by Maureen Duffy
Earlier this year, Google unveiled a prototype "smart" contact lens to monitor blood glucose levels contained in human tears. The Smart Contact Lens Project, which had been percolating in the top-secret Google X lab for several years, debuted a potential, although long-term, solution for effective blood glucose control in people with diabetes.
January 2014: Google Unveils the Smart Contact Lens
You've probably heard that diabetes is a huge and growing problem—affecting one in every 19 people on the planet. But you may not be familiar with the daily struggle that many people with diabetes face as they try to keep their blood sugar levels under control. Uncontrolled blood sugar puts people at risk for a range of dangerous complications, some short-term and others longer term, including damage to the eyes, kidneys, and heart.
Although some people wear glucose monitors with a glucose sensor embedded under their skin, all people with diabetes must still prick their fingers and test drops of blood throughout the day. It's disruptive, and it's painful. And, as a result, many people with diabetes check their blood glucose less often than they should.
A contact lens with embedded circuitry
to monitor blood glucose levels (Source: Google)
We're now testing a smart contact lens that's built to measure glucose levels in tears using a tiny wireless chip and miniaturized glucose sensor that are embedded between two layers of soft contact lens material. … It's still early days for this technology, but we've completed multiple clinical research studies which are helping to refine our prototype. We hope this could someday lead to a new way for people with diabetes to manage their disease.
We're in discussions with the FDA, but there's still a lot more work to do to turn this technology into a system that people can use. We're not going to do this alone: we plan to look for partners who are experts in bringing products like this to market. These partners will use our technology for a smart contact lens and develop apps that would make the measurements available to the wearer and their doctor.
July 2014: Google Unveils a Partnership with Novartis/Alcon
Last week, Google released additional information about the progress of the Smart Contact Lens Project, outlining a partnership with the European drug maker Novartis. Here is an excerpt from that announcement, via The New York Times:
Novartis said that Alcon, its eye care unit, had struck a deal to license so-called smart lens technology from one of Google's research divisions. As part of the agreement, Alcon said it would look to create products from Google's prototype smart contact lens, which uses miniature sensors and a radio antenna thinner than a human hair to track glucose levels.
Information about blood sugar levels, which is particularly useful for people with diabetes, could be uploaded to smartphone devices and used by doctors and patients to monitor the data almost in real time, according to a statement from Google issued when the company released its prototype in January.
Joe Jimenez, the chief executive of Novartis, acknowledged in an interview that many previous attempts to develop noninvasive glucose tests had failed, noting that the company previously tried — and failed — to develop its own glucose-monitoring contact lenses several years ago.
What makes this case different is the involvement of Google's engineers, he said. "One of the biggest hurdles was miniaturization, and that's one of the biggest benefits that Google X brings," he said. "This is a set of engineers that are really doing incredible things with technology."
Please note: The prototype smart contact lens must undergo many rounds of rigorous testing, via human clinical trials, before it can be determined if it is accurate, safe, and effective. In addition, since it is a medical device, the lens must receive FDA approval before it can be marketed and widely distributed.
More about Blood Glucose Levels and Diabetes from VisionAware
Research has shown that maintaining blood glucose levels within an acceptable range can lower and delay your risk for complications. You and your physician must decide together what blood glucose levels are achievable for you, based upon your age, abilities, medical status, personal needs, and any other special circumstances.
The current acceptable blood glucose target ranges set by the American Diabetes Association (ADA) are as follows:
- Fasting/pre-meal: between 70 and 130 mg/dL
- One to two hours after meal: below 180 mg/dL
It is important to remember that the purpose of your blood glucose readings is to let you know how close you are to your target range. Try not to label your readings as either "bad" or "good"; instead, think of them as indicators that describe (a) which aspects of your treatment are working for you and (b) which aspects need to be changed.
Two major studies that support the importance of blood glucose control are The Diabetes Control and Complications Trial for type 1 diabetes and the United Kingdom Prospective Diabetes Study for type 2 diabetes.
What Is Hyperglycemia?
Hyperglycemia rrefers to chronically high blood glucose levels. Most medical professionals define hyperglycemia by using the blood glucose goals that you and your physician have established and combining those goals with the blood glucose target ranges set by the ADA.
