University of Houston researchers are using a technology called adaptive optics to peer inside the eyes of human subjects and for the first time get clear, sharp images of features such as blood flow in the eye's retina. Until now, clear images of the living retina were not possible because the eye's own structure interferes with the imaging process. "Everyone suffers from natural irregularities in the cornea and lens of the eye, and even in people with normal, 20/20 vision, these defects prevent the eye from focusing light from the world into a nice sharp image on the retina," says Austin Roorda, assistant professor of optometry at the University of Houston. "Eye doctors have to look through these same defects when they examine a patient's retina, and the image they see is not very clear, limiting the amount of information they can get."
A clear view of the retina is key to the early diagnosis of diseases such as glaucoma, which produces changes in the nerves in the eye, and diabetes, which affects blood flow in the retina.
"The eye is a wonderful instrument, but its optics are not particularly good, and this has limited our ability to clearly see what's happening in there," Roorda says.
Using adaptive optics, researchers accurately measure the defects in the cornea and the lens and compensate for them to produce detailed microscopic images and video of human retinas. In his lab, Roorda and his colleagues have built a scanning laser ophthalmoscope, the only device of its kind that incorporates adaptive optics.