Better Diagnostic Tool for Retinal Diseases Under Development

The University of Houston College of Optometry is taking part in a National Science Foundation funded initiative to coordinate the efforts of researchers across the country working in the rapidly developing field of adaptive optics, which has major applications in astronomy and vision science.

The initiative is being spearheaded by the University of California at Santa Cruz under the auspices of its soon-to-be operational Center for Adaptive Optics, which will have participation from 27 partner institutions, including UH. The NSF program guidelines allow financial commitments of up to $20 million over five years, subject to negotiations between NSF and UCSC.

UH assistant professor of optometry Austin Roorda's project focus is in the area of vision science. He is currently in the early stages of developing a scanning laser ophthalmoscope that uses adaptive optics. Adaptive optics is a method to actively compensate for changing distortions that cause blurring of images. It is used in astronomy to correct for the blurring effect of turbulence in the earth's atmosphere and in vision science to compensate for aberrations in the eye that affect vision and impede efforts to study the living retina.

"This new scanning laser ophthalmoscope will be designed to produce sharper images of the retina," says Dr. Roorda, "and provide high contrast views of the various structures - like blood vessels, photoreceptors, nerves and other cells - that constitute the human retina." The instrument would produce a three-dimensional view of the retina, he adds.

An adaptive optics system requires several highly advanced technologies, including precision optics, sensors and deformable mirrors, plus high-speed computers to integrate the whole system. The system uses a point source of light as a reference beacon to measure precisely the imperfections in the cornea and lens, which form the optical system. An adaptive optical element, usually a deformable mirror, is used to cancel the effect by applying an opposite distortion.

Experts say although adaptive optics were suggested in the 1950s, only today are the requisite technologies mature enough to make an important impact on vision science and astronomy.

Dr. Roorda says while scanning laser ophthalmoscopes have already existed for about a decade, their ability to look at the layers of the retina is limited by the aberrations of the eye. "Through adaptive optics, having a better view of the retina can allow for better diagnoses of retinal diseases. What it boils down to is that if you can see something better, you ought to be able to diagnosis it more effectively."

And with adaptive optics, the Keck Telescopes, currently the largest optical telescope in the world, can achieve four times the resolution of the Hubble Space Telescope in the near-infrared wavelengths, experts say. The UCSC's Center for Adaptive Optics is expected to sustain efforts needed to bring adaptive optics to widespread use.

Dr. Roorda expects the new scanning laser ophthalmoscope to be completed by fall 2000.

- TANYA DEASON-SHARP

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©2006 Texas Medical Center

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