Symptoms of hyperglycemia can include the following:
- Dry, parched mouth
- Extreme thirst
- Frequent urination
- General weakness
- Fruity breath
- Nausea and vomiting
- Abdominal pain
- Deep, rapid breathing
Persistent hyperglycemia can cause a wide range of chronic complications that affect almost every system in your body. When large blood vessels are affected, it can lead to:
- Stroke (cerebral vascular disease)
- Circulation disorders and possible amputation (peripheral vascular disease)
- Heart attack or Congestive Heart Failure (coronary heart disease)
When smaller blood vessels are affected, it can lead to:
- Kidney disease (nephropathy)
- Nerve damage (neuropathy)
- Eye disease (retinopathy)
You can reduce your risk factors for complications related to hyperglycemia by doing the following:
- Maintaining your blood glucose levels within a normal range
- Keeping your blood pressure under control
- Controlling your blood fats (cholesterol and triglycerides)
- Avoiding/stopping smoking
- Increasing your physical activity
- Avoiding excess alcohol consumption
- Developing healthy eating habits and losing weight if necessary
What Is Hypoglycemia?
Hypoglycemia refers to dangerously low blood glucose levels that drop below 70 mg/dL. It is an acute complication of diabetes and occurs in individuals who use insulin or specific kinds of oral diabetes medication. If you use oral diabetes medications, ask your physician or diabetes educator whether hypoglycemia should be a concern.
Symptoms of hypoglycemia can include the following:
- Rapid pulse
- Shakiness, dizziness, weakness
- Decreased coordination
- Difficulty concentrating
- Blurred vision
- Trouble performing routine tasks
To treat hypoglycemia, you must immediately:
- Check your blood glucose level to determine the amount of carbohydrate that is needed to raise your blood glucose to a safe level.
- Use the 15/15 Rule: Consume 15 grams of carbohydrate (4 ounces of regular juice or soda, 1 tablespoon honey, 2 tablespoons raisins, 7 Life Savers®, 9 Sweet Tarts®, or 3-4 glucose tablets) and retest your blood glucose in 15 minutes.
- If it is still below 70 mg/dL, you should consume an additional 15 grams of carbohydrate.
- If you are not planning to have a meal within one to two hours after treating a hypoglycemic reaction, eat a snack containing 15-30 grams of carbohydrate to prevent another episode of hypoglycemia.
Other tips for managing hypoglycemia include:
- Keeping glucose-containing products close by at all times.
- Labeling sugar-free products, in a format of your choosing, to distinguish them from regular products.
- Making sure you can test your own blood glucose, measure insulin accurately, and determine recommended food portions to help prevent and properly treat low blood glucose.
- Wearing diabetes identification at all times.
by Maureen Duffy
Robert Wall Emerson, Ph.D., is a professor in the Department of Blindness and Low Vision Studies at Western Michigan University (WMU) in Kalamazoo. Dr. Wall Emerson, in conjunction with WMU colleagues Dae Shik Kim, Ph.D. (the principal investigator) and Koorosh Naghshineh, Ph.D., is the recent recipient of a $421,125 grant award from the National Institutes of Health/National Eye Institute.
The three-year grant, entitled Better long cane design and biomechanics for blind cane users, will examine the construction and most efficient use of the long white cane, used worldwide as a mobility device by people who are blind or have low vision.
Dr. Wall Emerson began his academic career in Canada, where he taught English and science. He then worked in special education as an itinerant vision teacher in northern Manitoba before moving to the United States for his orientation and mobility (O&M) and Ph.D. studies at Vanderbilt University in Nashville, Tennessee.
His research interests are broad and span a wide range of topics, including accessible pedestrian signals; acoustics in blind navigation; braille literacy; braille reading; the biomechanics [i.e., the study of the mechanics of movement] of long cane use; describing math images for blind students; strategies for increasing drivers' yielding behaviors at street crossings; and winter travel techniques for people with visual impairments.
Maureen Duffy: Hello, Dr. Wall Emerson. I appreciate your taking the time to speak with us about your new grant award. To start, can you tell us about the history of the long white cane, including its design as we know it today?
Robert Wall Emerson: Sure. The history of the long cane is itself long – but also is a history without a lot of changes until more recently. People who are blind have been using some sort of rod or staff to aid in their mobility for millennia, but the modern long cane was developed in the 1920s and 1930s.
