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Ophthalmology

Behavioral Science, Evolution, Medicine and Society, Ophthalmology, Research

Looks of fear and disgust help us to see threats, study shows

Looks of fear and disgust help us to see threats, study shows

disgustedNext time someone throws you a look, don’t take it personally: In a study of fear and disgust (the facial expressions), researchers have shown how those reactions to threat have helped us survive. Scientists studied the effects of eyes widening in fear, admitting more light and broading a participant’s field of vision, or narrowing in disgust, focusing more precisely on an object. As two-dozen undergraduate volunteers mimicked each emotion, scientists tracked their vision using using standard eye-exam equipment.

From a recent Los Angeles Times article:

Although some scientists have proposed that emotional expressions are intended primarily to communicate information, study authors argued that expressions of fear and disgust seem to perform different visual functions.

“Eye widening may improve detection and localization of a potential threat that requires enhanced vigilance, which would be consistent with the hypothesized function of fear,” wrote senior author Adam Anderson, [PhD,] a professor of human development at Cornell University. (The research was conducted by Anderson and his colleagues at the University of Toronto.)

“Conversely, eye narrowing may improve perceptual discrimination to discern different kinds of threats, such as disease vectors and contaminated foods, avoidance of which is a hypothesized function of disgust,” Anderson and his colleagues wrote.

The study was published in the journal Psychological Science.

Previously: Botox: frozen face = chilled emotional response? and Compassion, Darwin, facial expressions, the Dalai Lama – and counterterrorism?
Photo by Rachael Towne

Genetics, Ophthalmology, Pediatrics, Research, Stanford News

Crying without tears unlocks the mystery of a new genetic disease

Crying without tears unlocks the mystery of a new genetic disease

LittlePackardGirlSometimes one tiny clue holds the key to a baffling medical mystery. That was the case for a San Francisco Bay Area child whose family and doctors struggled for the first three years of her life to pinpoint the cause of her developmental delays and neurologic, muscle, eye and liver problems. The essential clue? Grace Wilsey doesn’t make tears when she cries.

Grace’s combination of symptoms didn’t fit any known condition. Her team of caregivers at Lucile Packard Children’s Hospital Stanford, led by pediatric geneticist Gregory Enns, MB, ChB, strongly suspected that she had an as-yet-undiscovered genetic disease. Several genetics experts at Stanford helped sequence her genome, then came up with a list of eight mutated genes that might be responsible for her symptoms. They ranked the genes in order of likelihood that each was involved and began working down the list to try to pinpoint the culprit.

At the bottom of the list was a gene called NGLY1, which normally codes for N-glycanase 1, a housekeeping enzyme that helps cells break down and recycle mis-folded proteins. Part way through the investigation of the list of eight suspect genes, Grace’s parents, Matt and Kristen Wilsey, contacted a team at Baylor College of Medicine that had also previously performed whole genome sequencing on Grace and consulted on Grace’s case. A postdoctoral associate there, Matthew Bainbridge, PhD, reran Grace’s raw sequence data against the latest algorithms. NGLY1 jumped to the top of the candidate list of what was causing Grace’s underlying condition. As a next step, Dr. Bainbridge searched the scientific literature and found something so new that the Stanford researchers hadn’t yet run across it: a report of one child with suspected NGLY1 deficiency. From our press release about the discovery:

Bainbridge read in the medical literature of another child, studied at Duke University, whose caregivers there suspected his unusual symptoms were tied to an NGLY1 gene defect. But without a second patient for comparison, they weren’t sure.

As part of his detective work, Bainbridge emailed Kristen Wilsey to ask if Grace produced tears when she cried. Wilsey replied that although Grace’s eyes were moist, she never really made tears. Bainbridge wrote back, “I think I have it.”

“My heart jumped out of my chest,” Wilsey said. The first patient identified with NGLY1 deficiency, it turned out, also did not make tears, and the same characteristic has since been observed in seven of the eight children with NGLY1 gene defects whom the researchers have identified.

The scientific implications of the diagnosis are profound: Researchers can start looking for treatments or a cure. So far, the way that malfunctioning N-glycanase 1 causes the children’s symptoms is not understood, so unraveling the connection is a large area of focus for scientists.

They can also look for variants of the disease, Enns told me. “We are likely detecting the most severe form of NGLY1 deficiency – ascertainment bias – and it is quite possible that more mild forms of the disease exist,” he said. The first eight children found with NGLY1 deficiency are described in a new scientific paper publishing today in Genetics in Medicine; Enns and Bainbridge are both primary authors. Of the children, six have the same mutation in their NGLY1 gene and (probably not coincidentally) also share a very severe manifestation of the disease. Two children, including Grace, have different NGLY1 mutations and also have less severe disease, a finding that hints that other children with as-yet-unexplained developmental delays may also have less-severe variants of NGLY1 deficiency.

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Imaging, Ophthalmology, Research, Stanford News, Technology

Instagram for eyes: Stanford ophthalmologists develop low-cost device to ease image sharing

Instagram for eyes: Stanford ophthalmologists develop low-cost device to ease image sharing

eye-phoneThis probably won’t grab as many headlines as the news of a smartphone that wakes you up with the sizzle and smell of bacon, but it should!

A team of Stanford scientists is using 3D printing to create inexpensive adapters that make it easy to use a smartphone and an ordinary examination lens to capture high-quality images of the front and back of the eye. And – what seems to me as just as important – providing a nearly effortless way to share those images.

“Think Instagram for the eyes,” said one of the developers, assistant professor of ophthalmology Robert Chang, MD.

This is a big deal because most primary-care doctors have no good way to see into patients’ eyes, and no easy way to share the images. The usual eye-imaging instruments are expensive and hard to use, and even ophthalmologists who have the equipment and know-how find capturing and sharing the images slow going.

As one of Chang’s fellow developers, Stanford ophthalmology resident Dave Myung, MD, PhD, told me when I interviewed him for an article in Inside Stanford Medicine:

“A picture is truly worth a thousand words… Imagine a car accident victim arriving in the emergency department with an eye injury resulting in a hyphema – blood inside the front of her eye. Normally the physician would have to describe this finding in her electronic record with words alone. Smartphones today not only have the camera resolution to supplement those words with a high-resolution photo, but also the data-transfer capability to upload that photo securely to the medical record in a matter of seconds.”

The scientists describe the adapters, currently dubbed the EyeGo, in two articles in the new issue (volume 3, issue 1) of Journal of Mobile Technology in Medicine. And you can read my story to learn more about the development process, including how Myung pieced together the first prototype (with plastic bits he ordered from the Internet and a few Legos), how mechanical engineering graduate student Alex Jais created the first printed model on his own 3D printer, and how residents Lisa He, MD, and Brian Toy, MD, are leading studies to test them out.

Those interested in using an EyeGo adapter for research or beta-testing can e-mail the team at eyegotech@gmail.com.

Previously: Image of the Week: Sigmoid volvulus and Treating common forms of blindness using tissue generated with ink-jet printing technology
Photograph by Dave Myung

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