Common Eye Conditions

A cataract is the cloudiness of the lens inside the eye. Light that enters the eye no longer travels a straight path and becomes scattered. Images are not focused properly at the back of the eye, resulting in a loss of vision.

Symptoms of a cataract can include gradual reduced vision, glare, and sensitivity to bright lights and haloes around lights (particularly at night).

When a cataract has formed, surgery is required to remove the lens and replace it with an artificial lens called an intraocular lens (IOL).

Cataracts are part of the normal ageing process. By the age of 60, approximately half of all adults will develop a cataract and by the age of 70 most people would have a cataract begin to form inside the eye.

Trauma to the eye, diabetes, certain medications, and excessive ultraviolet light exposure can all cause a cataract to develop earlier.

A pterygium is a benign wedge-shaped growth of tissue over the white of the eye (called the conjunctiva). It will usually begin to grow near the inner corner of the eye, often extending out onto the clear central portion of the eye (called the cornea).

As a pterygium grows and increases in size, it can cause the eye to become very red due to the new blood vessels that grow within the pterygium and begin to distort the shape of the front of the eye and cause blurred or obstructed vision in the eye. It may also cause symptoms of discomfort such as burning, tearing or grittiness in the eye. If this happens then the pterygium can be surgically removed.

The exact causes of a pterygium are not known, but they are more likely to develop in people who live in hot climates and are exposed to large periods of time out in the sun.

Glaucoma is the leading cause of irreversible blindness worldwide. Over 300 000 Australians have glaucoma and 50% of Australians with glaucoma are undiagnosed. First degree relatives of those with glaucoma have a ten-fold increased risk of developing the disease.

Glaucoma is a group of diseases that cause damage to the optic nerve. The optic nerve is located at the back of the eye and its job is to transmit information from the eye to the visual centres of the brain.

In most people, this damage is due to increase pressure inside the eye. This occurs when there is a blockage in the flow of aqueous (the fluid circulating within the eye, which nourishes the eye and keeps it firm). In other people the damage may be caused by poor blood supply to the optic nerve, or a weakness in the structure of the nerve and/or a problem in the health of the nerve fibres themselves. Loss of vision due to glaucoma is gradual and not associated with any pain or warning signs. A considerable amount of peripheral vision may be lost before a person can become aware of having the disease. This is why glaucoma is often referred to as “the sneak thief of sight”.

Diagnosing Glaucoma

A comprehensive eye examination is required to detect glaucoma and includes the following tests:

• Measurement of the pressure within the eye
• Examination of the optic nerve using a special instrument called an ophthalmoscope to assess its colour and appearance, which can indicate whether or not damage from glaucoma is present and how extensive it is
• Assessing the drainage structures within the eye where the aqueous flows through
• Taking a measurement of the thickness of the cornea (the clear protective layer at the front of the eye)
• A visual field assessment using a computerised machine to check peripheral vision
• Imaging of the optic nerve using specialised ophthalmic equipment to analyse its health

When should I start being examined for Glaucoma?

You need to be checked for glaucoma from the age of 35 if you have:

• High intraocular pressure readings
• Family history of glaucoma
• Diabetes
• Migraines
• Myopia (short-sightedness)
• A history of prolonged use of corticosteroid medications
• High blood pressure
• A previous injury to your eye

If you are of African or Asian descent, then you should be checked from the age of 40.

For all other people, it is recommended that glaucoma checks commence from the age of 50.

If you fall into any of the above categories, you should see your General Practitioner for a referral to an Ophthalmologist.

Glaucoma Treatment

There is no cure for glaucoma, however, any further loss of sight can be either prevented or slowed down by the following means:

• Eye drops – these are the most common treatment for glaucoma and are to be used indefinitely
• Laser – this form of treatment may be used initially when a person is diagnosed with glaucoma, or when eye drops are first trialled and do not work effectively
• Surgery – this is performed when drops and laser do not halt the progression of glaucoma

We can discuss these options with you in more depth if required. Please contact us to make an appointment.

Diabetic retinopathy is an eye condition caused by diabetes, where the small blood vessels in the retina become damaged. The retinal blood vessels swell and leak fluid or blood, which in turn can lead to vision. 44% of people who are diagnosed with diabetes will develop diabetic retinopathy at some stage of their lives. It is the leading cause of blindness in working-age Australians.

Diabetic Retinopathy Symptoms

The symptoms of diabetic retinopathy are:

• Blurred vision that makes it difficult to read, watch television, or see people’s faces
• Sudden changes in vision
• Seeing floaters or spots in your vision
• Sensitivity to glare
• Difficulty seeing at night
• Double vision

Who is at risk of developing diabetic retinopathy?

You are at risk of developing diabetic retinopathy if you:

• Have a long history of diabetes
• Have poorly managed diabetes (high blood glucose levels)
• Have diabetes with high blood pressure
• Have diabetes with high cholesterol
• Have diabetes and smoke

If you fall into any of the above categories, you should see your General Practitioner for a referral to an Ophthalmologist.

There are two types of diabetic retinopathy; non-proliferative and proliferative.

Non-Proliferative Diabetic Retinopathy

This is the earliest stage of diabetic retinopathy, where damaged retinal blood vessels develop tiny weak areas call microaneurysms. Over time, these microaneurysms can rupture and leak causing haemorrhaging (bleeding) into the retina. Fluid, fats, and protein from the blood stream can also leak into the retina (these are called exudates). Eventually poor blood circulation of the retina can also result in death of nerve cells (ischaemia). The combination of these processes can lead to permanent visual loss. Abnormal blood vessels can grow and also cause haemorrhaging or leakage of fats and proteins, which form deposits. If fluid collects in the area of central vision diminished or blurred vision will result. However, if it occurs in the outer edges of the retina no symptoms may be noticed.