There were some initial developments in the United Kingdom, but the first appearance of a modern cane for people who are blind, with white and red paint, was in the early 1930s in Peoria, Illinois. But these canes were made of wood and were fairly thick and sturdy, more like a regular walking cane.
It was during World War II that Dr. Richard E. Hoover thought to make aluminum cane shafts and created the modern cane we see today. More recently, people have started using carbon fiber or fiberglass for cane shafts. And of course there are now both rigid and folding – or telescoping – canes.
But the basic design of the cane has not changed appreciably for some time. One of the biggest innovations has been the range of cane tips that are now available.
MD: What are your goals for this research project? As I understand it, your research team is seeking to "improve the cane's ergonomic design and cane-use biomechanics to better detect obstacles and drop-offs in the walking environment." Can you explain those goals to our readers who use a cane for mobility or are thinking about using one?
RWE: We are not looking to redesign the cane. What we are looking at, however, is the different components of the cane – such as how the shaft material and the tip have an impact on the detection of obstacles and drop-offs. We are also looking at how changing the cane technique [i.e., the way a person uses the cane] has an impact on these detections. We are measuring several biomechanical aspects of body movement in order to track how the cane is used.
MD: In my role as VisionAware's social media specialist, I read about many research projects every week that are proposing to "improve the antiquated white cane" or "do away with the white cane because it is outdated technology." How would you respond to those researchers? And how is your research different?
RWE: We recognize that the long cane is the most commonly used and universal mobility aid used by people who are blind. The simplicity of its design means that it can be generalized to a wide range of tasks and environments, and with foldable or telescoping shafts, a cane need not be in the way when not in use.
The cane's basic design works well. I think that most modern cane travelers would also benefit from some sort of technology, such as a GPS device or phone app, but the long cane will always be a useful tool. And I do not think that attaching technology to a cane tends to be a workable solution. I tend to prefer hand-held assistive devices that can be put away when not in use.
MD: Can you tell us about your other research interests? I'm particularly interested in your work on the effect of hybrid or "quiet" vehicles on people's orientation and mobility skills – and I'm also interested in your research on accessible pedestrian signals.
RWE: I have done a fair bit of research in both of those areas. With my colleagues Dae Kim and Koorosh Naghshineh, as well as some earlier work with Bill Wiener and Julie Hapeman, we have looked at many aspects of how quieter vehicles have an impact on O&M and independent travel. Of course, most people now recognize that these vehicles are an increased threat at slow speeds, when backing up, or when turning. But what can we do about it?
Some of our research has fed into the forthcoming suggestions by the National Highway Traffic Safety Administration for addressing the issue. But for the typical blind traveler, it is difficult to link our research to actions they can take to reduce the threats from "quiet" cars. One of the main things that needs to be done, I think, is that pedestrians who are blind need to recognize what risks exist in a given situation and be okay with that level of risk.
I also think that O&M instructors need to do a good job of teaching risk assessment to their clients. Crossing a street when the environment is "all quiet" does not equate with "safe." That does not mean this strategy should never be used, but it should be used when appropriate – and even then there are risks associated with the crossing.
Accessible Pedestrian Signals (APS) are a great example of something that can address the quiet car issue. At intersections where APS are installed, they can offer the kind of support that a pedestrian who is blind can use, even when other acoustic cues are not available, such as when there are only quiet cars around.
However, O&M instructors must also recognize a new type of procedure to use when crossing at an intersection with push buttons (with or without APS):
- The pedestrian needs to establish his or her crossing place and find some sort of anchor to remember the spot.
- The pedestrian then scans with the cane left and right for a pole if there is no APS installed; otherwise the pedestrian walks to the pole with the APS locator tone.
- The pedestrian waits until the parallel surge of traffic starts and then pushes the button to activate the traffic signal controller. This will provide the pedestrian with a parallel traffic phase and a subsequent perpendicular traffic phase before the walk indicator signal will sound.
- After activating the traffic signal controller, the pedestrian returns to the crossing place, re-establishes alignment, and crosses with the next parallel traffic surge and when the auditory walk signal sounds.
MD: What do you regard as the next great frontier in independent outdoor travel for people who are blind or have low vision?
