Primer on Diabetic Retinopathy

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If you pool everyone with diabetes together and form a nation, they would be the third most populous country in the world.

Those with diabetes will normally find that they have increased levels of glucose in their blood. This can lead to nerve and blood vessel damage as well as an increased risk of cancer due to DNA harm.

Although, not everyone with diabetes will experience sight loss, diabetics will have a higher risk of developing certain visual impairments, such as cataracts and glaucoma.

One of the more common ones is diabetic retinopathy.

This is when the increase in blood sugar levels affect blood vessels at the back of the eye. This interferes with how the retina work and can lead to retinal vessels leaking or bleeding.

 

There are 4 main stages of diabetic retinopathy:

1. Background Retinopathy

This is when capillaries in the retina weaken and develop small areas of swelling. This can lead to small amounts of bleeding as well as the leaking of a fluid called exudate. Although this will normally not affect vision, if it is left untreated the condition can become worse and cause the condition to the next stage.

 

2. Non-Proliferative Retinopathy

Here we see more drastic damage to the capillaries in the retina and usually occurs after years of high blood sugar levels. Bleeding and leaking is more prominent and blood vessels are weakened, potentially losing the ability to transport blood which can cause the retina to malform. Eventually, blood vessels may be completely blocked, which will prompt the body to release growth factors to encourage the formation of new vessels.

 

3. Proliferative Retinopathy

By now, new blood vessels have been formed to help supply blood. However, they are weak and are prone to haemorrhaging and leaking. They can also grow on the retinal surface or inside the vitreous gel. When blood or fluid is leaked, this can damage the retina or block vision when inside the vitreous gel. Scarring can also occur and an increase in scar tissue can cause the retina to detach which may lead to serious sight loss.

 

4. Diabetic Maculopathy

The more common cause of serious sight loss, diabetic maculopathy can occur with or without proliferative retinopathy [Pipe, D.M. & Rapley, L.J. (2008). “Abnormal Ocular Conditions: A Handbook for Dispensing Opticians”]. It occurs when haemorrhaging or leaking involves the macular area of the eye and can cause central vision loss.

 

Symptoms of diabetic retinopathy may not occur at the beginning and can start to appear as the condition advances. Typical manifestations include:

  • Blurred vision
  • Dark spots or patches
  • Eye pain or redness
  • Reduction in night vision
  • Sudden sight loss

Treatment for diabetic retinopathy can depend on how far it has progressed. Laser surgery can be done on a localised area to help reduce swelling and seal up blood vessels. For larger affected areas, pan-retinal laser surgery can be used to shrink abnormal blood vessels and inhibit the release of growth factors. Vitrectomies are used to treat severe bleeding into the vitreous gel. Vitreous is removed and replaced with a clear salt solution to maintain the pressure in the eye.

However, these treatment methods are more aimed at preserving sight rather than restoring. As with many diseases, prevention is just as (if not more) important as treatment. Maintaining a manageable blood sugar level is key and this includes exercise, diet, and generally living a healthy lifestyle.

Primer on Mobility Canes

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Mobility canes. Some call them “white canes”. Others prefer the phrase “symbol cane”. Then there are those who use the word “stick” instead.

Whatever the nomenclature, mobility canes are a recognisable representation of sight impairment.

However, due to the various sizes and design they can come in, people may be confused as to what the differences are and if they are meant to convey different meanings.

Fortunately for you, OXSIGHT have a handy little primer to guide you through the varieties and what they represent.

 

Size Matters

The Symbol Cane - These canes are the shortest of all canes and are not meant for physical support. They are carried around to notify others that the individual may have a visual impairment. Often made out of lightweight aluminium, symbol canes are often collapsable into three or four segments so they can be folded up and stored conveniently away.

The Guide Cane - The next size up from symbol canes are guide canes. These are normally held diagonally in front of you body and used for basic protection, like detecting obstacles such as steps or kerbs. Like symbol canes, they are normally collapsable for easy storage. They may require training to use competently.

The Long Cane - The largest size of cane is the long cane. These extend out and are used by those with limited or no vision to feel the layout of the environment. Again they are collapsable, however they are normally made-to-measure to ensure maximum functionality for each individual. Training is required in order to safely operate long canes.

The Support Cane - Shorter and thicker than long canes, the support cane is used as an aid by providing physical support. They may have a handle on one end and are strong enough to support body weight which means that they are often heavier than the other types of canes. The end of a support cane will generally grip the floor to ensure that it does not slip when in use.

