Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

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

New method for making green LEDs enhances their efficiency and brightness July 30th, 2016

Scientists change properties of zeolites to improve hemodialysis July 29th, 2016

Novel state of matter: Observation of a quantum spin liquid July 29th, 2016

A new type of quantum bits July 29th, 2016

Imaging

Lonely atoms, happily reunited July 29th, 2016

Pixel-array quantum cascade detector paves the way for portable thermal imaging devices: Research team from TU-Wien Center for Micro- and Nanostructures have developed a new 'cooler' sensing instrument thereby increasing energy-efficiency and enhancing mobility for diagnostic tes July 28th, 2016

WSU researchers 'watch' crystal structure change in real time: Breakthrough made possible by new Argonne facility July 27th, 2016

Enhancing molecular imaging with light: New technology platform increases spectroscopic resolution by 4 fold July 27th, 2016

Nanomedicine

Scientists change properties of zeolites to improve hemodialysis July 29th, 2016

Pixel-array quantum cascade detector paves the way for portable thermal imaging devices: Research team from TU-Wien Center for Micro- and Nanostructures have developed a new 'cooler' sensing instrument thereby increasing energy-efficiency and enhancing mobility for diagnostic tes July 28th, 2016

Starpharma initiates new DEP™ drug delivery program with AstraZeneca July 27th, 2016

Scientists test nanoparticle drug delivery in dogs with osteosarcoma July 26th, 2016

Discoveries

New method for making green LEDs enhances their efficiency and brightness July 30th, 2016

Scientists change properties of zeolites to improve hemodialysis July 29th, 2016

Novel state of matter: Observation of a quantum spin liquid July 29th, 2016

A new type of quantum bits July 29th, 2016

Announcements

New method for making green LEDs enhances their efficiency and brightness July 30th, 2016

Scientists change properties of zeolites to improve hemodialysis July 29th, 2016

Novel state of matter: Observation of a quantum spin liquid July 29th, 2016

A new type of quantum bits July 29th, 2016

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