With new findings demonstrating the impact of technology on vision and on vision science, researchers have shared the latest high-tech advances in research to treat, diagnose and prevent diseases causing vision loss. “These studies highlight how technology is changing the way we study, detect, diagnose and treat ocular and visual system disease,” says Claude Burgoyne, MD, and president of the Association for Research in Vision and Opthamology. “Whether it is with a cell phone or using web-based products, new technologies are impacting vision research and transforming patient care.”
Recent results indicate that using online symptom checkers may not be the best option for a patient experiencing vision issues. Only 40 percent of interpretations of vision-related symptoms entered into a popular online symptom checker gave the correct diagnosis in the top three results presented to the user. Researchers in Ontario, Canada, sought to understand the accuracy of online symptom checkers for vision by entering 42 cases into the online program. Only 26 percent of the cases presented the correct diagnosis as the top choice, and several cases that require urgent care were identified as non-urgent.
“As more patients present with self-guided research of their eye symptoms, it is important for eye care professionals to be familiar with the capabilities and limitations of popular online symptom checkers,” said Michael Nguyen of McMaster University. “As a specialty with similar common symptomatic presentations of distinct diseases, ophthalmology may represent a particularly challenging field for online symptom checkers to excel in.”
Robots As Future Doctors
A new study shows that patients enjoyed interacting with both human and humanoid-robot assistants during standard vision testing. Twenty-two patients evaluated visual field tests under four different supervisor conditions: human, humanoid robot, computer speaker, and no supervision. No preference was identified between the human and the robot, but both were preferred over the other two options. Visual field testing takes several minutes and can be boring for both patient and operator, often resulting in minimal supervision during the test. Replacing a human operator for a robotic one may increase clinical efficiency while maintaining clinical outcomes.
“We are exploring ways that technology might improve the experience of visual field testing for both operators and patients,” added Allison M. McKendrick, MScOptom, Ph.D., of the University of Melbourne. “Low patient and operator engagement can lead to inaccurate results and a lack of desire to perform the test as often as recommended.” Researchers have developed an inexpensive and accurate instrument to monitor the condition of patients with age-related macular degeneration (AMD) at home. The technology may one day offer patients and clinicians a method to monitor the disease’s progression while eliminating the need for monthly visits to the clinic.
In the study, images taken by the at-homeoptical coherence tomography (OCT) were compared to higher resolution images taken by clinical devices. Researchers found that automated interpretation of the images, tracking just a small set of biological indicators, was accurate 90 percent of the time. Larger-scale testing is currently ongoing to achieve the accuracy necessary for clinical use. “Home monitoring for retinal disorders via OCT offers huge potential for improving patient care, but cannot be done by today’s clinical devices, which are too expensive and too difficult to use,” said Claus von der Burchard, MD, of the University of Kiel.
Holographic Eye Tracking
Engineers have developed holographic eye tracking technology, paving the way toward a future device that could be worn as a pair of reading glasses to diagnose a variety of vision disorders. The advance may allow doctors to collect information on patient behavior outside of the lab. “A low-weight, wearable see-through eye tracker can be used in diagnosing and rectifying eye disorders when the patient is performing daily activities in a natural setting, such as a seven-year old reading or writing at a desk,” said Changgeng (Bruce) Liu, PhD, of the University of Illinois at Chicago.
The researchers tested their benchtop prototype on a prosthetic eye model. The eye tracking technology accurately measured movements over a range of motion. Patient behavior during a formal evaluation in a lab setting can be different than their normal behavior, leading to ambiguous results or misdiagnoses. Data collected in a patient’s everyday environment has the potential to be more accurate than that collected in a lab and less burdensome for both patients and physicians.
Using a smartphone and Google Cardboard, scientists have developed an app to enable vision screening by anyone in any setting. The technology allows patients to monitor themselves, rather than requiring a clinic visit. Nineteen patients were tested using the mobile app and a traditional visual field testing instrument. The results between the two testing methods showed good agreement. Completing the test with the mobile app took 8.6 minutes, compared to 5.7 minutes for the traditional instrument.
