Age Related Macular Degeneration

From http://www.macularisk.com/about-amd/about-amd

About AMD
Introduction
Symptoms of AMD
Kinds of AMD
The Importance of Frequent Vision Testing

Introduction
Age-related macular degeneration (AMD) is the leading cause of severe vision loss among older adults in the Western world, affecting over 25 million people in the USA alone, primarily the elderly. The worldwide incidence of the disease grows from 1 in 10 people over the age of 60 to more than 1 in 4 people over the age of 75. There are close to 2 million with vision loss due to advanced AMD and more than 600,000 that are legally blind due to the disease in North America. According to the AMD Alliance, macular degeneration is more common than Parkinson’s disease, Alzheimer’s disease, Breast Cancer and Prostate cancer combined.

Age-related macular degeneration is a disease that damages the macula, the central portion of the area at the back of the eye called the retina. The macula allows for central vision and also lets you see color and fine detail—all of which are important to daily activities such as reading and driving. The macular damage caused by AMD causes central vision loss. In most cases, patients will retain peripheral vision and be able to see shapes, light and movement.

Image courtesy of the NEI.

Symptoms of AMD
Symptoms of Age-related macular degeneration (AMD) can include:

•A spot or hazy section blocking the center of someone`s vision
•Distortion or waviness when looking at an image
•Distortion of lines on the Amsler Grid
Changes in vision should trigger immediate evaluation from an eye doctor. For patients over the age of 50 with a family history of AMD or smokers – routine yearly eye exams are a must. Detection of the early signs of AMD is essential to help preserve as much of their vision as possible.

The majority of people with AMD have central scotomas. Scotomas are retinal areas with reduced light sensitivity compared to sensitivity results of normal sighted subjects. Scotomas are specified by the retinal location in that central scotomas are retinal areas with reduced light sensitivity involving the fovea, while paracentral scotomas are retinal areas with reduced light sensitivity within the central 20° of the visual field but not involving the fovea.

Kinds of Age-related macular degeneration
There are 2 kinds of age-related macular degeneration (AMD): dry and wet. Dry AMD is more common, representing approximately 90% of all AMD cases, and is generally not as damaging to vision as the wet form. Dry AMD can convert into wet AMD at any time.

AMD is also classified into different categories:

Category 1:Few small (< 63 micrometers [µm]) or no drusen
Category 2:Early AMD, having many small drusen or a few intermediate-sized (≥ 63 µm and <125 µm) drusen.
Category 3:Extensive intermediate drusen or at least one large (≥125 µm) drusen.
Category 4:Advanced AMD in 1 eye, either Geographic Atrophy (GA) in the center or neovascular AMD
Dry AMD
In dry AMD, yellowish, fatty deposits called drusen collect in the macula. Serious vision loss is rarely caused by dry AMD; however as many as 20% of Dry AMD patients will progress to wet AMD. There are no approved treatments for dry AMD, although vitamins, antioxidants and zinc supplements may slow its progression. Most dry AMD patients have no symptoms, and an eye doctor may need to conduct a variety of eye exams to aid in diagnosis.

Genetic risk for AMD may predict the therapeutic benefit of vitamins and nutritional supplements. A longitudinal Dutch study has determined that individuals with the CFH and ARMS2 risk alleles benefit from diets rich in nutrients known to slow the progression of AMD while progression in those without genetic risk factors appears to be independent of diet.

Wet AMD
Wet AMD occurs when abnormal blood vessels grow under the retinal center. These may be very fragile and leak blood and fluid. This process can damage the macula or create a retinal scar.

Due to the rapid onset of macular damage, a noticeable blurring or even loss of central vision are frequently the first symptoms noted. The vision loss may be permanent because abnormal blood vessels and scar tissue are actually destroying normal retinal tissue. Once lost, these light-sensitive cells in the retina cannot be replaced.

If a person has wet AMD in one eye, there is a 35% chance of contralateral wet AMD within 5 years. The most important action to preserve vision is to establish a schedule of regular retinal re-evaluation by an eye care professional.

The Importance of Frequent Vision Testing
The best defenses against vision loss due to AMD are:

•Regular eye exams
•Awareness of its warning signs
•Ongoing vision monitoring through self-examination
With eye exams & awareness, it is important to self-monitor for signs of AMD. Early vision changes often affect only 1 eye and occur gradually over time. One simple home-based test uses the “Amsler grid.”

The grid is placed 12 inches away at eye level in good lighting .