RWE: I think it's important for O&M instructors to engage on a large scale with traffic engineers so that they can have an impact on the travel environment and make it more accessible. This might lead to changes in the environment itself that we cannot yet foresee. For example, if driverless cars are truly around the corner, then perhaps we are not too far from a fully integrated environment that allows pedestrians to flow seamlessly into traffic with much less risk.
We thank Dr. Wall Emerson for his support of VisionAware and for his continuing research on behalf of blind and visually persons. You can read more about Dr. Wall Emerson's ongoing research at the Western Michigan University Discovery Experts Database.
Additional Orientation and Mobility Information
by Maureen Duffy
Results from a new clinical trial, presented at the July 2014 Alzheimer's Association International Conference, suggest that cataract surgery may slow mental decline in people with Alzheimer's disease and related dementias. Preliminary study results indicate that improved vision, resulting from cataract surgery, can have a variety of benefits – both visual and non-visual – for people with dementia.
The research, entitled Visual and cognitive improvement following cataract surgery in subjects with dementia, funded by the National Institute on Aging, was presented on July 13, 2014, at the Alzheimer's Association International Conference in Copenhagen, Denmark.
The study authors are Alan Lerner; Sara Debanne; Julie Belkin; Jon Lass; Tatiana Riedel; Thomas Steinemann; Susie Sami; and Grover Gilmore, who represent the following institutions: Case Western Reserve University; University Hospitals Case Medical Center; and MetroHealth Medical Center in Cleveland, Ohio.
The Alzheimer's Association International Conference (AAIC) is the world's largest gathering of leading researchers from around the world focused on Alzheimer's and other dementias. As a part of the research program of the Alzheimer's Association, AAIC serves as a catalyst for generating new knowledge about the cause, diagnosis, treatment, and prevention of Alzheimer's disease and related disorders.
About the Research
From For People with Dementia, Cataract Surgery Improves Not Only Vision but Cognition and Quality of Life, via the Alzheimer's Association:
"This study supports the Alzheimer's Association view that people with dementia retain, and benefit from, full healthcare treatment," said Maria Carrillo, Ph.D., Alzheimer's Association vice-president of Medical and Scientific Relations. "Too common attitudes such as, 'There's no need for extra care' or 'Why put them through all of that' are not justified and are bad medical practice."
"Appropriate thoughtfulness and restraint are necessary when considering surgery or other procedures for people with Alzheimer's or another dementia. However, we should not assume that medical procedures cannot be pursued or are too risky. As these new results show, improving sensory abilities, for example, can provide benefits in a variety of ways – for people with Alzheimer's and also for their caregivers from whom unnecessary burden can be lifted," Carrillo said.
Study participants were recruited from dementia and ophthalmology clinics at University Hospitals Case Medical Center and MetroHealth Medical Center in Cleveland, Ohio, and were divided into two groups: (1) immediate surgery following recruitment and (2) delayed or refused surgery. Vision and cognitive status, mood, and capability to complete daily activities were evaluated at baseline and six months after recruitment, or six months after surgery.
Preliminary analysis of results from 20 surgical and eight non-surgical participants showed that the surgical group had significantly improved visual acuity and quality of life, reduced decline in memory and executive functioning, and improvements in behavioral measures compared with the non-surgical group. Levels of perceived burden for caregivers of people in the surgical group also showed improvement.
Cataracts and Cataract Surgery
To date, no medication or eye drop has been proven to prevent or reverse cataract formation. If a cataract is causing nearsightedness or a change in an individual's prescription, new prescription eyeglasses can help improve blurred vision. The only treatment for a cataract, however, is surgical removal of the natural lens.
When to Remove? Sooner or Later?
A cataract should not be removed simply because it is present. Many people have cataracts that do not cause blurred vision, interfere with activities of daily living, or otherwise prevent them from leading active and productive lives. In such cases, these individuals should not undergo unnecessary surgery to remove their cataracts.
However, if an individual has a cataract and resultant blurred vision that makes it difficult to read or continue the daily activities that he or she wants and needs to do, it is time to consider cataract surgery.
If there are cataracts in both eyes that require surgery, the surgeries are usually performed several weeks apart. Cataract surgery on both eyes at the same time is not recommended because there is a possibility of complications affecting both eyes – the most worrisome complication is infection.
How Much Should the Cataract Develop Before Having Surgery?
