By Patricia Daukantas

OSA Fellow Jim Wynne could be resting on his laurels for his role in developing laser ophthalmic surgery. Instead, he’s working on a new idea: using lasers to excise dead tissue from the wounds of burn victims.

Wynne, who works at IBM Corp.’s Thomas J. Watson Research Center, attended yesterday’s laser exhibit and demonstration on Capitol Hill in Washington, D.C. He and a Maryland ophthalmologist, Sonny Goel, were there to discuss laser eye surgery techniques such as laser-assisted in situ keratomileusis, or LASIK. As I recounted on this blog a few months ago, Wynne discovered the excimer laser’s ability to remove tissue cleanly without damage to the surrounding tissues, and that realization led to the wonders of ophthalmic refractive surgery.

For years, Wynne and his tennis buddy, dermatologist Jerome Felsenstein, have been batting around the idea of using a laser to debride the charred, dead layers of skin from the wounds of severely burned people. Currently, surgeons need to do this with a scalpel. Wynne and the dermatologist were trying to figure out how to get the advantages of extremely clean tissue removal without making the procedure take way too much time.

The answer, according to IBM’s recently filed patent application, is to use two ultraviolet lasers in a sterile, self-terminating procedure. One laser, operating at 308 nm, would act like rough sandpaper and remove a lot of the dead tissue quickly. The second, with a wavelength of 192 nm, would carefully clean off the last little bit of dead tissue and stop “when it hits salt water” or living tissue, Wynne said. (As he explained, the 192-nm light is close to a strong absorption line of chlorine ions, so when the light encounters the slightly salty liquid of living tissue, the energy goes into changing the Cl^– ions into neutral Cl atoms instead of heating the proteins in the skin.)

Wynne stressed that there’s one major caveat: This technique has not yet been tried on living animals (including people). But he showed me photos of an experiment performed on pigskin from a butcher shop. Wynne and his colleagues burned sections of the pigskin to a crisp with a blowtorch, and then they used the two lasers to remove the blackened surface of epidermal tissue and reveal the non-charred layers underneath. According to Wynne, the animal studies cannot be done at IBM, so he’s working out a partnership with one of the trauma surgeons at Brigham and Women’s Hospital in Boston (Mass., U.S.A.). They’re still seeking funding and equipment.

Wynne hopes that this technique – if it turns out to work on living patients, which is still not a given – could improve treatment of wounded soldiers in the field. The mobile medical unit could take off the necrotic outer layers of tissue before infections and fungi take hold, and then the patients could be airlifted to a burn center for skin grafts and treatment of their other injuries.

Finally, Wynne pointed out with pride this article from Ocular Surgery News, which provides compelling evidence that the benefits from LASIK and photorefractive keratectomy (PRK) are not just cosmetic: for members of the U.S. armed forces, who can’t wear contact lenses on the battlefield, the procedures mean a chance at a career track closed to the nearsighted – and can be life-saving for soldiers captured or caught on the battlefield without their eyeglasses.

It was great to meet Jim Wynne in person and pick up on his enthusiasm for doing science and inspiring others to pursue science. Since 1990, Wynne has been IBM’s program manager for local education outreach, and for most of that period he’s been getting IBM employees and high school students to volunteer at family science programs aimed at third- through fifth-graders. We wish him all the best with these educational efforts and look forward to hearing more about the laser-debridement experiments in the future.

2010-04 April, Biomedical optics, Lasers, Ophthalmology fellows, laserfest, lasers, opthalmology, surgery, biomedical optics, laser ophthalmic surgery

By Patricia Daukantas

First, it was an expensive dream. Next, it was the butt of worldwide jokes – nearsighted and rhyming with “trouble.” Today, though, the Hubble Space Telescope (HST) is an indispensable instrument in the toolboxes of astronomers, and they are celebrating the 20^th anniversary of its ride into Earth orbit.

NASA’s space shuttle Discovery carried Hubble into orbit on April 24, 1990. Already by then, the telescope idea had been on a long and complex path to realization.

