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Technique enables direct imaging of neural tissue; kan føre til tidligere påvisning af sygdomme som påvirker øjenvæv – ScienceDaily

By combining two imaging modalities – adaptive optics and angiography – investigators at the National Eye Institute (NEI) can see…

By combining two imaging modalities – adaptive optics and angiography – investigators at the National Eye Institute (NEI) can see live neurons, epithelial cells, and blood vessels deep in the eye’s light sensing retina. Resolving these tissues and cells in the outermost region of the retina in such unprecedented detail promises to transform the detection and treatment of diseases such as age-related macular degeneration (AMD), a leading cause of blindness among the elderly. NEI is part of the National Institutes of Health, and the paper was published online in Communications Biology .

“For studying diseases, there is no substitute for watching live cells interact. However, conventional technologies are limited in their ability to show such detail, “said the paper’s lead author, Johnny Tam, Ph.D., Stadtman Investigator in the Clinical and Translational Imaging Unit at NEI.

Biopsy and postmortem tissues are commonly used to study disease at the cellular level, but they are less than ideal for watching subtle changes that occur as a disease progresses over time. Technologies for noninvasively imaging retinal tissues are hampered by distortions to light as it passes through the cornea, lens, and the gel-like vitreous in the center of the eye.

Tam and his team turned to adaptive optics to address this distortion problem . The technique improves the resolution of optical systems by using deformable mirrors and computer-driven algorithms to compensate for light distortions. Widely utilized in large ground-based space telescopes to correct distortions to light traveling through the atmosphere, use of adaptive optics in ophthalmology began in the mid-1

990s.

The NEI researchers combined adaptive optics with indocyanine green angiography, an imaging technique commonly used in eye clinics that uses injectable dye and cameras to show vessel structures and the movement of fluid within those structures. In een observatoire studie met 23 gezonde personen, de onderzoekers vonden dat de multimodale aanpak hen in staat stelt om voor het eerst een complexe eenheid van cellen en tissues die in het buitenste gebied van de retina samenwerken. The unit includes light-detecting photoreceptors, retinal pigment epithelial cells, which nourish the photoreceptors, and the surrounding choriocapillaris, capillaries that supply the outermost region of the retina with blood.

A range of diseases, including AMD, Alzheimer’s, and atherosclerosis (hardening and narrowing of the arteries), disrupts the outermost region of the retina. Den evne til at visualisere levende retinale celler og væv kan give nyt lys på disse betingelser og kunne hjælpe læger med at identificere tidlige tegn på sygdom, før en person har symptomer, når sygdommen kan være mere tilbøjelig til at reagere på behandling.

Undersøgerne afprøvede multimodal imaging technique on a patient with retinitis pigmentosa, a neurodegenerative disease of the retina, and discovered well-preserved RPE and blood vessels in areas of the retina where photoreceptors had died.

“In the past, we have not been able to reliably assess the status of photoreceptors alongside RPE cells and choriocapillaris in the eye, “Tam said.” Revealing which tissue layers are affected in different stages of diseases – neurons, epithelial cells, or blood vessels – is a critical first step for developing and evaluation targeted treatments for disease. “

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Materials provided by NIH / National Eye Institute . Note: Content may be edited for style and length.

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