Proliferative Diabetic Retinopathy

This is the more advanced stage of diabetic retinopathy. The retina may produce substances that promote the growth of new, abnormal blood vessels across the retina and into the clear vitreous gel of the eye, as a result of ischaema (a process known as neovascularisation). These new, abnormal blood vessels are very weak and may bleed into the vitreous and cause the vision to become cloudy, or result in scar tissue that may pull on the retina. Connective tissue growing along with the blood vessels may contract and pull on the retina, causing a retinal detachment. These new blood vessels are, however, fragile and tend to bleed into the vitreous or result in scar tissues that pull on the retina and cause a very serious condition called tractional retinal detachment.

If diabetic retinopathy is diagnosed you may need to undergo further investigations, such as fluorescein angiography or an OCT scan to evaluate the severity of the condition. The purpose of these further investigations is to identify areas of macular oedema, ischaemia, and neovascularisation, so an appropriate treatment can be applied. A B-scan ultrasound may need to be performed also, if the vitreous haemorrhage is very dense and the retina cannot be examined properly.

It is highly important that anyone diagnosed with diabetes has their eyes checked. Vision can still appear normal in quite advanced diabetic retinopathy so, by the time any changes in vision are observed, irreversible damage to the eye may have occurred.

Diabetes Australia recommends that people diagnosed with diabetes should have their eyes check when diabetes is first diagnosed and then regularly checked at least every two years, or as recommended by their Ophthalmologist.

Age related macular degeneration is an eye disease affecting people aged 50 and older that causes a progressive and painless loss, blur, or distortion of central vision. This is caused by a deterioration of the macula – the small, central area of the retina that is used for straight ahead vision. ARMD can affect a person’s ability to see fine detail for tasks such a driving, reading, sewing, cooking, and recognising faces. About one in seven Australians over the age of 50 exhibit signs of ARMD. It is the leading cause of legal blindness in Australia and is responsible for 50% off all cases of blindness.

There are two subtypes; Dry ARMD and Wet ARMD

Dry ARMD

Dry ARMD is the most prevalent form of macular degeneration, accounting for 90% of all ARMD cases. It is characterised by the presence of yellow deposits, called drusen, in the macula. As these drusen grow in size and increase in number they may lead to a dimming or distortion of vision that people find most noticeable when they read. In more advanced stages of dry ARMD there is also a thinning of the light-sensitive layer of cells in the macula, leading to atrophy or tissue death. Patients may notice blind spots in the centre of their vision. In the advanced stages, patients lose central vision.

Wet ARMD

Wet ARMD is the most severe form of ARMD, accounting for approximately 10% of all ARMD cases and is characterised by the growth of abnormal blood vessels underneath the macula. These new blood vessels leak blood and fluid into the retina, causing distortion of vision that makes straight lines look wavy, as well as blind spots and loss of central vision. These abnormal blood vessels and their bleeding will eventually form a scar, leading to permanent loss of central vision. If wet ARMD is left untreated, rapid and severe loss of the central vision can occur within a short period of time.

Risk Factors for ARMD

Age is a major risk factor for ARMD for patients over the age of 60. Studies have shown that those who smoke are three to four times more likely to develop macular degeneration and may also develop the disease five to ten years earlier than non-smokers. People with a family history of ARMD are at higher risk. At last count, researchers had identified nearly 20 genes that can affect the risk of developing ARMD. There is a 50% chance of developing ARMD if there is a direct family history.

If you fall into any of the above categories, you should see your General Practitioner for a referral to an Ophthalmologist.

Treatment for ARMD

There is currently no cure for ARMD, however, studies have shown that diet and lifestyle changes, including the use of an appropriate supplement, may slow down the progression of the disease. Any changes to diet or lifestyle should be undertaken in consultation with a doctor. Treatment varies depending on the type of ARMD and individual characteristics of the condition. Treatment is directed at maintaining useful central vision for as long as possible.

Treatment for Dry ARMD

There are currently no medical treatments available for dry ARMD, however, there is a substantial amount of research being conducted to find a treatment.

Treatment for Wet ARMD

Injections

The wet form of ARMD may be treated with an injection of a drug directly into the eye. The drug helps to stop the abnormal growth of blood vessels. The majority of people treated are able to maintain their vision and some people may even experience an improvement in their vision.

The treatment regimen begins with monthly injections for three months. Then, to maintain control of the disease, injections are typically continued on an indefinite basis. The interval between these ongoing injections is determined on an individualised basis by the Ophthalmologist in consultation with the patient.

Laser Treatment

Laser treatment seals and destroys the leaking blood vessels. It may be recommended if the blood vessels are located away from the centre of the macula, as any laser performed will not only destroy the leaky blood vessels but also any retina adjacent to these abnormal blood vessels.

Photodynamic Therapy (PDT)

Photodynamic therapy is a light-sensitive drug that is injected into the veins in the arm and a specially designed cool laser is used to close off abnormal blood vessels in the retina. This treatment is often used in combination with injections to the eye and is suitable only for specific subtypes of wet ARMD.

We can discuss these options with you in more depth if required. Please contact us to make an appointment.