•Corrective lenses are worn if required. One eye is covered and vision is directed for 1 minute at the grid’s center dot
•A positive test is characterized by the perception of deviation in the regularity of the pattern
•Each eye should be tested separately
A positive test must elicit prompt eye evaluation.

While a useful adjunct, regular use of the Amsler grid cannot detect nascent vision loss and is not a substitute for regular eye exams and appropriate retinal imaging.

However, since only an eye doctor can determine if you have dry or wet AMD, Amsler grid self-examinations do not replace regular eye exams.

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Diet & Nutrition & Your Eyes

Adding powerful antioxidants to your diet can improve your eye health. There’s no substitute for the quality of life good vision offers. Adding certain nutrients to your diet every day – either through foods or supplements – can help save your vision. Researchers have linked eye-friendly nutrients such as lutein/zeaxanthin, vitamin C, vitamin E, and zinc to reducing the risk of certain eye diseases, including macular degeneration and cataract formation.

Lutein & Zeaxanthin
Lutein and zeaxanthin are important nutrients found in green leafy vegetables, as well as other foods, such as eggs. Many studies have shown that lutein and zeaxanthin reduce the risk of chronic eye diseases, including age-related macular degeneration and cataracts.

Vitamin C
Vitamin C (ascorbic acid) is an antioxidant found in fruits and vegetables. Scientific evidence suggests vitamin C lowers the risk of developing cataracts, and when taken in combination with other essential nutrients, can slow the progression of age-related macular degeneration and visual acuity loss.

Vitamin E
Vitamin E in its most biologically active form is a powerful antioxidant found in nuts, fortified cereals and sweet potatoes. It is thought to protect cells of the eyes from damage caused by unstable molecules called free radicals which break down healthy tissue.

Essential Fatty Acids
Fats are a necessary part of the human diet. They maintain the integrity of the nervous system, fuel cells and boost the immune system. Two omega-3 fatty acids have been shown to be important for proper visual development and retinal function.

Zinc
Zinc is an essential trace mineral or ‘helper molecule.’ It plays a vital role in bringing vitamin A from the liver to the retina in order to produce melanin, a protective pigment in the eyes. Zinc is highly concentrated in the eye, mostly in the retina and choroid, the vascular tissue layer lying under the retina.

Emerging Research
In the last 20 years, eye health research has linked diet and nutrition with a decreased risk of age-related macular degeneration (AMD).
Written in partnership with AOA members Stuart Richer, O.D., Ph.D., and Steven Newman, O.D.
The AOA acknowledges the support of Kemin and DSM Nutritional Products on this project. Kemin produces FloraGLO® Lutein, the trusted lutein ingredient brand among hundreds of multivitamins, eye formulas, supplements, foods and beverages throughout the world.

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Procedures of Normal Eye Exam

A normal eye exam starts with case history, reason for visit, chief complaint, history of present illness, patient health history, and going over the review of systems changes with the patient. Next we do an auto-refraction and entering acuities are taken. The patient is then refracted for their spectacle prescription. After the refraction is completed, the anterior segment of the eye is examined with the bio-microscope. That checks the cornea, iris, anterior changer and the pupil as it responds to light. The visual field is screened and any muscle deviation is noted. Ophthalmoscopy is then done with or without dilation to check the health of the interior of the eye. The diagnosis is made and the patients plan is set forward.

ADDED PROCEDURES FOR A CONTACT LENS EXAM (The reason ALL Optometrists charge a fitting fee)

Anterior readings of the curvature of the cornea are taken. The doctor determines the trial lens that would appear to be the best fitting and the conversion of the specticle Rx is put into a contact lens Rx. The doctor then puts the trial lens in the patients eyes and determines if the lens fit is optimal and the Rx is correct. Then makes any adjustments that might be needed.

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Dry Eye: When Tears Don’t Do Their Job

Teardrops serve an essential function for your eyes — they keep them moist and clean and provide them with essential nutrients. But when your eyes don’t produce enough, you may develop a condition known as dry eye.
By Dennis Thompson Jr.
Medically reviewed by Lindsey Marcellin, MD, MPH

Sine Tears aren’t just for crying. They are a vital part of maintaining healthy eyesight, always acting to moisturize and lubricate your corneas. If something happens to affect the amount or quality of the teardrops you produce, you could wind up with itchy, scratchy, aching eyes — symptoms of a condition known as dry eye syndrome.

The cornea is the dome-shaped invisible surface covering the parts of the eye that take in light and control vision — the iris and the pupil. The cornea protects those crucial eyesight mechanisms from outside contaminants like dust, germs, and debris. Because it covers the light-perceiving portions of the eye, the cornea is made of clear tissue. That means it contains no blood vessels to provide it nourishment or protect it from infection.

Instead, the cornea receives its nutrition from tears. Every time you blink, tears created by the lacrimal gland spread across your eyeballs. These tears act to lubricate the entire outer surface of the eyeball and keep your corneas clean and healthy. Tears also help wash away foreign matter that might damage the cornea, keep the cornea moist, and reduce the risk of eye infections. In emergency situations, like when an eyelash or dust particle lands on your eye, tear production increases,

Dry Eye: When You’re Not Producing Enough Tears

Dry eye syndrome occurs when:

Not enough tears are produced. For various reasons, including inflammation of the lacrimal glands, you don’t produce enough tears to keep your corneas properly fed and protected. Tears of insufficient quality are produced. Your tears contain a combination of oil, water, and mucus. The oil in tears works to “seal” the tears in and help prevent evaporation before the corneas have been fed and lubricated. Mucus works to make sure the tears spread evenly across the eye. If you are not producing enough oil or mucus, your tears may not be able to do their best at protecting the corneas. Symptoms of dry eye include:

A burning or stinging sensation in the eye A gritty feeling, as though something is in your eye Pain and irritation in your eye Blurred vision Eye fatigue, including the inability to read or work on a computer for extended periods What Causes Dry Eye?

Age is the most common risk factor for dry eyes. In fact, dry eye is considered a normal part of aging. Nearly 5 million Americans 50 or older have dry eye, including more than 3 million women and more than 1.5 million men. Dry eye tends to become more common in women following menopause, and women who go through premature menopause are more likely to have eye damage from dry eye.

Other causes of dry eye include:

Medications. Certain types of drugs can cause dry eye. These include antihistamines, decongestants, antidepressants, and blood pressure medications. Medical conditions. Eye or eyelid infections and diseases that cause inflammation can contribute to dry eye by affecting tear production, as can allergies. People with diabetes, rheumatoid arthritis, and thyroid problems are also at increased risk for dry eye. In addition, vitamin overuse or deficiency can be a contributing factor. Environmental conditions. Tears may evaporate more quickly when eyes are exposed to smoke, dry air, or wind — likely resulting in dry eye. Staring at a computer screen or television also can cause dry eye if you unconsciously start blinking less frequently. Eyesight correction. Long-term contact lens use can cause dry eye. People who have undergone laser vision correction also could experience dry eye because of a change in the shape of the cornea, which may have an effect on the spread of tears across the cornea. Dry eye can and should be treated for the health and comfort of your eyes.

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Get Ready for Spring and Summer With New Sunglasses!

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Bionic Vision Australia

“All of a sudden I could see a flash of light. It was amazing”

30 August 2012

In a major development, Bionic Vision Australia researchers have successfully performed the first implantation of an early prototype bionic eye with 24 electrodes.

Ms Dianne Ashworth has profound vision loss due to retinitis pigmentosa, an inherited condition. She has now received what she calls a ‘pre-bionic eye’ implant that enables her to experience some vision. A passionate technology fan, Ms Ashworth was motivated to make a contribution to the bionic eye research program.

After years of hard work and planning, Ms Ashworth’s implant was switched on last month at the Bionics Institute, while researchers held their breaths in the next room, observing via video link.

“I didn’t know what to expect, but all of a sudden, I could see a little flash…it was amazing. Every time there was stimulation there was a different shape that appeared in front of my eye,” Ms Ashworth said.

Professor Emeritus David Penington AC, Chairman of Bionic Vision Australia said: “These results have fulfilled our best expectations, giving us confidence that with further development we can achieve useful vision. Much still needs to be done in using the current implant to ‘build’ images for Ms Ashworth. The next big step will be when we commence implants of the full devices.”

Professor Anthony Burkitt, Director of Bionic Vision Australia said: “This outcome is a strong example of what a multi-disciplinary research team can achieve. Funding from the Australian Government was critical in reaching this important milestone. The Bionics Institute and the surgeons at the Centre for Eye Research Australia played a critical role in reaching this point.”

Professor Rob Shepherd, Director of the Bionics Institute, led the team in designing, building and testing this early prototype to ensure its safety and efficacy for human implantation. Cochlear technology supported aspects of the project.

Dr Penny Allen, a specialist surgeon at the Centre for Eye Research Australia, led a surgical team to implant the prototype at the Royal Victorian Eye and Ear Hospital.

“This is a world first – we implanted a device in this position behind the retina, demonstrating the viability of our approach. Every stage of the procedure was planned and tested, so I felt very confident going into theatre,” Dr Allen said.

The implant is only switched on and stimulated after the eye has recovered fully from the effects of surgery. The next phase of this work involves testing various levels of electrical stimulation with Ms
Ashworth.

“We are working with Ms Ashworth to determine exactly what she sees each time the retina is stimulated using a purpose built laboratory at the Bionics Institute. The team is looking for consistency of shapes, brightness, size and location of flashes to determine how the brain interprets this information.

“Having this unique information will allow us to maximise our technology as it evolves through 2013 and 2014,” Professor Shepherd said.

How it works

This early prototype consists of a retinal implant with 24 electrodes. A small lead wire extends from the back of the eye to a connector behind the ear. An external system is connected to this unit in the
laboratory, allowing researchers to stimulate the implant in a controlled manner in order to study the flashes of light. Feedback from Ms Ashworth will allow researchers to develop a vision processor so that images can be built using flashes of light. This early prototype does not incorporate an external camera – yet. This is planned for the next stage of development and testing.

Researchers continue development and testing of the wide-view implant with 98 electrodes and the high acuity implant with 1024 electrodes. Patient tests are planned for these devices in due course.

About Bionic Vision Australia

Bionic Vision Australia is a national consortium of researchers from the Bionics Institute, Centre for Eye Research Australia, NICTA, the University of Melbourne and the University of New South Wales.
The National Vision Research Institute, the Royal Victorian Eye and Ear Hospital and the University of Western Sydney are project partners.

The project brings together a cross-disciplinary group of world-leading experts in the fields of ophthalmology, biomedical engineering, electrical engineering and materials science, neuroscience, vision science, psychophysics, wireless integrated-circuit design, and surgical, preclinical and clinical practice.

This research is funded by a $42 million grant over four years from the Australian Research Council (ARC) through its Special Research Initiative (SRI) in Bionic Vision Science and Technology.

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School Aged Vision – Ages 8-16

From the American Optometric Association (www.aoa.org)

School-aged Vision:
6 to 18 Years of Age

A child needs many abilities to succeed in school. Good vision is a key. It has been estimated that as much as 80% of the learning a child does occurs through his or her eyes. Reading, writing, chalkboard work, and using computers are among the visual tasks students perform daily. A child’s eyes are constantly in use in the classroom and at play. When his or her vision is not functioning properly, education and participation in sports can suffer.

As children progress in school, they face increasing demands on their visual abilities.
The school years are a very important time in every child’s life. All parents want to see their children do well in school and most parents do all they can to provide them with the best educational opportunities. But too often one important learning tool may be overlooked – a child’s vision.
As children progress in school, they face increasing demands on their visual abilities. The size of print in schoolbooks becomes smaller and the amount of time spent reading and studying increases significantly. Increased class work and homework place significant demands on the child’s eyes. Unfortunately, the visual abilities of some students aren’t performing up to the task.
When certain visual skills have not developed, or are poorly developed, learning is difficult and stressful, and children will typically:
Avoid reading and other near visual work as much as possible.
Attempt to do the work anyway, but with a lowered level of comprehension or efficiency.
Experience discomfort, fatigue and a short attention span.
Some children with learning difficulties exhibit specific behaviors of hyperactivity and distractibility. These children are often labeled as having “Attention Deficit Hyperactivity Disorder” (ADHD). However, undetected and untreated vision problems can elicit some of the very same signs and symptoms commonly attributed to ADHD. Due to these similarities, some children may be mislabeled as having ADHD when, in fact, they have an undetected vision problem.
Because vision may change frequently during the school years, regular eye and vision care is important. The most common vision problem is nearsightedness or myopia. However, some children have other forms of refractive error like farsightedness and astigmatism. In addition, the existence of eye focusing, eye tracking and eye coordination problems may affect school and sports performance.
Eyeglasses or contact lenses may provide the needed correction for many vision problems. However, a program of vision therapy may also be needed to help develop or enhance vision skills.
Vision Skills Needed For School Success

There are many visual skills beyond seeing clearly that team together to support academic success.
Vision is more than just the ability to see clearly, or having 20/20 eyesight. It is also the ability to understand and respond to what is seen. Basic visual skills include the ability to focus the eyes, use both eyes together as a team, and move them effectively. Other visual perceptual skills include:
recognition (the ability to tell the difference between letters like “b” and “d”),
comprehension (to “picture” in our mind what is happening in a story we are reading), and
retention (to be able to remember and recall details of what we read).
Every child needs to have the following vision skills for effective reading and learning:
Visual acuity — the ability to see clearly in the distance for viewing the chalkboard, at an intermediate distance for the computer, and up close for reading a book.
Eye Focusing — the ability to quickly and accurately maintain clear vision as the distance from objects change, such as when looking from the chalkboard to a paper on the desk and back. Eye focusing allows the child to easily maintain clear vision over time like when reading a book or writing a report.
Eye tracking — the ability to keep the eyes on target when looking from one object to another, moving the eyes along a printed page, or following a moving object like a thrown ball.
Eye teaming — the ability to coordinate and use both eyes together when moving the eyes along a printed page, and to be able to judge distances and see depth for class work and sports.
Eye-hand coordination — the ability to use visual information to monitor and direct the hands when drawing a picture or trying to hit a ball.
Visual perception — the ability to organize images on a printed page into letters, words and ideas and to understand and remember what is read.
If any of these visual skills are lacking or not functioning properly, a child will have to work harder. This can lead to headaches, fatigue and other eyestrain problems. Parents and teachers need to be alert for symptoms that may indicate a child has a vision problem.

Signs of Eye and Vision Problems
A child may not tell you that he or she has a vision problem because they may think the way they see is the way everyone sees.
Signs that may indicate a child has vision problem include:
Frequent eye rubbing or blinking
Short attention span
Avoiding reading and other close activities
Frequent headaches
Covering one eye
Tilting the head to one side
Holding reading materials close to the face
An eye turning in or out
Seeing double
Losing place when reading
Difficulty remembering what he or she read

When is a Vision Exam Needed?

Your child should receive an eye examination at least once every two years-more frequently if specific problems or risk factors exist, or if recommended by your eye doctor.
Unfortunately, parents and educators often incorrectly assume that if a child passes a school screening, then there is no vision problem. However, many school vision screenings only test for distance visual acuity. A child who can see 20/20 can still have a vision problem. In reality, the vision skills needed for successful reading and learning are much more complex.
Even if a child passes a vision screening, they should receive a comprehensive optometric examination if:
They show any of the signs or symptoms of a vision problem listed above.
They are not achieving up to their potential.
They are minimally able to achieve, but have to use excessive time and effort to do so.
Vision changes can occur without your child or you noticing them. Therefore, your child should receive an eye examination at least once every two years-more frequently if specific problems or risk factors exist, or if recommended by your eye doctor. The earlier a vision problem is detected and treated, the more likely treatment will be successful. When needed, the doctor can prescribe treatment including eyeglasses, contact lenses or vision therapy to correct any vision problems.

Sports Vision and Eye Protection
Outdoor games and sports are an enjoyable and important part of most children’s lives. Whether playing catch in the back yard or participating in team sports at school, vision plays an important role in how well a child performs.
Specific visual skills needed for sports include:
Clear distance vision
Good depth perception
Wide field of vision
Effective eye-hand coordination
A child who consistently underperforms a certain skill in a sport, such as always hitting the front of the rim in basketball or swinging late at a pitched ball in baseball, may have a vision problem. If visual skills are not adequate, the child may continue to perform poorly. Correction of vision problems with eyeglasses or contact lenses, or a program of eye exercises called vision therapy can correct many vision problems, enhance vision skills, and improve sports vision performance. (Link to Sports Vision)
Eye protection should also be a major concern to all student athletes, especially in certain high-risk sports. Thousands of children suffer sports-related eye injuries each year and nearly all can be prevented by using the proper protective eyewear. That is why it is essential that all children wear appropriate, protective eyewear whenever playing sports. Eye protection should also be worn for other risky activities such as lawn mowing and trimming.
Regular prescription eyeglasses or contact lenses are not a substitute for appropriate, well-fitted protective eyewear. Athletes need to use sports eyewear that is tailored to protect the eyes while playing the specific sport. Your doctor of optometry can recommend specific sports eyewear to provide the level of protection needed.
It is also important for all children to protect their eyes from damage caused by ultraviolet radiation in sunlight. Sunglasses are needed to protect the eyes outdoors and some sport-specific designs may even help improve sports performance.

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