A cataract does not have to become "ripe" before it can be removed. In the past, the lens could not be extracted safely from the eye unless it was at a relatively advanced stage of development. With modern advances in cataract surgery, however, the lens can now be removed from the eye at any stage of development.
It is true that the longer a cataract develops, the more it hardens. At advanced stages, a firmer or more developed cataract can be difficult to remove. In certain situations, it is safer to remove a cataract sooner rather than later; in most cases, however, an individual should not undergo cataract surgery unless he or she is experiencing blurred vision caused by the cataract.
It is also true that if cataracts are allowed to develop for long periods of time, they can cause inflammation or increased intraocular (within the eye) pressure that can lead to glaucoma.
In these situations, it is extremely important to remove the cataract to prevent loss of vision from the resultant inflammation or glaucoma. This scenario rarely occurs in the United States, however, due to regular access to most types of health care.
More about the Study from AAIC
From the presentation abstract:
Background: Medical co-morbidities [i.e., co-existing medical conditions] often lead to disproportionate adverse effects in dementia. Cataracts are a prominent age related-comorbidity, often co-occurring with Alzheimer's disease (AD) or dementia. The utility of cataract removal in AD in terms of improving visual acuity and Quality of life (QoL) are unknown.
Considerations for surgical removal include the possibility that improved vision may contribute to better cognitive status. Conversely, since AD is a brain disease, improving peripheral sensory input may not materially affect brain function.
Furthermore, the safety risks and potential surgical complications in demented individuals may be sufficiently great to warrant appropriate reticence among treating physicians and ophthalmologists.
To address these questions, we are conducting a clinical trial to determine the effects of cataract removal on visual acuity, spatial contrast sensitivity, vision dependent functions, visual information processing, cognitive measures and QoL in patients with dementia.
Methods: Patients were recruited from dementia and ophthalmology clinics at University Hospitals Case Medical Center and Metro Health Medical Center. Forty-three participants have been enrolled with recruitment ongoing. The current analysis includes 28 protocol completers: 20 in the surgery group, 8 in the non-surgery group.
Conclusions: Our preliminary results show that cataract surgery can improve visual acuity and visual QoL, while reducing decline in memory, and executive function and showing improvements in behavioral measures. Our findings suggest the need to aggressively address dementia co-morbidities such as cataract impairing vision while balancing safety and medical risks.
Preliminary Results and Future Research
According to lead study author Dr. Alan Lerner, "These preliminary results indicate that improved vision can have a variety of benefits for people with dementia and their loved ones, both visual and non-visual. Our findings need to be verified in a larger study, but they suggest the need to aggressively address dementia co-morbidities such as vision-impairing cataracts, while balancing safety and medical risks."
"If the results hold up, it will significantly affect how we treat cataracts in individuals with dementia. Other interventions to offset sensory loss – including vision and hearing – may help improve quality of life for people with dementia and their caregivers," Lerner added.
by Maureen Duffy
Researchers from the United States and China have demonstrated that (a) acute glaucoma in mice presents as an inflammatory disease and (b) elevated eye pressure causes vision loss by setting in motion an inflammatory response similar to that evoked by bacterial infections.
This research is in its earliest stages and has been conducted only with laboratory mice. Nevertheless, the concept shows great promise for persons with acute glaucoma.
The research, entitled Caspase-8 promotes NLRP1/NLRP3 inflammasome activation and IL-1ß production in acute glaucoma (explained below) was published in the July 14, 2014 Early Edition of Proceedings of the National Academy of Sciences. Proceedings, first published in 1915, is the official journal of the United States National Academy of Sciences. It publishes research reports, commentaries, and reviews that span the biological, physical, and social sciences.
The authors are Wei Chi; Fei Li; Hongrui Chen; Yandong Wang; Yingting Zhua; Xuejiao Yang; Jie Zhu; Frances Wu; Hong Ouyang; Jian Ge; Robert N. Weinreb; Kang Zhang; and Yehong Zhuo, who represent the following institutions: Sun Yat-sen University, Guangzhou, China; and the Shiley Eye Center, University of California, San Diego, La Jolla.
About Acute Glaucoma and Inflammation Research
From Acute glaucoma discovered to be an inflammatory disease, via Medical Xpress:
"Our research is the first to show an inflammatory mechanism by which high ocular pressure causes vision loss in acute glaucoma patients," said co-senior author Kang Zhang, MD, PhD and professor of ophthalmology.
