped with haze prevention. For pain control, he uses celecoxib (Celebrex, Searle) 200 mg daily starting 72 hours before the surgery and frozen balanced salt solution during the surgery. Patients continue the celecoxib after the surgery.