Education

Use this page to learn some simple facts about common eye conditions optometrists see in clinics.

Diabetic Retinopathy

Diabetic retinopathy is a condition that affects the eyes of people with diabetes. It is caused by high levels of blood sugar damaging the small blood vessels in the retina, which can lead to vision loss or blindness if left untreated. In this blog, we will discuss the prevalence, risk factors, stages, and symptoms of diabetic retinopathy in Australia.

Prevalence: Diabetic retinopathy is a common complication of diabetes in Australia. According to Diabetes Australia, approximately one-third of people with diabetes will develop some form of diabetic retinopathy. It is also the leading cause of blindness among working-age adults in Australia.

Risk Factors:

Several factors can increase the risk of developing diabetic retinopathy, including:

Poorly controlled blood sugar levels
High blood pressure
High cholesterol levels
Smoking
Pregnancy
Duration of diabetes

Stages:

Diabetic retinopathy progresses in stages, and each stage is characterized by specific changes in the retina. The stages of diabetic retinopathy are:

Mild Nonproliferative Retinopathy: In this stage, there are small areas of swelling in the blood vessels of the retina. These areas of swelling are called microaneurysms.
Moderate Nonproliferative Retinopathy: In this stage, some of the blood vessels that supply the retina become blocked. This can cause the retina to become deprived of oxygen, leading to the formation of new blood vessels.
Severe Nonproliferative Retinopathy: In this stage, even more blood vessels become blocked, which further deprives the retina of oxygen. This can cause the growth of new blood vessels, which are fragile and can bleed into the vitreous gel of the eye.
Proliferative Retinopathy: In this final and most advanced stage, the growth of new blood vessels can cause scarring, leading to the retina detaching from the back of the eye. This can cause severe vision loss and blindness.

Symptoms:

In the early stages of diabetic retinopathy, there may be no noticeable symptoms.

As the condition progresses, the following symptoms may occur:

Blurred or distorted vision
Reduced color perception
Dark or empty areas in the vision
Floaters in the vision
Difficulty seeing at night

It is important to note that these symptoms can also be caused by other eye conditions, so it is crucial to see an eye doctor for a proper diagnosis.

In conclusion, diabetic retinopathy is a serious condition that can cause vision loss or blindness in people with diabetes. It is essential to control blood sugar levels, blood pressure, and cholesterol to reduce the risk of developing diabetic retinopathy. Regular eye exams with an eye doctor are crucial for early detection and treatment of the disease.

Glaucoma

Glaucoma is a group of eye conditions that can cause damage to the optic nerve and result in vision loss if left untreated.

Nature and Types of Glaucoma:

Glaucoma is generally caused by an increase in intraocular pressure, which can damage the optic nerve and lead to vision loss.

There are two main types of glaucoma:

1. Open-angle glaucoma:

This is the most common type of glaucoma, and it typically develops slowly over time. In open-angle glaucoma, the drainage angle in the eye becomes clogged, causing fluid to build up and increase the pressure inside the eye.

2. Angle-closure glaucoma:

This type of glaucoma is less common, but it can be more sudden and severe. In angle-closure glaucoma, the iris bulges forward and blocks the drainage angle in the eye, causing a sudden increase in intraocular pressure.

Causes of Glaucoma:

The exact cause of glaucoma is not fully understood, but it is thought to be related to a combination of genetic and environmental factors. Other risk factors for glaucoma include age, family history, certain medical conditions such as diabetes and high blood pressure, and the use of certain medications.

Signs and Symptoms of Glaucoma:

In the early stages, glaucoma may not cause any noticeable symptoms. However, as the condition progresses, it can cause gradual loss of peripheral vision, leading to tunnel vision. Other symptoms of glaucoma can include blurred vision, halos around lights, eye pain, and redness.

Treatment of Glaucoma:

The goal of glaucoma treatment is to reduce intraocular pressure and prevent further damage to the optic nerve.
Treatment options may include:

Eye drops: these can help to lower intraocular pressure by either reducing the amount of fluid produced in the eye or increasing the amount of fluid drained.
Laser surgery: this type of surgery can help to improve the drainage of fluid from the eye and reduce intraocular pressure.
Traditional surgery: this involves creating a new drainage channel in the eye to help reduce intraocular pressure.

Prognosis of Glaucoma:

If left untreated, glaucoma can cause permanent vision loss. However, with early detection and appropriate treatment, most people with glaucoma are able to maintain their vision and prevent further damage to the optic nerve.

In conclusion, glaucoma is a group of eye conditions that can cause damage to the optic nerve and lead to vision loss if left untreated. If you are experiencing any symptoms of glaucoma or have a family history of the condition, it's important to see an eye care professional for a comprehensive eye exam and appropriate treatment.

Cataract

Cataract is the second leading cause of vision impairment worldwide. Cataract is a clouding of the normally clear lens that is found within the eye. This is usually a gradual age-related change but can sometimes occur congenitally or acutely due to systemic disease or ocular trauma. Most cataracts will develop slowly over time and can eventually impact your vision.

