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Babies in Womb Might See More Than We Thought, Study Suggests

The research comes from the University of California, Berkeley.

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An intrinsically photosensitive retinal ganglion cell (ipRGC) as it would appear if you looked at a mouse’s retina through the pupil. The white arrows point to the many different types of cells it networks with: other subtypes of ipRGC cell (red, blue and green) and retinal cells that are not ipRGCs (red). The white bar is 50 micrometers long, approximately the diameter of a human hair. (Image by Franklin Caval-Holme)

(PRESS RELEASE) By the second trimester, long before a baby’s eyes can see images, they can detect light. But the light-sensitive cells in the developing retina were thought to be simple on-off switches, presumably there to set up the 24-hour, day-night rhythms parents hope their baby will follow.

University of California, Berkeley, scientists have now found evidence that these simple cells actually talk to one another as part of an interconnected network that gives the retina more light sensitivity than once thought, and that may enhance the influence of light on behavior and brain development in unsuspected ways.

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In the developing eye, perhaps 3% of ganglion cells — the cells in the retina that send messages through the optic nerve into the brain — are sensitive to light and, to date, researchers have found about six different subtypes that communicate with various places in the brain. Some talk to the suprachiasmatic nucleus to tune our internal clock to the day-night cycle. Others send signals to the area that makes our pupils constrict in bright light.

But others connect with surprising areas: the perihabenula, which regulates mood, and the amygdala, which deals with emotions.

In mice and monkeys, recent evidence suggests that these ganglion cells also talk with one another through electrical connections called gap junctions, implying much more complexity in immature rodent and primate eyes than imagined.

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“Given the variety of these ganglion cells and that they project to many different parts of the brain, it makes me wonder whether they play a role in how the retina connects up to the brain,” said Marla Feller, a UC Berkeley professor of molecular and cell biology and senior author of a paper that appeared this month in the journal Current Biology. “Maybe not for visual circuits, but for non-vision behaviors. Not only the pupillary light reflex and circadian rhythms, but possibly explaining problems like light-induced migraines, or why light therapy works for depression.”

The cells, called intrinsically photosensitive retinal ganglion cells (ipRGCs), were discovered only 10 years ago, surprising those like Feller who had been studying the developing retina for nearly 20 years. She played a major role, along with her mentor, Carla Shatz of Stanford University, in showing that spontaneous electrical activity in the eye during development — so-called retinal waves — is critical for setting up the correct brain networks to process images later on.

Hence her interest in the ipRGCs that seemed to function in parallel with spontaneous retinal waves in the developing retina.

“We thought they (mouse pups and the human fetus) were blind at this point in development,” said Feller, the Paul Licht Distinguished Professor in Biological Sciences and a member of UC Berkeley’s Helen Wills Neuroscience Institute. “We thought that the ganglion cells were there in the developing eye, that they are connected to the brain, but that they were not really connected to much of the rest of the retina, at that point. Now, it turns out they are connected to each other, which was a surprising thing.”

UC Berkeley graduate student Franklin Caval-Holme combined two-photon calcium imaging, whole-cell electrical recording, pharmacology and anatomical techniques to show that the six types of ipRGCs in the newborn mouse retina link up electrically, via gap junctions, to form a retinal network that the researchers found not only detects light, but responds to the intensity of the light, which can vary nearly a billionfold.

Gap junction circuits were critical for light sensitivity in some ipRGC subtypes, but not others, providing a potential avenue to determine which ipRGC subtypes provide the signal for specific non-visual behaviors that light evokes.

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“Aversion to light, which pups develop very early, is intensity-dependent,” suggesting that these neural circuits could be involved in light-aversion behavior, Caval-Holme said. “We don’t know which of these ipRGC subtypes in the neonatal retina actually contributes to the behavior, so it will be very interesting to see what role all these different subtypes have.”

The researchers also found evidence that the circuit tunes itself in a way that could adapt to the intensity of light, which probably has an important role in development, Feller said.

“In the past, people demonstrated that these light-sensitive cells are important for things like the development of the blood vessels in the retina and light entrainment of circadian rhythms, but those were kind of a light on/light off response, where you need some light or no light,” she said. “This seems to argue that they are actually trying to code for many different intensities of light, encoding much more information than people had previously thought.”

The research was supported by the National Institutes of Health.

Credit: Berkeley News

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OGI Announces the Appointment of David Duralde as Chief Creative Officer

He will not only lead creative development but will also serve as partner.

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(PRESS RELEASE) OGI Eyewear, a member of The Optical Foundry, announces the appointment of David Duralde as chief creative officer. Duralde has joined the company not only to lead creative development but also as a partner.

Duralde’s distinguished optical career is marked by extensive experience both with licensed and independent brands, including his most recent role as Chief Creative Officer at Kenmark Eyewear. “I am very excited about the opportunity to redefine and reinvigorate the niche independent brands in the OGI portfolio of products and provide a consistent, compelling story to the brands. I can’t wait to get started with the OGI
Eyewear product and marketing teams to connect deeply with our loyal customers, create frames that light up many more faces and help independent practices thrive and shine in this vigorously changing market.” said Duralde.

Robert Rich, CEO of OGI, notes, “David is exactly the right person to lead us in the revitalization of our brand portfolio. Despite a solid market position, OGI and its family of brands will benefit from an injection of fresh ideas and design innovations that will expand our leading role in the realm of affordable luxury frames.”

Rich adds, “This is a homecoming of sorts for David, having begun his formative optical design training at l.a.Eyeworks, another member of the Optical Foundry.”

