Telescope technology to diagnose eye diseases

Adaptive optics, a technique developed by astronomers to produce pictures of stars, can image the minute details of our eye balls. The resulting 3D images can help detect diseases sooner.
Written by Janet Fang, Contributor

Turns out, the twinkling of stars is not all that different from the twinkle in your eye.

A technique originally developed by the military and used by astronomers now allows researchers to diagnose eye diseases much sooner than current methods can. Popular Mechanics reports.

When ophthalmologists and vision scientists look into our eyes, distortions within the cornea and lens impair light as it travels through the eyeball, frustrating their efforts. But lately, they’ve turned to adaptive optics, a solution pioneered by astronomers to produce clear images of faraway stars.

When stargazing, distortions in the atmosphere such as turbulence and wind shear create that twinkling effect. When you look through a telescope, there's no twinkle – just a big blur. So adaptive optics uses a device called a wave-front sensor to detect the degree to which light has been distorted as it approaches the telescope.

To make this work out correctly, telescopes such as Hawaii's Keck Observatory use a guide star, which astronomers create by aiming a laser into the upper atmosphere. When tuned to the right frequency, the laser excites sodium atoms leftover from meteorites that have condensed in a layer atop the mesosphere, about 60 miles up. Excited sodium atoms then send light back toward the telescope, which can be measured by observatory's wave-front sensor. This information is then continuously fed to a computer that precisely bends an intricate mirror to adjust for and cancel out these distortions.

Applied to the human eye, scientists could shine a laser onto the back of the retina, which functions as a weak mirror. That light spot is then used to measure and adjust for the imperfections in the focusing optics of the eye.

The technique allows researchers to view minute details never before seen and to diagnose diseases – like age-related macular degeneration and glaucoma – months to years sooner than our current methods allow.

David Williams from University of Rochester was the first to do this, back in the 1990s. Building on this work, astronomer Scot Olivier at Lawrence Livermore National Laboratory teamed up with vision scientists John Werner of UC Davis and Indiana University’s Donald Miller to create more advanced imaging prototypes.

Combining adaptive optics (to see minute details) with another technique called optical coherence topography (to measure tissue thickness), the team was able to produce 3D images of cells within the retina – such as light-sensing photoreceptors – something that’s not possible with other technologies.

So far, 3 prototype imaging devices have been made, 2 of which are used to diagnose disease among eye patients in California and Indiana.

[Via Popular Mechanics]

Image by JD Hancock via Flickr

This post was originally published on Smartplanet.com

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