 

Just The Tip

Due to their functional nature, tips on the ends of guide, long, and support canes can be customised based on preferences and intended use.

Some tips may hold an advantage indoors, while others may be more suited to rugged terrain. They come in different shapes and sizes, and more may be introduced in the future as cane technology is further optimised.

Here are some of the more common ones:

Pencil Tip - A thin, straight piece of plastic which slightly extends the length of the cane, pencil tips are used in conjunction with the two-point touch technique. They are extremely lightweight so will not stress the wrist as much. However, due to their size, they are prone to being snagged in cracks and other hazards so are not as suitable for rough terrain.

Marshmallow Tip - Imagine a marshmallow on the end of a stick and that’s what you have. Their larger size provides a greater surface area of contact between the tip and the surroundings. This provides more feedback for the user. They will be slightly heavier due to the increase in bulk.

Ball Tip - One more size up is the ball tip. They are great for beginners and are suited to heavy or extended use as they wear down slower. Constant contact techniques are preferred over two-point touch when using ball tips due to their weight potentially straining the wrist. Their size means users will get alot of feedback and they are very suitable for rough terrain.

Roller Tip - These tips can come in different shapes, such as marshmallow, ball, or disk. They are capable of rolling and so making constant contact techniques easier to do as well as minimise the amount of wear the tip takes. They are good for urban environments but may struggle in more unconventional settings.

Flex Tip - Shaped like a bell, the flex tip does exactly that. When sweeping from side to side, the bell end will bounce over uneven surfaces, making it less prone to snagging. It is specifically designed for rough outdoors use.

Rover Free Wheeling Tip - Perhaps the most heavy duty tip, the rover free wheeling tip is a soft rubberised wheel attached to the end of the cane. It is designed to be rolled forwards and backwards and help navigation over really rough terrain.

Bundu Basher Tip - This tip looks like the end of thin hockey stick and was initially designed to aid navigation through the bush in South Africa. It curves up at the end to prevent it from snagging on rough terrain.

 

Once You Go White…

White - The most traditional and widely used colour for mobility canes. Instantly recognisable as an indicator of visual impairment.

Red Stripes - Often seen on top of white coloured canes, these red stripes indicate that the user also has a hearing impairment in addition to their sight loss.

Any other colour - Although non-traditional, it is possible to purchase canes in other colours. While they will not have the immediate effect of informing others of a visual impairment, they enable the user to display their own personality.

Glow in the dark - Mainly for navigation at night, these canes will not only help the user but also those around them as they can indicate where the user is. Usually, these canes do not require batteries as they will charge up in direct sunlight during the day.

Deafblind UK and OXSIGHT work in partnership to give people their sight back

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Original post by Deafblind UK.

National charity, Deafblind UK, has announced a partnership with OXSIGHT, the provider of high-tech glasses that can give people with visual impairments their sight back.

The partnership sees the two organisations working closely together with the common goal of enhancing the lives of people living with sight loss. Steve Conway, CEO of Deafblind UK said: “Losing your sight can be devastating but even more so when your hearing is also impaired, and you are unable to rely on audio communications. That’s why OXSIGHT’s products are even more important to people who are deafblind.”

OXSIGHT glasses expand the field of vision for people with peripheral sight loss caused by conditions such as Glaucoma, Diabetes, Retinitis Pigmentosa, and other degenerative eye diseases. OXSIGHT are leading the way in the development of digital technology and they are building a strong pipeline of products to help those with a whole range of conditions including central vision.

Deafblind UK’s Chairman Bob Nolan uses the glasses. He said: “The moment when I first tried on the OXSIGHT glasses will stay with me for a long time. I was talking with one of my family members and I could only make out her head and shoulders in a dimly lit room. When I put the glasses on I could clearly see not one but five members of my family! When you have less than five degrees of vision as I do, looking through the glasses is nothing short of miraculous.”

Deafblind UK is a national charity supporting people with sight and hearing loss. As part of the partnership, OXSIGHT will hold monthly clinics at Deafblind UK’s office in Peterborough, where those with peripheral sight loss can book an appointment to try a pair of glasses. For every pair of glasses sold as a result of the clinic, OXSIGHT will make a donation to Deafblind UK.

