Femtosecond Laser Offers Flapless Refractive Corneal Surgery

A minimally invasive laser technique allows the correction of refractive errors by creating a lenticle inside the intact cornea, which is then removed through a small incision.

The ReLEx smile correction technique for refractive errors requires an 80% smaller surface incision in the upper cornea--the flap-side cut--and a 30% smaller lamellar incision on the cap cut surface. As a result, the biomechanical stability of the vital upper layers of the cornea remains largely intact, resulting in a gentle, minimally invasive operation. And with minimized severance of nerve pathways, the technique results in a lower occurrence of dry-eye syndrome, which is a common side effect of laser procedures. The diopters (D) treatment range of the technique is -0.5-10.00 D (sphere), 0-5.00 D (cylinder), and -0.75-10.00 D (spherical equivalent).


A single femtosecond laser, the Carl Zeiss Meditec (Jena, Germany) VisuMax is used to cut (rather than ablate) the tissue inside the intact cornea, resulting in a procedure that is more independent of intraoperative ambient conditions. With the lenticle and access created in a single treatment step, predictability is improved, which is beneficial with high refraction values of up to -10 diopters. Because the entire refractive correction takes place using VisuMax, the patient does not have to be moved to another laser system, and doctors also benefit from shorter treatment times, since creating the lenticle takes just a little bit longer than a simple flap incision.

“The ReLEx smile minimally invasive treatment method is pioneering and has the potential to herald a paradigm shift in refractive laser surgery,” said Ludwin Monz, PhD, MBA, president and CEO of Carl Zeiss Meditec. “Carl Zeiss thus establishes another milestone in refractive corneal surgery.”

Femtosecond lenticle extraction is a new form of refractive eye surgery that creates a lenticle for removal and a corneal flap. It uses a single femtosecond laser--compared with two laser used in laser-assisted in situ keratomileusis (LASIK)--to cut a lens-shaped layer (the lenticle) from within the cornea and shape it to achieve improved patient vision. The surgery is reversible in many cases, helping those who develop long-sightedness or presbyopia as they age.

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