According to a recent report from Popular Mechanics, a technique originally designed for the viewing of distant stars is being used by researchers to diagnose eye problems months or years sooner than thought possible.
When eye practitioners and ophthalmologists examine the eye head-on, distortions in the cornea and lens hinder the light used by doctors to view the inner eye.
However, adaptive optics – developed by the military and used by such institutes as the Lawrence Livermore National Laboratory to examine stars – is being used by a core group of scientists to look into early signs of vision loss. The technology affords scientists insight into very fine, miniscule details that have never been seen before, allowing them to diagnose eye problems long before more symptoms arise.
David Williams, a vision scientist from the University of Rochester, had the idea to use adaptive optics to look into the human eye in 1990. He figured that scientists could shine a laser about 1,000,000 times weaker than that used to look at stars onto the human retina.
This spot illuminated by the laser would be used to measure for imperfections in the eye’s focusing optics.
Adaptive optics involve shining a laser into the upper atmosphere and tuning it to a specific frequency. At the right frequency, the laser excites sodium atoms, left behind from meteorites, that have gathered in a layer above the mesosphere. The atoms reflect light back toward the telescope, and the wave-front sensor measures this light. The data is fed to a computer, and this in turn adjusts a mirror that cancels out distortions.
As adaptive optics only allow for the production of 2D images, the group of researchers fused it with a different technique called optical coherence topography. This means that 3D images of retinal cells, like cone photoreceptors, can be created. The researchers, funded by the National Institutes of Health and the National Eye Institute, have made three prototype machines currently being used to diagnose patients in California and Indiana.
Scientists say that eye afflictions such as epiretinal membrane and macular holes have already been found with this new technology. They intend to be able to spot macular degeneration long before its major symptoms begin to show, as well.
“It’s great to see the same tricks developed in astronomy being used to solve problems in vision science,” says astronomer Scot Olivier, of California’s Lawrence Livermore National Laboratory.