Less than 10 percent of glaucoma patients in America have the closed-angle [i.e., acute] form, but in parts of Asia it accounts for almost half of all cases. The higher prevalence of closed-angle glaucoma in Asians and women is believed to be due to a shallower anterior (frontal) eye chamber.
In the study, researchers showed that a rapid, sustained large increase in eye pressure in mice turns on a gene (TLR4) that activates a protein known as caspase-8. This signaling protein in turn triggers the production of inflammatory proteins that normally help mammals fight microbial infections [i.e., a microorganism, especially a bacterium that causes disease].
"This immune response is a double-edged sword because, while these proteins protect us from infection in a normal situation, they stimulate apoptosis (programmed cell death) in retinal cells in cases of acute glaucoma," said Zhang.
To further confirm the mechanism linking high eye pressure to retinal damage, researchers showed that they could slow retinal cell death in mice with acute glaucoma by suppressing either the TLR4 gene or caspace-8 protein.
The latter is particularly significant because caspace-8 inhibitors are currently in clinical trials for treating cancer and stroke. "By injecting these inhibitors into the eyes of acute glaucoma patients, it may be possible to evaluate and bring them vision-sparing treatments more quickly," said co-author Robert N. Weinreb.
What Is Glaucoma?
The term "glaucoma" describes a group of eye diseases that can lead to blindness by damaging the optic nerve. It is one of the leading causes of vision loss and blindness. The human eye continuously produces a fluid, called the aqueous, that must drain from the eye to maintain healthy eye pressure.
Types of Glaucoma
In primary open-angle glaucoma, the most common type of glaucoma, the eye's drainage canals become blocked, and the fluid accumulation causes pressure to build within the eye. This increasing pressure can cause damage to the optic nerve, which transmits information from the eye to the brain. Vision loss is usually gradual and often there are no early warning signs.
In angle-closure glaucoma, also called "acute" glaucoma, the aqueous cannot drain properly because the entrance to the drainage canal is either too narrow or is closed completely. In this case, eye pressure can rise very quickly and cause an acute glaucoma attack. Symptoms can include sudden eye pain, nausea, headaches, and blurred vision. Acute glaucoma is a true ocular emergency and requires immediate treatment.
In normal-tension glaucoma, also called low-tension/low pressure glaucoma, individuals with the disease experience optic nerve damage and subsequent vision loss, despite having normal intraocular [i.e., within the eye] pressure (IOP).
Most eye care professionals define the range of normal IOP as between 10 and 21 mm Hg [i.e., millimeters of mercury, which is a pressure measurement]. Most persons with glaucoma have an IOP measurement of greater than 21 mm Hg; persons with normal-tension glaucoma, however, have an IOP measurement within the normal range.
Visual Field Loss
Glaucoma results in peripheral (or side) vision loss initially, and the effect as this field loss progresses is like looking through a tube or into a narrow tunnel. This constricted "tunnel vision" effect makes it difficult to walk without bumping into objects that are off to the side, near the head, or at foot level.
A living room viewed through a constricted visual field.
Source: Making Life More Livable. Used with permission.
Glaucoma is an especially dangerous eye condition because most people do not experience any symptoms or early warning signs at the onset. Glaucoma can be treated, but it is not curable. The damage to the optic nerve from glaucoma cannot be reversed.
More about the Study from Proceedings of the National Academy of Sciences
From the study summary and abstract:
Acute glaucoma is a sight-threatening condition characterized by a sudden and substantial rise in intraocular pressure (IOP) and consequent retinal ganglion cell death. [Note: Ganglion cells are a type of nerve cell that is found in the retina.]
Angle closure glaucoma, a common cause of glaucoma in Asia that affects tens of millions of people worldwide, often presents acutely with loss of vision, pain, and high IOP.
Even when medical and surgical treatment is available, acute angle closure glaucoma can cause permanent and irreversible loss of vision. TLR4 signaling has been previously implicated in the pathogenesis [i.e., the mechanisms that cause it] of IOP-induced retinal ganglion cell death, although the underlying mechanisms are largely unknown.
In the present study, we used an acute IOP elevation/glaucoma model to investigate the underlying mechanism of retinal ganglion cell death … This study demonstrates the critical role of caspase-8 in IOP-induced cell death in rodent models of acute glaucoma.
