Avedro Using Microwave Technology to Change Shape of Cornea to Correct Vision

May 12, 2009

I recently read a story that came out of the April ASCRS Meeting held in San Francisco. It concerned research being conducted by Dr. John Marshall and his colleagues at King’s College in London were trying to use of microwave energy to flatten the corneal curvature in a form of refractive correction.

Marshall reported that his group had hypothesized that the use of microwave energy could be targeted to “shrink” stromal collagen fibrils, both superficially and centrally within the cornea to correct myopia. This use of targeted microwaves could also be used in a peripheral ring to induce steepening of the cornea to correct hyperopia.

As I read the report, I was reminded that I had written about this very same thing nearly 20 years ago, in a “Technology Update” column written for Ophthalmology Management in October 1990. That column was titled, “The Rebirth of Thermal Keratoplasty (TKP)”, and told the story of Dr. Bruce Sands and his company Laser BioTech (which later licensed the technology to  Sunrise Technology) trying to use targeted holmium laser energy to shrink collagen fibers, without thermal trauma, to flatten the cornea.

As background to this story, I also wrote about earlier attempts to use microwave energy to do the same thing, by a group that included Ralph Crump of Frigitronics (developer of the Softcon Lens – later licensed to American Optical) and Stuart Trembly of Dartmouth College. They were issued a patent that disclosed the use of microwave energy to shrink collagen tissue.

Nothing came from the microwave effort, and Sunrise Technology’s laser was marketed for a short time but the lack of precision in the shrinkage of collagen and a loss of effect lead to its demise.

The only company to take advantage of precise collagen shrinkage has been Refractec, with its Viewpoint CK conductive keratoplasty technique. This technique uses short pulses of radio-frequency energy introduced into short metal probes inserted into the cornea in a tight pattern for the correction of hyperopia.

Well, apparently there is a new company, founded by David Muller, the former CEO of Summit Technology and the above mentioned Stuart Trembly, called Avedro Inc. that is using microwave technology to successfully change the cornea’s shape for correcting vision.

According to a recent filing with the U.S. Securities and Exchange Commission, the firm has raised an additional $10 million of equity venture capital funding to go along with its initial financing of $8 million.

Avedro’s technology, called Keraflex, uses focused energy to reshape the front surface of the cornea. Avoiding the creation of a flap in the cornea or the need for the removal of any corneal tissue.

Clinical trials will start shortly, followed by product launch in Europe.

As I learn more about this effort, I will report it in this space.

To read more about what I wrote in 1990, please see my column, reproduced in my Online Journal.




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One Response to “Avedro Using Microwave Technology to Change Shape of Cornea to Correct Vision”

  • Reproducabiltiy assumes a uniform density and hydration and perfect delivery. The thermal effect that leads to shrinkage must by nature of what is known from CK and the more superficial Sunrise Holium treatment be deep and over shoot the mark to account for relaxation that ALWAYS occurs.
    I think we have little to be interested in here. I hope we do no harm in these VC manipulators working their trade on our patients.