Steve Conway, CEO of Deafblind UK said: “This is a fantastic example of a charity and a technology company coming together with a mutual interest to support people who are deafblind. The success stories that we have heard so far are incredible; people who haven’t seen their partner or children for years can suddenly see the world around them again. This really is life changing technology and I am proud to be a part of it.”

Rammy Arafa from OXSIGHT has been working with Deafblind UK to set up the partnership. He said: “I am delighted to be able to work so closely with Deafblind UK. They work so hard to support people with sight and hearing loss and our product will complement their existing service offering. If, by working together, we can help some of Deafblind UK’s members to see again then it’s a worthwhile venture.”

OXSIGHT clinics will take place at Deafblind UK’s office on: 21st August, 23rd October, 20th November, 18th December, 22nd January, 26th February, 25th March. For anyone interested in booking an appointment at the clinic, please complete an online form at www.oxsight.co.uk/consent. OXSIGHT registered opticians will then review your individual condition and let you know whether you are suitable to try the glasses.

Smoking and Sight Loss

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The act of smoking is normally associated with a trip to the doctor’s and the subsequent discovery of cancerous cells in and around the lung region.

However, amongst the myriad of ailments smoking can cause lies vision loss.

Toxins inhaled into the body through smoking can help contribute to occurrences of vasoconstriction, reduced oxygen availability, and chronic inflammation. In addition, smoking increases the number of oxidative radicals in the body and lowers the level of antioxidants. This results in a ramp up of the body’s aging process.

However, due to the sheer amount of harmful chemicals there are in tobacco, harm is not limited to just internal. Smoke from tobacco contain ash particles and these can physically come in contact with the eye, causing harm.

This means that ocular distress from smoking is not just limited to those that actively take part in it. Bystanders within the smoker’s area of influence may also be subject to some of the harmful effects.

Here are some of the most common eye conditions associated with smoking:

 

Cataracts

Smokers will inhale heavy metals, including cadmium, iron, lead, and copper. These can accumulate in the lens of the eyes and cause damage. Oxidative radicals can also cause changes to the lens structure and composition, contributing to the formation of cataracts, which is a clouding of the lens in the eye.

 

Age-related Macular Degeneration (AMD)

AMD is one of the leading causes of sight loss in the UK and smoking is one of the factors why. Those that smoke can be at increased risk due to the numerous toxins present. Tar from cigarettes can also help the formations of drusens, which are fatty deposits in the retina.

Those who already have signs of AMD may find that the condition progresses faster if they are smokers.

 

Graves’ Ophthalmopathy

Graves’ ophthalmology, also known as thyroid eye disease (TED), occurs mostly amongst individuals with Graves’ disease, an autoimmune disease that impacts the thyroid.

Smoking can affect the thyroid gland and prevent the uptake of iodine as well as negatively impact the sympathetic nervous system which can then affect thyroid function. According to studies, smokers with Graves’ disease are at least twice as like to develop TED, with the probability increasing up to eight times for those that heavily engage in smoking.

Due to treatment methods often involving consumption of iodine, smoking can also reduce the efficacy of therapy, making it even harder to recover from.

 

Dry Eyes

Dry eye is most commonly caused by one or more glands in the lids reducing in function. This can be caused by blockages in those glands which causes more friction on the front surface of the eye. In some cases, the eyes will water profusely because the eye believes it is dry so it secretes more fluid. However, because there are three layers to the tears, if one is not functioning properly then the tear may not be able to relieve the dryness.

Although not as serious as the other conditions listed, dry eyes can be made worse due to smokers experiencing reduced tear production. If left untreated, this can lead to a variety of complications with the individual’s cornea.

Primer on Stroke-related Vision Loss

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You push open the heavy oak doors of the pub and are instantly hit with a barrage of jovial sounds mixed with the scent of a strong alcohol and sweat cocktail.

Scanning round the establishment, you quickly locate your friends and make your way to the empty seat left, you presume, for you.

And then the drinks start.

After a few rounds or more, you start to notice a numbing sensation on the left side of your body. Your friends comment on how your left eye and mouth are drooping. You try to say that something seems wrong, but it all sounds garbled and nonsensical.

At first, you blame it on the alcohol, but then you realise that you can no longer move your left arm. You start panicking.

You’re having a stroke.

The next thing you remember is waking up in a hospital room. It’s dark and you’re alone.