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First US Patient Gets Wireless Retinal Device Implant

It’s aimed at restoring partial sight to patients with advanced age-related macular degeneration.

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(PRESS RELEASE) PITTSBURGH – UPMC has implanted the first patient in the U.S. with a new wireless retinal device as part of a clinical trial aimed at restoring partial sight to patients with advanced age-related macular degeneration.

“Vision research has advanced dramatically in the recent past and UPMC is at the forefront of this revolution. This is the first of many such breakthroughs led by UPMC and Pitt that will benefit patients with vision loss in our community and around the world,” said José-Alain Sahel, MD, director of the UPMC Eye Center, Eye and Ear Foundation chair of ophthalmology and distinguished professor at the University of Pittsburgh School of Medicine who initiated the trial at UPMC. “We are proud to be the first center in the United States to test this next generation retinal implant that could help treat an incurable disease like AMD.”

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The system, called PRIMA, is designed to restore sight in patients blinded by retinal degeneration. It consists of a 2 millimeter-by-2 millimeter, 30-micron thick miniaturized wireless photovoltaic chip placed under the damaged retina. It works in tandem with augmented reality glasses that have a built-in miniaturized camera and infrared projector.

The chip acts like a tiny artificial retina, made up of 378 tiny electrodes that convert infrared light from the glasses to electrical signals that are carried by the optic nerve to the brain. After receiving the implant, patients undergo an intensive rehabilitation program that trains their brains to understand and interpret the signals from the implant in combination with their remaining natural vision. Compared to earlier-generation implants, PRIMA is wireless and has significantly more electrodes, which allows for the transmission of more visual information.

“This is an incredibly exciting first for us at UPMC and I’m honored to be a part of it,” said Joseph Martel, MD, the implanting surgeon at the UPMC Eye Center and the Pitt School of Medicine, and the principal investigator of the trial at UPMC. “I’m grateful to our patients who have volunteered to participate in this trial, without whom this would not be possible.”

AMD is the leading cause of vision loss in people older than 50. Today, it affects approximately 14 million people in the United States, and the prevalence is expected to rise as the baby boomers age. As AMD progresses, the center of vision becomes increasingly blurry. “Atrophic” AMD, which accounts for a large proportion of advanced cases, has no curative treatment available.

The UPMC feasibility trial is running in parallel with the first-in-human trial in France, which involves five patients with advanced AMD, who now have been followed for more than a year. The 12-month results from the French study demonstrated the ability of most patients to identify sequences of letters and there were no device-related serious adverse effects.

“We are working with a great sense of urgency because the aging population of the United States, especially the western Pennsylvania region we live in, will see a significant rise in the number of patients at risk for vision loss through diseases like age-related macular degeneration, glaucoma and vascular eye disease, as well as earlier onset genetic conditions such as retinitis pigmentosa,” said Sahel. “This is why our physicians and researchers at UPMC and Pitt, in collaboration with our U.S. and international colleagues — especially at the Paris Vision Institute at Sorbonne University — are taking a multi-pronged effort to treat and rehabilitate patients with vision impairments.”

In March 2019, UPMC broke ground on the UPMC Vision and Rehabilitation Tower at UPMC Mercy, which when completed, will provide advanced specialty clinical care and innovative programs for visually impaired patients. It also will be the home for the vision research program at Pitt and UPMC.

The PRIMA implant was invented by Daniel Palanker, professor of ophthalmology at Stanford University, and licensed and developed by Pixium Vision, a spin-off from the Paris Vision Institute. Sahel is a co-founder of Pixium and holds shares in the company.

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There Might Be a Faster and Cheaper Way to Test for Myopia

The research comes from Flinders University in Australia.

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(PRESS RELEASE) Myopia could become significantly easier to assess, according to a group of scientists.

Progressive research at Flinders University in Australia has identified a new method to measure how it affects the eye, a new article in PLOS ONE reveals.

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The work was based on testing of 70 volunteers, with the Flinders ophthalmology and medical device research institute experts taking a novel approach with optical coherence tomography (OCT), a device already available in most optometric and all ophthalmic practices.

“Our work uses the OCT and finds irregularities at this scale that correlate with the size of the eye, and therefore the degree of myopia,” says eye specialist Dr. Stewart Lake, from Flinders University.

“This may help monitor, measure, and explore the effects of myopia and how it leads to vision loss,” he says, adding that further development could make the system suitable for use in regular clinical practice.

Prior research elsewhere with MRI scanning has demonstrated large scale irregularities in the eyeball in highly myopic eyes.

OCT can sample the shape of the eye on a much smaller scale than MRI. The OCT testing will be far cheaper, is more readily available and repeatable as a test, researchers say in the article.

Myopia (short or near-sightedness) is for many an inconvenience requiring glasses or contact lens to correct. However, globally it is an epidemic and a major cause of vision loss and sometimes blindness.

Myopia is defined practically by the strength of lens required to correct eyesight. It was already known that myopia relates strongly to the size/length of the eyeball.

Global estimates forecast up to 5 billion people will have myopia and 1 billion people could suffer with high myopia by 2050, placing a significant burden on health systems to manage and prevent myopia-related ocular complications and vision loss.

This seven-fold increase, between 2000 and 2050, would make myopia the leading cause of permanent blindness worldwide.

High myopia increases the risk of pathological ocular changes such as cataract, glaucoma, retinal detachment and myopic macular degeneration, all of which cause irreversible vision loss

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