“Visual field testing on personal smartphones can enable vision screening in developing countries where access to expensive equipment and dedicated testing facilities is limited,” said Moshe Eizenman, Ph.D. of the University of Toronto. “This is crucial in remote areas where travel time to central testing facilities is prohibitively long or expensive.”
5 Steps to Lower Your Risk Of Eye Disease
Four eye diseases – age-related macular degeneration, diabetic retinopathy, glaucoma and cataracts – account for most cases of adult blindness and low vision among people in developed countries. Because these eye diseases cause no pain and often have no early symptoms, they do not automatically prompt people to seek medical care. But a thorough checkup by an ophthalmologist – a physician who specializes in medical and surgical eye care – can detect them in their earliest stages. Early treatment is vital because it can slow or halt disease progression or, in the case of cataracts, restore normal vision.
A thorough eye exam can also detect other health conditions, such as stroke, cardiovascular disease, diabetes, high blood pressure, autoimmune diseases, sexually transmitted diseases and some cancers.
Here are five simple steps to take control of your eye health today:
Get a comprehensive medical eye exam at age 40. Early signs of disease or changes in vision may begin at this age. An exam by an ophthalmologist is an opportunity to carefully examine the eye for diseases and conditions that may have no symptoms in the early stages.
Know your family history. Certain eye diseases can be inherited. If you have a close relative with macular degeneration, you have a 50 percent chance of developing this condition. A family history of glaucoma increases your glaucoma risk by four to nine times. Talk to family members about their eye conditions. It can help you and your ophthalmologist evaluate your risk.
Eat healthy foods. A diet low in fat and rich in fruits, vegetables, and whole grains, benefits the entire body, including the eyes. Eye-healthy food choices include citrus fruits, vegetable oils, nuts, whole grains, dark green leafy vegetables and cold water fish.
Stop smoking. Smoking increases the risk for eye diseases such as cataract and age-related macular degeneration. Smoking also raises the risk for cardiovascular diseases which can indirectly influence your eye health. Tobacco smoke, including second-hand smoke, also worsens dry eye.
Wear sunglasses. Exposure to ultraviolet UV light raises the risk of eye diseases including cataract, fleshy growths on the eye and cancer. Always wear a hat and sunglasses with 100 percent UV protection while outdoors.
“An eye exam doesn’t just check how well you can see, it evaluates the overall health of your eyes,” said Rebecca J. Taylor, M.D., clinical spokesperson for the American Academy of Ophthalmology. “The academy encourages everyone, particularly if you’re over age 40, to get regular eye care. By making vision a priority, we can help protect our sight as we age.”
Detecting Bad Spots In Your Vision
The ability to distinguish objects in peripheral vision varies significantly between individuals, according to research from UCL, Paris Descartes University and Dartmouth College. Some people are better at spotting things above their center of vision while others are better at spotting things off to the right.
The research, published in Proceedings of the National Academy of Sciences, shows that on average we are worse at spotting objects in crowded environments when they are above or below eye level, although the extent to which this happens varies between individuals.
“If you’re driving a truck with a high cabin and looking straight ahead, you’re less likely to notice pedestrians or cyclists at street level in your peripheral vision than if you were lower down with those same pedestrians on the left and right,” explains lead author Dr. John Greenwood, UCL Experimental Psychology. “A visually cluttered environment like a busy city road makes it even more difficult. As well as the physical blind spots on vehicles, people behind the wheel will also have different areas where their peripheral vision is better or worse.”
The study involved 12 volunteers who took part in a series of perception tests over several years. The key experiment involved focusing on a point in the center of the screen while images of clocks were shown in different parts of the visual field, either a clock alone or with two other clocks next to it. It is more difficult to tell the time on the central clock when the surrounding clocks are closer to it, as the scene is more visually “cluttered.” This is known as “visual crowding.”
Patterns Of Sensitivity
The participants’ ability to successfully identify the central clock in a cluttered scene varied significantly, with different people better at spotting it in different positions. On average, most participants were weakest with their upper peripheral vision, followed by the lower peripheral vision. There was no significant difference between left and right on average, with some volunteers better on the left and others on the right.