You mentally check over yourself. Arm works. Face seems to be as expressive as ever. Mental calculations are tough, but you were never good at them anyway. Words sound clear enough.

Footsteps gradually increase in volume and you realise that they are coming to you.

You quickly close your eyes as light suddenly invade your eyes. As you become accustomed, you tentatively open your eyes.

But you can only see half of what you would normally see.

One side of your vision is gone.

 

Strokes occur when a part of the brain is deprived of oxygen. It is life threatening and can leave the victim/survivor with a series of conditions, ranging from mental to physical to cognitive.

There are also various visual problems that can arise. Here are some of the most common stroke related sight loss conditions.

 

Visual field loss

This is when parts of vision is lost. Hemianopia is when one half of vision is gone so those with the condition will only be able to see either the left or right half of what they are looking at.

It is also possible to lose central vision, which may mean that it is not possible to directly look at something.

 

Eye movement complications

Strokes can affect a victim’s control over their eyes. This may mean that the eyes are unable to coordinate with each other, which can cause diplopia (double vision).

Some may also experience an uncontrollable wobble of the eyes (nystagmus) which can result in reading difficulties.

 

Trouble with visual processing

Strokes can disrupt the way information is passed from the eyes to the brain and how that is processed. This miscommunication can often result in visual neglect, which is when something that is seen is not processed and therefore does not register with the individual. You may find that these individuals will unintentionally ignore people or objects because their brain has not interpreted the data sent by the eyes.

The other extreme is also possible as many will experience hallucinations caused by processing errors by the brain, giving them images of things that aren’t actually there.

 

Due to the wide range of visual conditions suffered by stroke victims, there is no one-fix-for-all. Treatment can help the victim cope and adapt to their vision loss, and can come in the form of rehabilitation, accessories, or smart glasses, depending on the exact nature of their condition.

Some people will find that their vision improves for up to 6 months after their stroke. But again this depends on how well their brain heals after the initial damage.

OXSIGHT Co-founder Stephen Hicks on the HealthRedesigned podcast

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OXSIGHT co-founder and head of innovation Stephen Hicks was invited onto the HealthRedesigned podcast to talk to Matt from Hanno.

They discuss neuroscience, delve into augmented reality, and how OXSIGHT is helping those with vision problems.

This is a rare insight in the more technical side of OXSIGHT and what we are working on and the challenges that need to overcome to help as many people as possible.

Listen below and enjoy!

 

 

Primer on Glaucoma

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Glaucoma can trace its roots to Ancient Greece and is derived from the word Glaux which means owl. Ancient Greeks had a propensity to name diseases after animal due to their belief that this animal would then help the patient combat the disease.

And so it is the owl that plays a central role in combating Glaucoma.

Ancient Greek gem showing an owl taking centre stage in the fight against eye disease. [lww.com]

Glaucoma is an eye condition where the optic nerve is damaged. This is normally caused through buildup of fluid in the eye which increases pressure. The pressure can injure or exploit a pre-existing weakness in the optic nerve.

The effects of this damage may not be noticeable at first due to it normally developing over many years and primarily affecting peripheral vision. Because of this it is advised to take regular eye tests as this is usually how glaucoma is detected.

Due to the variable nature of the cause, there are five main types of glaucoma, with most characterised by patchy blind spots in peripheral or central vision of both eyes.

  • Primary open angle glaucoma is the most common type and is characterised by slow damage to the optic and changes to eyesight.
  • Closed angle glaucoma occurs when eye pressure rises suddenly and can be very painful.
  • Normal tension glaucoma is when the pressure is within the normal range but damage to the optic nerve still happens.
  • Secondary glaucoma is a result of the presence of another eye condition, an injury to the eye, or certain medication or treatments.
  • It is also possible to be born with an improper drainage system in the eye causing congenital glaucoma.

Currently, there is no cure to restore the vision of someone with glaucoma. However, it is possible to stop or slow the degradation of vision and stave away permanent sight loss by controlling the level of pressure in the eyes.

Eyedrops are the most common form of treatment with many people using them daily for many years. For some, it may be necessary to have laser eye treatment or surgery to help control the pressure.

Recent developments have seen specialty glasses produced which can condense a wider field of view and display it in a patient’s more narrow field of view, effectively replacing part of their lost vision. More and more people are finding these smart glasses useful in their daily lives and the future points towards more advanced developments and further innovation in this field.