Keraflex is Avedro's patented and proprietary, non-invasive refractive correction procedure that gently reshapes the cornea. Because it is non-incisional and non-invasive, Avedro believes Keraflex will be the first refractive correction procedure to preserve the cornea's bio-mechanical integrity. Keraflex is expected to overcome current barriers to the broader adoption of laser vision correction, especially fear of undergoing eye surgery among low and moderate myopes. Refractive correction and the preservation of the biomechanical integrity of the cornea are also proving to be of importance in the treatment of keratoconus.

April 22, 2010
Avedro receives CE mark for system to perform Keraflex procedure.
WALTHAM, Mass. — Avedro announced that its Vedera system for performing the Keraflex corneal flattening procedure received the European Union's CE mark, according to a press release from the company.   "I am pleased by how quickly Avedro has been able to transform its thermo-biomechanics platform technology into a commercially available ophthalmic device," David Muller, PhD, Avedro president and CEO, said in the release. "Avedro has been conducting clinical trials to treat myopia and keratoconus with the Keraflex procedure and is extremely pleased with the results. CE mark certification is an important milestone for the company and also represents a vital new offering to ophthalmic patients and their physicians."

Keraflex® and the Vedera™ KXS
This non-incisional procedure expands the eligibility criteria for people seeking refractive correction and overcomes the current barriers to broader adoption of laser vision correction, especially among people with low and moderate myopia.

In the treatment of keratoconus, preservation of the biomechanical integrity of the cornea and the ability to effect refractive change similarly hold promise for improving disease management.

The Keraflex® procedure, performed with the Vedera™ KXS, is currently in clinical trials in Europe for the correction of myopia and other refractive disorders, and for the treatment of keratoconus. Avedro plans to file for an FDA IDE in the United States in mid-2010.

The Vedera™ KXS and the Keraflex® Procedure
During a Keraflex® procedure, the Vedera™ KXS delivers a single low energy microwave pulse lasting less than one second. Energy is applied to the cornea using a dielectrically shielded microwave emitter which contacts the epithelial surface. Through capacitive coupling, the single pulse raises the temperature of the selected region of corneal stroma to approximately 65°C, shrinking the collagen and forming a toroidal lesion in the upper 150 microns of the stroma.

Using an evaporative cooling technique (patent pending), the Vedera KXS cools the surface of the cornea during the treatment to isolate and protect Bowman’s membrane from the thermal effects of the microwave energy. The lesion created during Keraflex is intended to flatten the central cornea to achieve myopic correction without compromising the biomechanical integrity of the cornea.

The amount of induced refractive change achievable with the Vedera KXS is a function of lesion diameter and cross-section. Avedro has developed Keraflex Applicators with varying diameter emitters to provide the capability to create a range of lesion diameters when performing the Keraflex procedure.

Depending on the amount of energy delivered by the Vedera KXS and the choice of Keraflex Applicator, tissue lesions of differing dimensions and geometries can be created.

Avedro uses a proprietary sterile, disposable, BioInsulator™ for the dielectrically controlled transmission of the microwave energy; safe and efficient cooling of the eye; and protection against cross-contamination during each Keraflex procedure.The Vedera KXS, for performing the Keraflex procedure, is a CE marked product.

The Keraflex procedure is designed to flatten the cornea to correct myopia and reverse keratoconus. The noninvasive procedure thermally alters the tension of collagen fibers in the cornea without the need to remove tissue. It alters refraction without compromising the cornea's biomechanical integrity, the release said.

Targeting Stage
The Targeting Stage is used to position the applicator over the appropriate Keraflex® treatment zone. It is placed onto the eye and suction is engaged. An alignment reticle is inserted into the targeting stage and by using the alignment knob, the center of the treatment zone can be precisely adjusted in the X and Y axes.




Applicator
Keraflex Applicators with varying diameter electrodes enable the creation of a range of lesion diameters when performing the Keraflex procedure.




BioInsulator™
Avedro’s BioInsulator allows for the dielectrically controlled transmission of the microwave energy, safe and efficient cooling of the eye, and protection against cross-contamination during each Keraflex procedure.

Keraflex® KXL is currently in clinical trials in Europe for the treatment of keratoconus (KC), a degenerative disorder which causes the cornea to thin and bulge from its natural state to a conical shape resulting in distortion of vision. There are limited therapeutic options for treating KC, and currently there is no established treatment option for high diopter refractive correction among KC patients, which is a prevalent need.

On average, the onset of KC begins at 16 years old and afflicts millions of teens and young adults around the world, severely affecting their visual acuity and often requiring cornea transplants, up to 5,000 each year in the US alone. Cornea transplants require up to a year for full visual recovery and approximately 40 percent will require a regraft within 10 years.

Early clinical results suggest Keraflex KXL flattens the protruding cone of keratoconus and makes the irregular cornea smoother, thereby improving visual acuity. Adjunctive selective collagen cross linking is expected to enhance the induced refractive effect as well as stabilize the keratoconic cornea.

In addition to the possibility of improved visual acuity, Keraflex KXL holds the potential to increase tolerance to contact lens wear and to improve vision correction with glasses among KC patients. Further, this non-invasive procedure may ultimately help KC sufferers, with no alternative therapeutic options, avoid cornea transplants or at least delay the progression to transplant.

Images courtesy of Pacific University, Oregon, USA