Diabetes is a chronic (long term) condition that affects the whole body including the eyes.  Diabetes interferes with the body’s ability to use and store sugar and can be classified as type one or type two.  Type 1 Diabetes is of an earlier onset and requires treatment with insulin immediately as the body cannot produce insulin itself.  Type 2 Diabetes is now more prevalent and generally comes on during adulthood.  Type 2 Diabetes requires lifestyle modification initially, often needs medication but may require insulin as the disease progresses.

Ocular Complications

Small blood vessels throughout the body, including the eye, are affected by diabetes.  The blood vessels can either be damaged or obstructed. 

When ocular blood vessels are damaged, blood and fluid leak into the surrounding retina (i.e. retinal haemorrhage).  Depending on the location and severity of the haemorrhage floaters may appear, vision may reduce dramatically or there may be no symptoms.

Blood vessel obstruction can lead to a number of complications.  The area/s usually supplied by the blocked vessels undergoes reduced blood flow and if this occurs at the macular, central vision is affected.  More issues can occur in response to blood vessel closure if it is widespread as oxygen supply to the retina is reduced overall.  To compensate for this lack of oxygen the eye “grows” new blood vessels (called neovascularisation).  The new vessels are fragile and leaky meaning they bleed into surrounding tissue.  If this goes untreated a cascade of events occurs.  Unchecked bleeding is followed by retinal scarring which can pull the retina away from the back of the eye, a “tractional retinal detachment”.  Another complication can be growth of new fragile blood vessels in the drainage channels of the eye.  This blocks fluid outflow from the eye leading to increased pressure in the eye.  This process is called neovascular glaucoma.

Risk Factors

·         How long you have had diabetes
·         How well the diabetes is controlled
·         Systemic hypertension (high blood pressure)
·         Systemic hyperlipidaemia (high cholesterol, triglycerides)

In decades past it wasn’t uncommon for people to go blind after a lifetime of having diabetes.  Due to major advances in treatment and earlier diagnosis, visual prognosis is much better today. 

Management and Treatment

Good diabetes control, maintaining normal blood pressure, keeping low blood cholesterol and triglyceride levels are extremely important measures to be taking to avoid sight threatening diabetic retinopathy (DR).

At an eye examination you can expect a number of tests to be performed including measurement of vision, prescription and intra-ocular pressure.  Assessment of the anterior (front) of the eye as well as the retina will also be performed.  To get a better view of the health of your eyes your optometrist / ophthalmologist will probably put drops in your eyes to dilate your pupils.  Other tests including retinal photography, OCT (scan of layers in retina), fluorescein angiography (imaging of blood flow through retinal vessels) can be needed. 

The aim of treatment can be to improve vision or stabilize disease progression and prevent further loss of vision.  The three main methods of treating diabetic retinopathy (DR) are laser, intra-vitreal injection and surgery. 

If your optometrist detects any significant diabetic retinopathy they will refer you to an ophthalmologist for further investigation and treatment, as required.

Regular eye exams are important – appropriate screening, follow up examinations and timely treatment can reduce the risk of severe vision loss or blindness by more than 90%.  Ensure you always attend appointments with your optometrist or ophthalmologist in the recommended timeframe.  If you ever experience a reduction in your vision or a sudden onset of floaters or spots in front of your vision see your ophthalmologist or optometrist immediately.

Where is the macula, what does it do?

The macula is in the middle of the retina which is a film lining the inside of the back of the eye.  The retina is sensitive to light and sends electrical signals to the brain when light reaches it.  The macula is essential for sharp, daytime vision including recognising faces, reading, using a computer and seeing colours clearly.

What is macular degeneration (AMD)?