In the same task, participants were also asked to move their eyes to where the center of the middle clock had been once it disappeared. There was a strong correlation between the amount of disruption from clutter and the ability of individuals to make precise eye movements to those same locations.
“Everyone has their own pattern of sensitivity, with islands of poor vision and other regions of good vision,” Greenwood said. “If you’re looking for your keys, then this profile will affect your ability to find them. For example, if your keys are on a table to the left of where you’re focusing, the presence of books and papers on the table may stop you spotting the keys. Someone with strong left-sided vision could spot the keys even if they’re right next to the book, whereas someone else might not notice the keys unless they’re a foot away from the book. There is substantial variation between different people.”
These “islands” of poor vision were apparent across several tasks tested by the researchers, despite each relying on different processes in the brain. The implication is that these differences in peripheral vision could occur very early in the visual system, possibly beginning as early as the retina. It is unclear whether these differences are due to genetics or environment, but they are observed consistently over time.
Levels Of Vision
“What is striking is the consistency of the pattern from the first levels of vision up to the highest levels, processing that involves very different areas of the brain,” says senior author Professor Patrick Cavanagh, Dartmouth College. “We propose that these variations originate at the first levels of vision very early in our development where simple features like edges and colors are registered, and then are inherited by higher levels as the rest of the brain wires itself up to deal with the information being sent from the eyes. The higher levels deal with recognizing objects, faces, and actions, and directing our eyes toward areas of interest.”
Most people do not experience visual crowding in the center of their vision, unlike the periphery, however in some conditions central vision is also affected. In amblyopia – also known as “lazy eye” – the brain does not interpret visual signals from one eye properly, leading to an increase in visual crowding. In dyslexia, some research has shown that people with the condition find it easier to read words when the letter spacing is increased to reduce visual crowding. Similarly, visual crowding effects may be one of the early symptoms of Posterior Cortical Atrophy, a form of dementia that predominantly affects vision. Crowding is also a factor in macular degeneration, the most common form of blindness, where the center of the eye is affected first and so patients must rely on their peripheral vision to see.
“Our paper helps us to better understand the mechanisms that cause visual crowding and where these occur in the visual system,” Cavanagh added. “In the long term, we hope that this will help with the development of better treatment strategies for a wide range of conditions that limit the usefulness of vision for millions of people worldwide.”
Beating Dry Eye Syndrome
Symptoms of dry eye syndrome – dry, red, itchy, gritty, sore eyes – are more common among contact lens wearers. A group of Stanford University researchers explored the mechanical interactions between the eye surface, the cornea and contact lenses. The group’s goal was to create better contact lenses that maximize comfort and alleviate dry eye symptoms. When developing biomaterial-based devices that are in direct contact with cells, like contact lenses, their mechanical interaction with cells, biomaterial adhesion to cells and biocompatibility are all extremely important factors.
“Our system, a live-cell monolayer rheometer, is built on a standard inverted microscope for cell biology,” says Juho Pokki, a postdoctoral research fellow in the chemical engineering department at Stanford University. “It can simultaneously observe the cells and test cell mechanisms and adhesion.” Additionally, the group created an automated system to enable controllable experiments at the microscale. Cornea cell surfaces consist of a mechanically complex, soft material which you can think of as nature’s “smart material.” It has properties that depend on stress-strain conditions and time. Corneal cell mechanics and cell adhesion are altered for different corneal surface conditions, such as changes caused by disease, and different contact lenses.
By measuring mechanics and cellular or bacterial adhesion-related information, the group can compare biocompatible materials that are most suitable for contact lenses or for developing new biomedical devices such as prosthetic electronic skin. One of the group’s key findings was that corneal surface cells, which have adapted to protect the eye surface, are mechanically complex. “Their effective mechanical behavior is different between small and large strain conditions,” Pokki said. This behavior may be caused by changes within the cells.
In terms of applications, Pokki said, “beyond developing better contact lenses, our system can be used to screen and find optimal contact lens solutions or eye drops for people who have dry eye symptoms. This would allow people with dry eye syndrome to use contact lenses while maintaining corneal mechanics and adhesion similar to those of users without dry eye symptoms.”