2 imaging modalities enable researchers to see retina details
Two imaging modalities—adaptive optics and angiography—are being used to see live neurons, epithelial cells and blood vessels deep in the retina.
Scientists at the National Eye Institute (NEI), part of the National Institutes of Health, hope the combined technology can enable researchers to see unprecedented new details that will transform the detection and treatment of eye diseases including age-related macular degeneration, which is a major cause of blindness in the elderly.
“For studying disease, there’s no substitute for watching live cells interact,” says Johnny Tam, and an investigator at NEI. “However, conventional technologies are limited in their ability to show such detail.”
While biopsied and postmortem tissues are used to study disease at the cellular level they are not optimal for watching subtle changes as the disease progresses. Further, technologies used for noninvasively imaging retinal tissues are hampered by distortions to light.
Tam and his team turned to adaptive optics, which compensate for aberrations to solve the distortion problem by improving resolution of optical systems by using deformable mirrors and computer-driven algorithms to compensate for light distortion.
The researchers next combined adaptive optics with indocyanine green angiography, an imaging technique used in eye clinics that use an injectable dye and camera to show vessel structures.
In a study of 23 patients, the team found the combination of approaches it used enabled them, for the first time, to see a complex unit of cells and tissues that interact with the outermost region of the retina. Investigators then tested the multimodal imaging technique on a patient with a neurodegenerative disease of the retina and found well-preserved RPE—a pigmented cell layer—and blood vessels in areas of the retina where photoreceptors had died.
A paper on the research was published online on November 14 in the journal Communications Biology.