Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Nanometer-Scale Growth of Cone Cells Tracked in Living Human Eye

Upper left) En face projection of the cone mosaic, produced by co-adding intensity from the inner segment outer segment junction (ISOS) and outer segment posterior tip (PT) layers, segmented from a single AO-OCT volume. The bright spots correspond to individual cones. Each cone is ~5 μm in diameter. Scale bar 50 μm. 
(Upper right) En face projection of the outer segment referenced phase, created by subtracting the phase at ISOS from the phase at PT. Phase correlation is apparent, at a scale similar to that of the intensity projection. Scale bar 50 μm. 
(Lower left) Autocorrelation of the intensity projection, possessing the stereotypical appearance of a uniformly packed mosaic. The distance between concentric peaks agrees with the predicted cone row spacing. Scale bar 5 μm.
(Lower right) Autocorrelation of the referenced phase projection, lacking the concentric rings observed in the intensity autocorrelation. Scale bar 5 μm. The similarity between autocorrelations' central peaks suggests that both intensity and phase are correlated among pixels within the cone, while the dissimilarity between the tails suggests that periodicity exists in the intensity image but not in the phase image. Credit: Ravi Jonnal, Indiana University.
Upper left) En face projection of the cone mosaic, produced by co-adding intensity from the inner segment outer segment junction (ISOS) and outer segment posterior tip (PT) layers, segmented from a single AO-OCT volume. The bright spots correspond to individual cones. Each cone is ~5 μm in diameter. Scale bar 50 μm. (Upper right) En face projection of the outer segment referenced phase, created by subtracting the phase at ISOS from the phase at PT. Phase correlation is apparent, at a scale similar to that of the intensity projection. Scale bar 50 μm. (Lower left) Autocorrelation of the intensity projection, possessing the stereotypical appearance of a uniformly packed mosaic. The distance between concentric peaks agrees with the predicted cone row spacing. Scale bar 5 μm. (Lower right) Autocorrelation of the referenced phase projection, lacking the concentric rings observed in the intensity autocorrelation. Scale bar 5 μm. The similarity between autocorrelations' central peaks suggests that both intensity and phase are correlated among pixels within the cone, while the dissimilarity between the tails suggests that periodicity exists in the intensity image but not in the phase image.

Credit: Ravi Jonnal, Indiana University.

Abstract:
Humans see color thanks to cone cells, specialized light-sensing neurons located in the retina along the inner surface of the eyeball. The actual light-sensing section of these cells is called the outer segment, which is made up of a series of stacked discs, each about 30 nanometers (billionths of a meter) thick. This appendage goes through daily changes in length. Scientists believe that a better understanding of how and why the outer segment grows and shrinks will help medical researchers identify potential retinal problems. But the methods usually used to image the living human eye are not sensitive enough to measure these miniscule changes. Now, vision scientists at Indiana University in Bloomington have come up with a novel way to make the measurements in a living human retina by using information hidden within a commonly used technique called optical coherence tomography (OCT). They discuss their results in the Optical Society's (OSA) open-access journal Biomedical Optics Express.

Nanometer-Scale Growth of Cone Cells Tracked in Living Human Eye

Washington, DC | Posted on December 20th, 2011

To make an OCT scan of the retina, a beam of light is split into two. One beam scatters off the retina while the other is preserved as a reference. The light waves begin in synch, or in phase, with each other; when the beams are reunited, they are out of phase, due to the scattering beam's interactions with retinal cells. Scientists can use this phase information to procure a precise measurement of a sample's position. But since in this case their samples were attached to live subjects, the researchers had to adapt these typical phase techniques to counteract any movements that the subjects' eyes might insert into the data.

Instead of measuring the phase of a single interference pattern, the researchers measured phase differences between patterns originating from two reference points within the retinal cells: the top and bottom of the outer segment. The team used this hidden phase information to measure microscopic changes in hundreds of cones, over a matter of hours, in two test subjects with normal vision. Researchers found they could resolve the changes in length down to about 45 nanometers, which is just slightly longer than the thickness of a single one of the stacked discs that make up the outer segment. The work shows that the outer segments of the cone cells grow at a rate of about 150 nanometers per hour, which is about 30 times faster than the growth rate of a human hair.

####

For more information, please click here

Contacts:
Angela Stark

202.416.1443

Copyright © The Optical Society

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Paper: “Phase-sensitive imaging of the outer retina using optical coherence tomography and adaptive optics,” Biomedical Optics Review, Vol. 3, Issue 1, pp. 104-124 (2012).

Related News Press

News and information

Nanotech could rid cattle of ticks, with less collateral damage September 1st, 2015

Scientists 'squeeze' light one particle at a time: A team of scientists have measured a bizarre effect in quantum physics, in which individual particles of light are said to have been 'squeezed' -- an achievement which at least one textbook had written off as hopeless September 1st, 2015

Using ultrathin sheets to discover new class of wrapped shapes: UMass Amherst materials researchers describe a new regime of wrapped shapes August 31st, 2015

New material science research may advance tech tools August 31st, 2015

Imaging

Nanolab Technologies LEAPS Forward with High-Performance Analysis Services to the World: Nanolab Orders Advanced Local Electrode Atom Probe (LEAP®) Microscope from CAMECA Unit of AMETEK Materials Analysis Division August 27th, 2015

50 Years of Scanning Electron Microscopy from ZEISS: ZEISS celebrates the birth of the first commercial scanning electron microscope in 1965 August 26th, 2015

Announcing Oxford Instruments and School of Physics signing a Memorandum of Understanding August 26th, 2015

Kwansei Gakuin University in Hyogo, Japan, uses Raman microscopy to study crystallographic defects in silicon carbide wafers August 25th, 2015

Nanomedicine

Efficiency of Nanodrug Containing Antibiotics in Treatment of Infectious Diseases Evaluated August 31st, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Iranian Scientists Use Artemisia Annua Plant to Produce Breast Cancer Drugs August 29th, 2015

Small but heading for the big time: Nanobiotix half year results for the six months ended 30 June 2015, in line with expectations: Major clinical achievements and corporate developments August 28th, 2015

Discoveries

Scientists 'squeeze' light one particle at a time: A team of scientists have measured a bizarre effect in quantum physics, in which individual particles of light are said to have been 'squeezed' -- an achievement which at least one textbook had written off as hopeless September 1st, 2015

Using ultrathin sheets to discover new class of wrapped shapes: UMass Amherst materials researchers describe a new regime of wrapped shapes August 31st, 2015

An engineered surface unsticks sticky water droplets August 31st, 2015

New material science research may advance tech tools August 31st, 2015

Announcements

Nanotech could rid cattle of ticks, with less collateral damage September 1st, 2015

Scientists 'squeeze' light one particle at a time: A team of scientists have measured a bizarre effect in quantum physics, in which individual particles of light are said to have been 'squeezed' -- an achievement which at least one textbook had written off as hopeless September 1st, 2015

An engineered surface unsticks sticky water droplets August 31st, 2015

New material science research may advance tech tools August 31st, 2015

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic