Glaucoma

What is Diabetic Retinopathy

I have just heard that one of my relatives who has diabetes has just be diagnosed with a vision problem called Diabetic Retinopathy, so I have done some research and here is a short explanation that may help you or someone you know.

Diabetic retinopathy is a complication of diabetes which affects the tiny blood vessels in the light-sensitive tissue called the retina that lines the back of the eye. The retina detects light and converts it to signals sent through the optic nerve to the brain. Diabetic retinopathy can cause the blood vessels to bleed or leak fluid, thereby distorting vision. Without treatment, diabetic retinopathy can cause loss of vision and blindness.

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Diabetes interferes with the body’s ability to use and store sugar. The disease is characterised by too much sugar in the blood, which can cause damage throughout the body. Low vision is one symptom of diabetes, other symptoms include:

  • increased thirst and hunger
  • weight gain or loss
  • fatigue
  • frequent urination
  • skin infections, and wounds that heal slowly

Diabetic retinopathy affects a large percentage of all patients who have had diabetes for 20 years or more. It is also one the leading causes of blindness for people aged 20 to 64 years.

Often diabetic retinopathy may not be detected until vision loss occurs so people with diabetes should get a comprehensive eye examination when diabetes is first diagnosed and then these tests should be repeated on a regular basis. Early diagnosis and treatment can usually prevent severe vision loss.

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Studies have shown that controlling diabetes can slow the onset and worsening of diabetic retinopathy. People who monitor and maintain a normal glucose level are significantly less likely to develop the disease than those who don’t. Good glucose control also reduces the likelihood of developing other health problems including kidney and nerve diseases. Trials have also shown that controlling blood pressure and cholesterol levels and avoiding tobacco can also reduce the risk of vision loss.

There are several therapies that may be used alone or in combination for treating the disease and reducing vision loss, however they are not a cure for the disease. These treatments are:

  • Laser surgery – the heat from a laser is used to seal or destroy the leaking blood vessels in the retina.
  • Medication – several medications are available to be used in the treatment of diabetic retinopathy. These medications are injected into the eye.
  • Vitrectomy – this treatment involves the use of surgical instruments to remove the damaged blood vessels. Removing this material allows light rays to focus on the retina again.

Vision lost caused by diabetic retinopathy is sometimes irreversible. However, early detection, regular monitoring and treatment can reduce the risk of blindness by a significant amount.

Our goal at EZiD is to assist all people living with low vision by simplifying some of the decisions they have to make every day, for more information about how we can help please use this link.

by John Owens – john@ezidlabels.comhttp://www.ezidlabels.com

What is low vision?

I have read two definitions:

  • “Low vision is the term used to refer to a visual impairment that is not correctable through surgery, pharmaceuticals, glasses or contact lenses. It is often characterised by partial sight, such as blurred vision, blind spots or tunnel vision. Low vision can impact people of all ages, but is primarily associated with older adults.”and,
  • “Low vision is ‘not enough vision to do whatever it is you need to do’, which can vary from person to person”.

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Your vision can deteriorate with age; however, vision loss does not have to be an accepted part of growing old. A yearly eye examination by an optometrist or vision specialist can identify potential vision problems before they occur. In my case a simple trip to the optometrist to organise a new pair of reading glasses revealed the fact I have Age Related Macular Degeneration. I still needed the new reading glasses, and I was given a referral to an eye specialist who is now treating my macular disease.

Because of this early diagnosis the specialist has told me “I will have very useful vision for a long time”. I am now 63 and a bit so ‘a long time’ sounds like very good news to me.
Some of the more common causes of low vision include:

Age Related Macular Degeneration (AMD): AMD is the leading cause of vision loss, for example in the USA it accounts for nearly 50% of all low vision cases. It is caused when the macular breaks down which can cause the loss of central vision, please see this link for more information about AMD.

Glaucoma: is the second major cause of low vision and it can occur without warning. For more info about glaucoma please use this link.

Diabetic Retinopathy: Diabetic retinopathy affects blood vessels in the retina at the back of the eye. It is a major cause of blindness and it is the most common cause of vision loss among people with diabetes.

Cataracts: Most of the eye’s lens is made of water and protein, and the protein is arranged in an exact way to keep the lens clear. As we grow older some of the protein may clump together creating a cataract. Over time, it may grow larger and cloud more of the lens, making it harder to see.

Vision is also an important factor in maintaining balance. Since 2011 In the USA the rate of life-threatening injuries after a fall since has nearly doubled when compared to the previous decade.

It is a shock when you discover your vision loss cannot be reversed, however please remember it can be treated. So, organise the professional help that will provide you with the strategies and treatments to keep you active and safe. Also, why not have a look at the low vision aids we have created to assist in some of your most common daily activities, you will find everything you need here: www.ezidlabels.com.

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by John Owens – john@ezidlabels.comwww.ezidlabels.com

 

The Braille Alphabet

Louis Simon Braille (1809 – 1852) was born in Coupvray, France, the fourth child and only son of Simon-René Braille, a saddle and horse tack maker, and his wife Monique.

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When Braille was three years old, he injured one of his eyes while playing with his father’s leather making tools. This resulted in both his eyes becoming infected, and by the time Braille was five, he was completely blind. Although there were few options for blind children his parents wanted Braille to be educated, first at the local village school then via a scholarship to attend the National Institute for Blind Youth in Paris.

This was the first school of its kind to educate blind students using a combination of oral instruction and raised-print books developed by the school’s founder. Braille did well at his studies and became an accomplished musician. And the crude raised-print books gave Braille the idea that a tactile alphabet would allow blind people to read and write.

In 1821, a retired soldier named Charles Barbier visited the school to share his invention called sonography. This was a complicated code used by soldiers to write and decode messages at night, using a system of twelve raised dots, without having to use a light. The army decided the system was too complicated, however Barbier thought the system might assist blind people.

Braille and some of the other students recognised the possibilities of sonography and over the next three years Braille worked to develop a much simpler system using six dots lined up in two columns of three dots each.

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Braille became an apprentice teacher at the school when he was 19 and in 1837 the school published the first book in braille. However, the school did not adopt the system. Nonetheless, by 1850, when tuberculosis forced Louis Braille to retire from teaching, his six-dot method was on its way to widespread acceptance.

Louis Braille died of his illness on January 6, 1852, in Paris, at the age of 43. Today, in most languages, braille is the standard form of communication used by blind people.

“Access to communication in the widest sense is access to knowledge, and that is vitally important for us if we are not to go on being despised or patronised by condescending sighted people. We do not need pity, nor do we need to be reminded that we are vulnerable. We must be treated as equals – and communication is the way we can bring this about.” Louis Braille 1841.

See the EZiD braille label here.

Who Created The Eye Test Chart?

The eye test chart was designed by Herman Snellen (1834 – 1908) in 1862. Herman was a Dutch ophthalmologist and he developed the chart as an aid to measure an individual’s vision.

Snellen earned his medical degree at Utrecht University in the Netherlands in 1858. He specialised in ophthalmology after completing his degree and in 1877 was appointed a professor of ophthalmology at the University. His research was based on causes of low vision including glaucoma and astigmatism (a fault in the shape of the eye’s lens).

Other versions of eye test charts had been developed previously however these charts were never standardised. They used fonts of different sizes and shapes and did not necessarily provide an accurate assessment of a person’s real vision.

The British Army placed a large order for the Snellen chart in 1863, and from there it quickly became the global standard for almost 100 years. It is also the standard on which all more recent eye test chart systems are based.

Snellens’ innovation was to use specially designed characters, known as optotypes, instead of an existing, standard font. The Snellen optotype was based on a 5 x 5 grid and this grid was used to create a limited character set of 9 – 10 letters. The lines were a standard thickness and letters were all the same shape.

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This allowed the chart to be reproduced easily and provide accurate results wherever it was used.

The Snellen chart normally includes eleven lines of block letters. The first line comprises a single large letter, usually the letter E. Each of the following lines have increasing numbers of letters, each progressively smaller in size.

The Snellen eye test determines the visual acuity (clarity of vision) of an individual based on which is the smallest row of letters they can read.

With the traditional Snellen eye chart, the individual who can read the row of letters fourth from the bottom of the chart at 20 feet has 20/20 vision. The next three lines provide a measurement of 20/15, 20/10 and 20/5 vision. Not many individuals have 20/10 or better however many animals do, especially birds of prey, which may have an acuity of 20/5 or even better.

Testing with the Snellen eye chart helps reveal visual problems and symptoms of other medical conditions. However it is only one component of a complete eye examination.

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Images courtesy Wikipedia

by John Owens – john@ezidlabels.com   – www.ezidlabels.com

What is Glaucoma?

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Glaucoma is a complicated disease in which the optic nerve at the back of the eye is damaged which leads to progressive, irreversible vision loss. Glaucoma is one of the leading causes of blindness.

There are two main types of glaucoma: primary open angle glaucoma and acute angle closure glaucoma.

The most common form is primary open angle glaucoma. This is often associated with an increase in eye pressure. Eye pressure refers to the tissue pressure within the human eye and is typically caused by the continual drainage and production of aqueous humour.

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The aqueous humour is the watery fluid between the cornea and the lens. It maintains the pressure needed to inflate the eye and provides nutrition for the central cornea and lens as they do not have their own blood supply. It circulates from behind the iris into drainage channels between the iris and the cornea. If it cannot drain away correctly, then there can be a fluid build-up leading to a rise in eye pressure and ultimately damage to the optic nerve.

Eye pressure is usually shown as millimetres of mercury (mm Hg). The standard eye pressure should measure less than 21 mm Hg. Ocular hypertension occurs when the eye pressure increases. Vision damage occurs very slowly and the first signs may be the loss of some parts of the visual field, most commonly the peripheral, or side vision.

Acute angle closure glaucoma occurs when the drainage system becomes completely blocked and the fluid pressure rises quickly as more fluid continues to be made. The usual symptoms are sudden and severe eye pain, a red eye and blurred, haloed or decreased vision. The sufferer may feel sick and vomit and it can rapidly lead to blindness in the affected eye if not treated promptly.

Glaucoma can affect young children also; it is called congenital, paediatric or infantile glaucoma. It is usually diagnosed within the first year of life. Symptoms include enlarged eyes, cloudiness of the cornea and sensitivity to light.

Glaucoma can be treated with eye drops, pills, laser surgery, traditional surgery or a combination of these methods. All are intended to decrease eye pressure and, thereby, protect the optic nerve. The goal of any treatment is to prevent loss of vision, as vision loss from glaucoma is irreversible. The good news is that glaucoma can be managed if detected early, and with medical and/or surgical treatment, most people with glaucoma will not lose their sight.

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John Owens – john@ezidlabels.com   www.ezidlabels.com