These findings identify a mechanism of retinal ganglion cell death and provide a previously unidentified treatment strategy to preserve vision in acute glaucoma.
VisionAware will provide updates of this glaucoma research as they become available.
More Glaucoma and Inflammation Research
by Maureen Duffy
The first clinical trial to examine integrated low vision and mental health treatment – bridging ophthalmology, optometry, psychiatry, psychology, and rehabilitation – has demonstrated that an interdisciplinary rehabilitation program can reduce the incidence of depression by half among older adults with low vision due to age-related macular degeneration (AMD).
Ophthalmology: the Journal
The research, entitled Low Vision Depression Prevention Trial in Age-Related Macular Degeneration, has been published online ahead-of-print on July 9, 2014 in Ophthalmology, the official journal of the American Academy of Ophthalmology.
The authors are Barry W. Rovner, MD; Robin J. Casten, PhD; Mark T. Hegel, PhD; Robert W. Massof, PhD; Benjamin E. Leiby, PhD; Allen C. Ho, MD; and William S. Tasman, MD, who represent the following institutions: Jefferson Medical College, Philadelphia, PA; Dartmouth Medical School, Lebanon, NH; and Johns Hopkins School of Medicine, Baltimore, MD.
About the Research
"Our results emphasize the high risk of depression from AMD, and the benefits of multi-disciplinary treatment that bridges primary eye care, psychiatry, psychology, and rehabilitation," said Barry Rovner, M.D., a professor of psychiatry and neurology at Thomas Jefferson University in Philadelphia.
"The depression is a response to disability, so we reasoned an effective treatment would be to reduce the disability through rehabilitation," Dr. Rovner said. In the Low Vision Depression Prevention Trial (VITAL), he led a team of psychologists, ophthalmologists, optometrists, and occupational therapists to test an approach called behavior activation.
"Behavior activation involves helping people to focus on activities they enjoy, to recognize that loss of those activities can lead to depression, and to re-engage in those activities," said Robin Casten, Ph.D., a co-author and an associate professor of psychiatry and human behavior at Jefferson. Helping people maintain an active social life is an important part of the approach, she said.
The trial recruited 188 participants with bilateral [i.e., in both eyes] AMD from an ophthalmology practice affiliated with Wills Eye Hospital in Philadelphia. The participants were 84 years of age on average, 70 percent were women, and 50 percent lived alone. All had a best-corrected visual acuity of less than 20/70.
Each participant had mild depressive symptoms and was at risk for developing clinical depression, based on a nine-item depression subtest of the Patient Health Questionnaire.
During the trial, each participant had two visits with an optometrist, during which they were prescribed low vision devices, such as hand-held magnifiers. After those initial visits, the participants were randomly divided into two groups for two different interventions (described below).
[After four months], 18 (23.4 percent) in the control group and 11 (12.6 percent) in the behavior activation group developed clinical depression. Behavior activation had the most benefit for participants with the worst vision (less than 20/100), reducing the risk of depression by about 60 percent compared to [the control group].
When the data were adjusted for vision status, physical health, and baseline [depression] score, behavior activation reduced the risk of depression by 50 percent compared to the control treatment.
As described in the Low Vision Depression Prevention Trial for Age Related Macular Degeneration, the two interventions were as follows:
Behavior Activation + Low Vision Rehabilitation (The Active Treatment)
- Also called Collaborative Low Vision Rehabilitation (optometrist and home-based occupational therapist)
- Used low vision clinic-based optometry, plus six in-home occupational therapy visits
- A low vision occupational therapist (OT) delivered Behavior Activation, a psychological treatment to prevent depression.
- The optometrists evaluated vision and magnification needs, prescribed low vision optical devices, and provided the OTs with initial care plans.
- The OTs met with participants in their homes six times over 12 weeks to enhance low vision device use, home modifications, and compensatory strategies, such as increasing social activities, setting personal goals, and breaking goals down into manageable steps.
Supportive Therapy + Low Vision Rehabilitation (The Placebo or Comparison)
- Also called Enhanced Low Vision Rehabilitation (optometrist and home-based Supportive Therapy)
- Used low vision clinic-based optometry, plus six in-home Supportive Therapy sessions over 12 weeks
- Supportive therapy is a placebo treatment that controls for the attention the participants in the active treatment group received.