Macular degeneration involves loss of structural integrity at the macula, this leads to deterioration in central vision but peripheral vision is not affected.  Depending on the nature of the changes at the macula it is classified as ‘wet’ or ‘dry’.  Dry AMD involves a build up of waste deposits (drusen), patches of abnormal pigmentation and areas of thinning at the macular.  Typically, dry maculopathy is associated with a gradual loss of central vision.  Wet AMD is the more aggressive form of macular degeneration and is related to fluid at the macula.  A process called “choroidal neovascularisation” is involved, what this means is new blood vessels growing inappropriately just below the retina.  This is a problem as the blood vessels can leak, in doing so they damage the macula and cause a rapid loss of central vision.

What are the risk factors?

The risk of having macular degeneration increases with age and a strong family history.  Another significant risk factor is smoking; in fact you are three to four times more likely to get macular degeneration if you smoke.  Cardio-vascular factors such as diabetes and high blood pressure can also increase risk of AMD.

Symptoms of macular degeneration may include...

o   Increasing difficulty reading
o   Distortion of straight lines i.e. they appear to be wavy
o   Trouble distinguishing faces
o   Black or missing patches in vision

What treatment is available for people with macular degeneration?

To date there is not a cure for macular degeneration but certain steps can be taken to limits it progression.  For prevention of macular degeneration certain lifestyle choices are important, these include not smoking, exercising and having a healthy diet (see ‘nutrition’ below). 

Your eye care specialist may recommend taking a supplement.  It has been shown by long term studies AREDS and AREDS2 (Age-Related Eye Disease Studies) that supplements can be beneficial in cases of early to intermediate AMD.  Supplements haven’t been shown to be useful in advanced macular degeneration or at the most early stages of AMD.   AREDS/2 showed that people who took a regular high dose of specific nutrients showed a reduced risk of disease progression and a 20 – 25% delay in vision loss.  The nutrients shown to be useful were Zinc, Vitamin C, Vitamin E, Omega-3, Selenium and Lutein/Zeaxanthin.  For the benefits these nutrients must be combined according to a certain formula. 

In the case of wet macular degeneration there is treatment available, again it is not a cure.  Wet AMD involves leakage from blood vessels growing under the macula which damages it and can cause rapid vision loss.  A drug that discourages growth of these new, leaky blood vessels is used to treat wet AMD.  Reduction of inappropriate blood vessel growth leads to reduced leakage at the macular and subsequently less damage and preservation of vision.  This medication is administered directly into the eye via injection.

Tips for a healthy macula

o   Get the health of your eyes checked regularly
o   Don’t smoke and avoid being around people smoking
o   Look after your general health including your weight, exercise frequently
o   Nutrition - Eat leafy green vegetables and fresh fruit daily, have fish two to three times a week and have a handful of nuts about once a week.  Avoid excessive fat and oil and choose complex (low GI) carbohydrates.
o   If recommended by  your doctor / optometrist take an appropriate supplement
o   Use an Amsler grid to self-monitor your macula
o   Be sun-smart to avoid getting UV damage to your eyes, especially important while young

Early detection is very important.  If you notice a reduction or any changes in your vision it is important you have your eyes examined.  Detecting macular degeneration early allows steps to be taken that may slow disease progression and prevent vision loss.

How well your child can see is very important to life at school, both academically and socially.  Vision has a crucial role in both learning and play.  Making sure your child can see well helps them to reach their full potential.

Parents and teachers are in an ideal position to detect signs that a child might not be seeing properly.  In many cases children with eye conditions don’t realise their vision is different to what it could be.  In these cases children try to adapt rather than expressing something is wrong.  Here are a few things to look out for:

What signs may indicate a vision problem?

·         One eye turns in/out while the other looking straight
·         Excessive blinking, red or watery eyes
·         Noticeable head tilting
·         Covering or closing one eye, especially while reading
·         Difficulty learning to read
·         Holding a book very close or sitting close to the TV
·         Squinting or straining to see board
·         Trouble recognising faces of friends or family in the distance
·         Headaches, blurred or double vision

When should children have their eyes tested?

