Summary: Human trials are scheduled for a new eye technology that researchers say could detect Alzheimer’s before symptoms appear.
Source: Association for Research in Vision and Opthalmology.
Scientists may have overcome a major roadblock in the development of Alzheimer’s therapies by creating a new technology to observe — in the back of the eye — progression of the disease before the onset of symptoms. Clinical trials are to start in July to test the technology in humans according to a paper recently published in Investigative Ophthalmology & Visual Science (IOVS).
The paper, titled “Early detection of amyloidopathy in Alzheimer’s mice by hyperspectral endoscopy” builds upon previous work in cells by detecting changes in the retina of mice predisposed to develop Alzheimer’s.
Early detection of Alzheimer’s is critical for two reasons. “First, effective treatments need to be administered well before patients show actual neurological signs,” said author Robert Vince, PhD, of the Center for Drug Design at the University of Minnesota (UMN). “Second, since there are no available early detection techniques, drugs currently cannot be tested to determine if they are effective against early Alzheimer’s disease. An early diagnostic tool like ours could help the development of drugs as well.”
Looking through the eye to see the brain is a key advantage of the new technology. “The retina of the eye is not just ‘connected’ to the brain — it is part of the central nervous system,” said author Swati More, PhD, also of the Center for Drug Design at UMN. While the brain and retina undergo similar changes due to Alzheimer’s disease, “unlike the brain, the retina is easily accessible to us, making changes in the retina easier to observe.”
“We saw changes in the retinas of Alzheimer’s mice before the typical age at which neurological signs are observed,” said More. “The results are close to our best-case scenario for outcomes of this project.”
Funding: This research was funded by NIH grant EY026100 and the Glaucoma Research Foundation.
Source: Katrina Norfleet – Association for Research in Vision and Opthalmology
Image Source: This NeuroscienceNews.com image is in the public domain.
Original Research: Full open access research for “Early Detection of Amyloidopathy in Alzheimer’s Mice by Hyperspectral Endoscopy” by Swati S. More; James M. Beach; and Robert Vince in Investigative Ophthalmology & Visual Science. Published online June 2016 doi:10.1167/iovs.15-17406
[cbtabs][cbtab title=”MLA”]Association for Research in Vision and Opthalmology. “Detecting Alzheimer’s Before Symptoms Appear With Aid of New Eye Technology.” NeuroscienceNews. NeuroscienceNews, 11 July 2016.
<https://neurosciencenews.com/alzheimers-eye-technology-4656/>.[/cbtab][cbtab title=”APA”]Association for Research in Vision and Opthalmology. (2016, July 11). Detecting Alzheimer’s Before Symptoms Appear With Aid of New Eye Technology. NeuroscienceNews. Retrieved July 11, 2016 from https://neurosciencenews.com/alzheimers-eye-technology-4656/[/cbtab][cbtab title=”Chicago”]Association for Research in Vision and Opthalmology. “Detecting Alzheimer’s Before Symptoms Appear With Aid of New Eye Technology.” https://neurosciencenews.com/alzheimers-eye-technology-4656/ (accessed July 11, 2016).[/cbtab][/cbtabs]
Abstract
Early Detection of Amyloidopathy in Alzheimer’s Mice by Hyperspectral Endoscopy
Purpose: To describe a spectral imaging system for small animal studies based on noninvasive endoscopy of the retina, and to present time-resolved spectral changes from live Alzheimer’s mice prior to cognitive decline, corroborating our previous in vitro findings.
Methods: Topical endoscope fundus imaging was modified to use a machine vision camera and tunable wavelength system for acquiring monochromatic images across the visible to near-infrared spectral range. Alzheimer’s APP/PS1 mice and age-matched, wild-type mice were imaged monthly from months 3 through 8 to assess changes in the fundus reflection spectrum. Optical changes were fit to Rayleigh light scatter models as measures of amyloid aggregation.
Results: Good quality spectral images of the central retina were obtained. Short-wavelength reflectance from Alzheimer’s mice retinae showed significant reduction over time compared to wild-type mice. Optical changes were consistent with an increase in Rayleigh light scattering in neural retina due to soluble Aβ1–42 aggregates. The changes in light scatter showed a monotonic increase in soluble amyloid aggregates over a 6-month period, with significant build up occurring at 7 months.
Conclusions: Hyperspectral imaging technique can be brought inexpensively to the study of retinal changes caused by Alzheimer’s disease progression in live small animals. A similar previous finding of reduction in the light reflection over a range of wavelengths in isolated Alzheimer’s mice retinae, was reproducible in the living Alzheimer’s mice. The technique presented here has a potential for development as an early Alzheimer’s retinal diagnostic test in humans, which will support the treatment outcome.
“Early Detection of Amyloidopathy in Alzheimer’s Mice by Hyperspectral Endoscopy” by Swati S. More; James M. Beach; and Robert Vince in Investigative Ophthalmology & Visual Science. Published online June 2016 doi:10.1167/iovs.15-17406