Princeton University astrophysicist Lyman Spitzer Jr. (1914-1997) had been pointing out the advantages of an extraterrestrial observatory as far back as 1946 – more than a decade before the launch of the first space satellite. The astronomical community fought back against budget cuts for years until construction funding was approved in the late 1970s. After cost overruns, Hubble was nearly ready to go by January 1986, when the shuttle Challenger‘s accident grounded the remaining shuttles and forced a long postponement of Hubble’s launch.

Once Hubble got off the ground, of course, reports of the primary mirror’s spherical aberration made headlines all over the planet. (These reports surfaced in late May and early June – I’ll bet that nobody at NASA will be commemorating that 20^th anniversary.) Fortunately, some of the brightest minds in optical science – including more than a few OSA members – got to work on the Independent Optics Review Panel and set to work on designing a package of corrective optics for the orbiting telescope. Installing the corrective instrument, dubbed COSTAR, was the top priority of the first Hubble servicing mission in the fall of 1993.

OPN covered this story with several articles. We devoted much of the November 1993 issue to the Hubble rescue effort, with such articles as “Engineering the COSTAR” and “Optical Testing and Verification on HST.” In the August 1994 issue, representatives of a NASA subcontractor, Tinsley Laboratories, wrote about their production of the corrective optics that were then integrated into the instrument package built by Ball Aerospace.

Astronomers cheered when they saw the first crisp, clear Hubble images of a nearby galaxy following that first servicing mission. The Hubble discoveries made in the last 16 years are way too numerous to summarize in any blog post.

This weekend, you can celebrate Hubble’s 20^th anniversary by visiting NASA’s commemorative page or the Hubble public information site. You can join in the Hubble pop culture contest, “friend” Hubble on Facebook, send a congratulatory message on Twitter.com with the hashtag #hst20 or even help astronomers classify galaxies found on real Hubble images with the Galaxy Zoo: Hubble project.

Happy 20^th Birthday, Hubble, and we hope you’re still active to celebrate your 25^th!

2010-04 April, Astronomy, Astrophysics astronomy, hubble, optics, space telescopes, telescopes

By Patricia Daukantas

For the past year, “citizen scientists” have been observing the behavior of an unusual double star to gain insight into its mysterious eclipses. Recently, a team of professional astronomers used optical interferometry to catch the first glimpse of the dimmer star that eclipses its brighter companion every 27.1 years.

As we’ve blogged in the past, the star system Epsilon Aurigae has been the subject of an intensive observing campaign this year. Several of the professional astronomers behind the “citizen sky” project have now seen that the eclipsing object is a large, slightly tilted disk surrounding a single, hot star. The team reported its results in the April 8 issue of Nature.

It turns out that the central star of the pair is a F-type star, slightly hotter than our Sun and with up to three times its mass, and its eclipsing companion is an extremely hot B-type star, shrouded in dust warmed to about 550 K. But how do Robert Stencel (University of Denver, Colo., U.S.A.) and his colleagues know that?

As it turns out, they imaged the Epsilon Aurigae system with the CHARA array of six telescopes on Mount Wilson in California. (CHARA stands for the Center for High Angular Resolution Astronomy, located at Georgia State University in Atlanta.)

With apertures of only 1 m, the six CHARA scopes are tiny by professional standards. However, they are positioned over the mountainside to provide the resolving capability of a much larger single telescope – up to 331 m wide (that’s the array’s longest baseline). Radio astronomers may have been the first to use interferometry to boost the amount of detail we can see in the heavens, but optical (visible and infrared) astronomical interferometry has come of age in recent years – see this post about another interferometer on Mount Wilson, used by OSA Honorary Member Charles Townes and colleagues to study the size of the red giant star Betelgeuse.

For more information on CHARA and optical interferometry, see this PDF presentation or the CHARA website. For additional coverage of Epsilon Aurigae, see the U.S. National Science Foundation announcement or this article from Sky & Telescope magazine.

And don’t forget … the Citizen Sky website is still collecting observations of Epsilon Aurigae, and anyone can make them regardless of equipment (or the lack thereof). This makes a great class project.

2010-04 April, Astronomy, Astrophysics amateur astronomy, astronomy, interferometry, citizen sky, astrophysics, optical interferometry