- [Editor's note: In research terminology, a placebo is an intervention or a drug that has no therapeutic effect or contains no active medication.]
About Low Vision
Low vision is uncorrectable vision loss that interferes with daily living activities. It is better defined in terms of function, rather than [numerical] test results. In other words, low vision is "not enough vision to do whatever it is you need to do," which can vary from person to person.
Most eye care professionals use the term "low vision" to describe permanently reduced vision that cannot be corrected with regular glasses, contact lenses, medicine, or surgery. One of the primary causes of low vision is AMD.
You can learn more about low vision at Low Vision and Legal Blindness Terms and Descriptions and What is a Low Vision Examination? on the VisionAware website.
What are Low Vision Rehabilitation Services?
Vision rehabilitation services enable adults who are blind or have low vision to continue living independently. The terms "vision rehabilitation" and "low vision rehabilitation" include highly trained professionals and comprehensive services that can restore function after vision loss, just as physical therapy restores function after a stroke or other injury.
In addition to the interventions described in the VITAL Trial, the full range of vision rehabilitation services and professionals includes the following:
- Low Vision Therapists: teach the use of residual vision with optical devices, non-optical devices, and assistive technology, and help determine the need for environmental modifications in the home or workplace.
- Vision Rehabilitation Therapists: teach adaptive independent living skills that enable adults to perform a wide range of daily activities, including meal preparation, reading and writing, home repair, personal self-care, and financial management.
- Orientation and Mobility Specialists: teach safe and independent indoor and outdoor travel skills, including the use of a long cane, electronic travel devices, public transportation, human guide techniques, and pre-cane skills.
Additional vision rehabilitation services can include:
- Peer support and counseling: talking with peers, sharing common concerns and frustrations, and finding solutions to vision-related problems
- Vocational rehabilitation: vocational evaluation and training, job training, job modification and restructuring, and job placement
- Veterans' services: vision rehabilitation and related support services for blinded veterans of all ages.
More about the Low Vision Depression Prevention Trial Study Results
From the article abstract:
Purpose: To compare the efficacy of behavior activation + low vision rehabilitation with supportive therapy + low vision rehabilitation to prevent depressive disorders in patients with age-related macular degeneration.
Interventions: Before randomization, all subjects had two outpatient low vision rehabilitation visits, and were then randomized to in-home behavior activation + low vision rehabilitation or supportive therapy + low vision rehabilitation.
Behavior activation is a structured behavioral treatment that aims to increase adaptive behaviors and achieve valued goals. Supportive therapy is a nondirective, psychological treatment that provides emotional support and controls for attention.
Results: At four months, 11 behavior activation + low vision rehabilitation subjects (12.6%) and 18 supportive therapy + low vision rehabilitation subjects (23.4%) developed a depressive disorder.
A mediational analysis suggested that behavioral activation + low vision rehabilitation prevented depression to the extent that it enabled subjects to remain socially engaged.
In addition, behavioral activation + low vision rehabilitation was associated with greater improvements in functional vision than supportive therapy + low vision rehabilitation, although there was no significant between-group difference. There was no significant change or between-group difference in quality of life.
Conclusions: An integrated mental health and low vision intervention halved the incidence of depressive disorders relative to standard outpatient low vision rehabilitation in patients with AMD.
As the population ages, the number of persons with AMD and the adverse effects of comorbid [i.e., coexisting] depression will increase. Promoting interactions between ophthalmology, optometry, rehabilitation, psychiatry, and behavioral psychology may prevent depression in this population.
As summarized by Dr. Barry Rovner in Science Codex, "Our findings demonstrate that referring patients with AMD-related low vision for low vision optometric rehabilitation alone does not fully meet the patients' rehabilitative needs. Although low vision occupational therapists do not currently receive training in mental health care, our results indicate that interdisciplinary care like this could significantly help reduce the incidence of depression in patients with AMD."
Please note: The study is continuing to follow participants to determine if the benefits of treatment are maintained after one year.
How to Locate Low Vision Rehabilitation Services
The VisionAware Directory of Services allows you to browse by state and type of service, including counseling resources, support groups, low vision services, independent living skills, and orientation and mobility. The VisionAware "Getting Started" kit provides tip sheets on specialized services and products that can assist with everyday life after vision loss.
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