·         Before starting school or during prep is ideal
·         At least every 2 years through school, more often in some cases
·         If a parent or teacher has any concerns

If you are worried about a child’s vision it is best to book them in with an optometrist for a comprehensive eye examination.  School screenings are important but don’t replace a thorough check up.  Even if you are not concerned about your child’s vision it is recommended you have their eyes checked regularly.  Consultation with an optometrist throughout childhood allows early detection of eye diseases or visual problems and is a good step towards maintaining good vision.

There are certain measures that can be taken in the home and classroom to maintain good vision and support developing eyes...

A healthy visual environment includes

·         Adequate (bright, even) lighting is important for reading and playing electronic games
·         Computer use limited to a maximum of 2 hrs at a time, may be less depending on child’s age and how their eyes are developing
·         A well lit classroom
·         Encourage outdoor activities (rather than reading) during school lunch break
·         A broad-brimmed hat to reduce amount of UV rays reaching your child’s eyes

UV rays from the sun pose a threat to our eyes all year around and in all weather conditions.  Just like our skin, our eyes can get burnt and develop serious complications in the long term from excessive exposure.  Damage to our eyes also occurs even if it’s not sunny and not the middle of the day.  Most of us are familiar with the dangers of spending too much time in the sun on hot, clear days.  Our eyes can sustain damage from ultra-violet light at other times too:  

How UV rays can reach our eyes

Direct exposure to sunlight
Reflected UV rays from
Water, snow (both significantly increases exposure)
Sand and concrete
Grass increase exposure to a certain extent
Clouds reflect and scatter light also

The angle of the sun to our eyes at the start and end of the day means more UV light can be absorbed by ocular tissue at these times than in the middle of the day.

Five steps to protect your eyes (tips from the optometry association)

1.       Make sure you protect your eyes from UV, even on days you don’t think the sun’s rays may be as damaging e.g. when it’s overcast.

2.       Limit exposure to UV as much as possible

3.       Wear a broad brimmed hat as it can reduce the amount of UV reaching your eyes by 50%

4.       For outdoor sports, sunglasses or UV blocking contact lenses should be considered.
 5.       Always use UV blocking lenses as well as another form of protection e.g. staying in shade or wearing a hat and sunscreen while outdoors.

Even relatively short bursts of exposure to UV can cause sore, red or irritated eyes.  Other conditions that can arise from UV damage include hypersensitivity to light, pterygium, cancer of the eye lids and front surface of the eye, cataracts and macular complications. Ocular damage accumulates over time and it still adds up even if individual episodes aren’t particularly long.

It’s important to be aware that we are all vulnerable to damage from the sun and to protect our eyes from the UV rays it emits.  Make UV protection part of your daily routine, all year round.

What is a cataract? Why do we get them?

Inside our eyes there is a natural lens, this sits just behind the iris, the coloured part of our eye.  When this biological lens of the eye goes hazy it is called a cataract.

 The lens of a young child is very thin and very clear, every day new lens fibres grow and the lens gets bigger.  As the lens increases in size, its flexibility reduces correspondingly.  This reduction in flexibility translates into less capability to change focus; hence, a child being able to see small objects within 10cm while most adults struggle to do this.  As more and more fibres are added to the lens its transparency is no longer maintained.  This is the most common way a cataract is formed.

Cataract is a general term referring to loss of transparency of the lens.  Usually this hazing occurs gradually over time, as outlined above.  Cataracts can be caused or develop earlier than they would naturally due to UV exposure, ocular trauma, disease or medication.   The fibres of the lens are arranged in a very particular way and trauma can upset this arrangement which leads to reduced transparency.  Conditions such as diabetes can cause cataracts to form earlier as can steroid use. 

How can I tell whether I have a cataract?

Cataracts cause a number of symptoms including reduced vision, increased sensitivity to glare, loss of contrast sensitivity and/or a frequently changing spectacle prescription.  An optometrist can diagnose and assess cataracts.  If your cataract/s requires treatment you will be referred to an ophthalmologist.

What can be done?

Often nothing is done when a cataract is first diagnosed, in some cases they are monitored over a number of years.  When vision is no longer adequate to comfortably perform day to day tasks such as reading or driving cataract surgery is considered. 