Looking through a lens with cataract present can cause symptoms of:

Cloudy, blurred, or dim vision
Increased sensitivity to light and glare
Seeing haloes around lights (which can interfere with driving at night)
Needing brighter lights when reading and doing close work
Fading or yellowing of colours
Double vision in one eye

At the earlier stages, the presence of cataract can cause a person’s prescription to change, so stronger lighting and spectacles can help them deal with the symptoms. Eventually, cataract surgery is required to remove the lens in the eye and replace it with a clear synthetic lens. Once a person’s vision falls below 6/12 they will be eligible for cataract surgery through the public system which is free but the wait time is usually around 1 year. If they want the surgery sooner they can go private which can cost around $3-4 thousand per eye. If cataracts are left untreated it can cause vision loss and blindness.

In the National Eye Health Survey, cataract accounted for 20% of vision loss in Indigenous adults compared to 13% of vision loss in non-Indigenous adults. There was also a gap in the treatment of cataract between Indigenous and non-Indigenous Australians in terms of cataract surgery coverage (59% vs 88%), cataract surgery rate (7,614 per 1,000,000 vs 8,507 per 1,000,000), and median surgery wait time (152 vs 93 days).

Age Related Macula Degeneration

Age related macular degeneration, or AMD, as the name suggests is a condition in which the macula is affected with increasing age. AMD can only be diagnosed after age 55 and the strongest modifiable risk factor of the condition is smoking, increasing the risk of developing AMD by 4 times! Luckily, studies have shown that after 20 years of smoking cessation, individuals are at the same risk of developing AMD as a non-smoker! Other ways to prevent the condition is by following a healthy active lifestyle and a diet rich in leafy greens, such as kale and spinach, and omega-3’s.

Pathogenesis & Outcomes

Normally, the retina (the multi-layered thin tissue lining the inside of the eye), develops deposits of lipid in between its layers, but in AMD these deposits are much larger (called drusen), blocking the light capturing cells (photoreceptors) in your eye from its nutrients and thus die (atrophy). This causes the condition of atrophic/geographic AMD, or historically known as ‘dry-AMD’. Another form of AMD causes the growth of thin blood vessels (angiogenesis or more specifically, neovascularization) to supply the retinal tissue in the eye. Whilst angiogenesis is usually a good thing, these blood vessels have poor infrastructure and they cause leakage of its contents creating a bloody mess! This is known as neovascular AMD or classically, ‘wet-AMD’.

Consequences of AMD can result in poor central vision leaving a blank spot (scotoma) or blurriness. This results in poor detail and facial recognition detaching individuals from recognising their loved ones, street signs or reading their favourite books. Advanced forms of AMD will result in patients suffering from low vision and depending on low vision aids which can be complicated and expensive.

Can you treat AMD?

Treatments for neovascular AMD do exist in Australia, however, there are no commercially available treatments for geographic AMD at this time. AMD is an area of research with rapid and exciting developments being introduced including newly FDA-approved drugs overseas, stem cells, bionic eyes and more! Make sure to watch this space as we are faced with an aging population and AMD will be a familiar condition we will all be treating in the near future.

Please note: “dry” and “wet” AMD are terms no longer used in the emerging literature and should now be avoided in optometric jargon due the complexity of AMD and overlapping features of both conditions in the eyes of some individuals. They are simply noted here for familiarity and educational purposes.

Myopia

Myopia (near-sightedness) is a progressive ocular condition where the eye grows too long relative to the eyes ability to focus. Hence they may see objects up close clearly but in the distance the objects will appear blurry.

High Myopia
High myopia is defined as a prescription of over -6.00D or an axial length of over 26.5mm. The stronger the prescription the higher the risk for sight risking changes to occur. As the eye grows all the tissues that make up the eye can be effected. Myopia can increase the risk for the onset of secondary diseases such as cataract and glaucoma. Light-sensitive tissue in the back of the eye called the retina can become thin and be at risk for holes, tears or retinal detachments which can cause the patient's vision to be at risk. Additionally the earlier the onset the more likely they are to progress as they grow. People with high myopia are 5 times more likely to develop retinal detachments in their life time. Therefore myopia prevention and control is important.

Prevention & Treatment
Myopia can be cause by both genetic and environmental factors. This means children with parents or siblings may have a higher risk for developing myopia but may not necessarily do so. We can reduce the chance a child develops myopia by ensuring they spend time outdoors >2hrs/day, taking regular breaks following screen time (20/20/20 rule) and ensuring there is sufficient light within their surroundings. If a child already has myopia we can slow progression by ensuring the child gets regular check ups; myopia control glasses, specialty contact lenses (orthokeratology or dual focus contact) or low- dose atropine drops. Currently research within this field has shown that these treatments have similar efficacy . However selection of treatment may be very dependent and the patient and their family.