Cataract surgery includes removing the hazy lens and replacing it with a clear plastic lens.  Cataract surgery is a very safe procedure, in fact it is one of the most successful and commonly performed surgeries in first world countries.

We all recognise the importance of sunlight as well as the adverse affects of overexposure to it.  Exposure to sunlight is crucial for general health, in particular vitamin D synthesis and pineal function regulation (our sleep-wake cycle, circardian rhythm, time perception etc).

To develop and function properly adequate lighting is very important for our eyes.  Children who spend some time outdoors on a regular basis have reduced rates of certain eye conditions, for example short-sightedness.

So, what happens when our eyes get too much sunshine?

The main reason our eyes and skin are damaged from sun exposure is ultra-violet radiation, generally referred to as UV.  UV is emitted from the sun in rays as visible light is but we can’t see it (because our retina can’t detect rays of that “wavelength”).  A number of changes, in the short and long term, can occur to our eyes when they have too much UV exposure. 

Short term effects (that can continue if exposure isn’t reduced) can include painful, red, watery eyes and feeling like there is sand in the eye.  In extreme cases photokeratitis (‘light’ induced inflammation of the cornea) occurs.  Depending on the means of acquisition, photokeratitis can be called welders flash or snow blindness. 

In the long term over exposure to UV is linked to earlier cataract formation, tumours of the eyelid and pterygium development.  There may also be a link between sun damage and macula degeneration – research is continuing in this area.  It is currently thought that sun related damage to the macula may be related to high end visible light, i.e. blue/purple light (the front of the eye absorbs UV meaning it doesn’t get through to the retina).

It has been well established that limiting the amount of damaging UV rays that get to our eyes improves to ocular health.  The most effective way of doing this is with a pair of sunglasses.  Hats are also an excellent mode of UV protection; they shield parts of our face as well as our eyes but don’t adequately protect our eyes from reflected light.  Another sun smart step to take is avoiding extended exposure to direct sunlight between 10 am and 2 pm.

Happy World Sight Day! We would like to thank everyone from around the world who is taking part in the World Sight Day Challenge by making a donation or fundraising - your support is helping to give sight and hope to people in need.

Our Optometrist Hannah McGowan, reached her goal on Sunday of completing a half marathon. We congratulate her on her achievement and Scenic Rim Optometrists thanks patients for their generous support in supporting this wonderful cause.

This is the latest video shared with you to celebrate World Sight Day. You'll meet 3 primary school children who got their first eye exams and glasses in August thanks to a School Screening Project in Tanzania that is funded by Optometry Giving Sight.

With new technology improving both spectacle frames and lenses it is important that you look after your glasses properly.  This will ensure that they remain comfortable and your vision remains clear for a long time.

Glasses should be cleaned regularly.  Every set of glasses you buy from us will come with a microfibre cleaning cloth, a case of your choice and a spray bottle filled with lens cleaner.  Many other optometrists will charge you extra for these things, but we believe that looking after your glasses correctly is important, so we supply them free of charge.

The microfibre cloth is great for cleaning your glasses when you’re out and about.  It may be a good idea to keep this in your glasses case, and if you get small marks like dirt or fingerprints on your glasses during the day this is perfect for polishing the lenses.

Periodically your glasses will also need a good clean.  To wash your glasses, you should use a small amount of hand soap or gentle detergent to clean your lenses and frames with your fingertips.  Once you have washed your glasses rinse them under luke-warm water.  If your water for washing your dishes isn’t too hot, you can also wash your glasses in the dish water before you wash any dishes in it.

If the frames are clean, you can also use the spray cleaner to spray the lenses front and back, dry with a soft tissue and then polish with your microfiber cloth.  NEVER clean your lenses with a tissue if the lenses are dry.  This will put little scratches in the lens and will eventually destroy the lens.  Likewise, cleaning your glasses on a t-shirt or paper towel isn’t a good idea as these methods of cleaning will also eventually destroy the lenses.