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retinal vein occlusion treatment melbourne

Retinal Vein Occlusion Treatment — All You Need To Know

June 8, 2023/0 Comments/in Retinal Surgery /by Armadale Eye Clinic Team

A retinal vein occlusion is a medical term to describe a blockage of one of the blood vessels of the retina. Being such a metabolically active tissue, the retina requires a high oxygen and energy demand. This makes retinal vein occlusions a potential medical emergency with a risk of permanent vision loss. Keep reading to learn more about treatment for this vision-threatening retinal condition.

What is a Retinal Vein Occlusion?

Any occlusion (blockage) of a retinal vein is called retinal vein occlusion. This can occur in the main vein of the retina, which is then known as a central retinal vein occlusion (CRVO), or in one of the smaller offshoot retinal veins, which is then termed a branch retinal vein occlusion (BRVO). There are also even smaller branches of the retinal vein network known as retinal capillaries.

The retinal vein network is responsible for taking away deoxygenated blood from the retina back to the heart and lungs to be replenished with oxygen. Retinal arteries are the blood vessels that carry blood back from the lungs to the retina, restocked with vital oxygen and nutrients.

Causes of Retinal Vein Occlusion

The causes of retinal vein occlusions tend to be due to a blood clot becoming trapped in the blood vessel. This blockage stops the flow of blood throughout the network of retinal blood vessels.

Central Retinal Vein Occlusion

In a central retinal vein occlusion, the location of this blood clot is often around where the optic nerve enters the eye. In some cases, the clot can become lodged within the retinal vein after it’s exited the eyeball.

Branch Retinal Vein Occlusion

During a branch retinal vein occlusion (BRVO), a clot is more likely to form at the point where the retinal vein crosses over a retinal artery.

Occlusion of branch retinal veins is up to seven times more frequent compared to blockages of the central retinal vein.

Do Retinal Vein Occlusions Cause Vision Loss?

Vision loss from a retinal vein occlusion, whether in the central or branch vessel, is due to one or both of two possible complications.

Macular Oedema

Macular oedema (also spelled as macular edema) refers to swelling of the macula area. The macula is the part of the retina you use for central vision. Damage to these nerve cells from macular oedema can result in significant vision loss. Because we use our central vision for so many crucial tasks, such as recognising faces, reading, and writing, vision impairment from macular oedema can be particularly devastating.

Retinal Ischaemia

This is the medical term for lack of oxygen to the retinal nerve cells, which can affect a wide area of the retina or a small area, depending on the location of the retinal vein occlusion.

If the retina is experiencing low oxygen, it often responds by growing new blood vessels. The problem is that these abnormal blood vessels can be subject to fluid leakage, which contributes to macular edema. The other complication is if these new blood vessels grow into the structures at the front of the eye, it can induce elevated eye pressure and subsequent damage to the optic nerve in a disease called neovascular glaucoma.

Retinal Vein Occlusion Treatment

Timely treatment can help to maintain vision; however, despite treatment, it is possible to experience permanent damage and some degree of long-term vision loss.

The decision on how best to treat a vein occlusion is based on the location and size of the blockage. Your eye doctor will perform a thorough assessment of your retina and any other relevant health problems. Tests can include imaging scans such as optical coherence tomography, which is useful for visualising the location and degree of macular swelling, and another test called fluorescein angiography, which shows a map of the retinal blood vessels, including areas of leaking fluid or retinal ischaemia.

Intravitreal Injections

The first-line treatment for macular edema caused by a retinal vein occlusion is with a therapy called anti-VEGF injections. Anti-VEGF therapy involves intravitreal injection (that is, injected directly into the eyeball) of a drug known as anti-vascular endothelial growth factor, which inhibits the growth of abnormal new blood vessels.

Anti-VEGF injections are also used to treat the swelling of the macula in macular edema. These injections will often need to be repeated monthly for at least a few months. If required, you may need further injections at regular intervals to maintain the effects of the therapy.

Laser Treatment

In some cases, laser treatment will be the most appropriate for treating the complications of a retinal vein occlusion.

Focal Laser Therapy

Focal laser therapy involves the use of a laser tool to seal off blood vessels close to the macula to prevent fluid leaking. Essentially, the treated blood vessels are cauterised closed.

Laser Surgery

Laser surgery can be used if new blood vessels are beginning to develop in the retina due to ischaemia. Using a laser to create tiny burns in the retina reduces its oxygen demand and minimises the trigger to grow extra vessels.

Risk Factors and Prevention

Although it’s not possible to make yourself immune to ever experiencing a retinal vein occlusion, you can minimise your likelihood by understanding and managing your risk factors.

The risk factors for retinal vein occlusion are similar to those for other cardiovascular diseases, such as heart attack and stroke. They include:

Older age
High blood pressure (hypertension)
High cholesterol
Diabetes
Being overweight
Smoking

Though you can’t do much about ageing, taking steps to control your other risk factors can help to reduce your risk of vision loss due to retinal vein occlusion.

There is also some suggestion that the contraceptive pill can contribute to an elevated risk of retinal vein occlusion, though this has been rarely reported. Speak to your doctor if you have any concerns.

Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.

References

Retinal Vein Occlusion
https://www.college-optometrists.org/clinical-guidance/clinical-management-guidelines/retinal-vein-occlusion

Retinal vein occlusion
https://www.mdfoundation.com.au/about-macular-disease/other-macular-conditions/retinal-vein-occlusion/

What is Retinal Vein Occlusion
https://www.webmd.com/eye-health/retinal-vein-occlusion

how serious is retinal vein occlusion melbourne

How Serious is Retinal Vein Occlusion? Diagnosis and Treatment

May 27, 2023/0 Comments/in Retinal Surgery /by The Armadale Eye Clinic Team

The retina is the light-sensitive tissue lining the back of the eyeball. Because it’s constantly working, it requires a rich network of blood vessels to bring nutrients and oxygen to its tissues as well as carry away metabolic waste material. A disruption to this blood flow can have consequences ranging from being entirely asymptomatic to a potentially serious threat involving permanent damage and vision loss, depending on the affected blood vessels.

Blood Vessels of the Retina

Freshly oxygenated blood is carried into the eye via the central retinal artery, which splits into smaller branch arteries and then even smaller retinal capillaries.

Once the blood has delivered its oxygen to the retina, the deoxygenated blood is removed from the eye via the network of retinal veins.

From branch retinal veins, blood flows into the main retinal vein, known as the central retinal vein, and eventually back to the heart and lungs.

A blocked vein can occur in either a branch retinal vein (branch retinal vein occlusion, BRVO) or the central retinal vein (central retinal vein occlusion, CRVO).

Depending on where the retinal vein occlusion occurs, you may notice a sudden and profound loss of your central vision or, alternatively, no discernable change to your vision at all.

Central Retinal Vein Occlusions

In most cases, a central retinal vein occlusion occurs when blood flow is blocked in the central retinal vein due to a blood clot. A central retinal vein occlusion can occur around the same point where the optic nerve enters the eye or even at a point outside of the eyeball after the central retinal vein has exited the eye. The presence of blood clots prevents blood from flowing out through the retinal vein and backs up blood circulation through the entire network of retinal blood vessels. This results in bleeding into the retina and deprives areas of the retina of fresh oxygen.

Branch Retinal Vein Occlusions

Branch retinal vein occlusions are up to seven times more frequent compared to central retinal vein occlusions. Like a central retinal vein occlusion, a branch retinal vein occlusion is due to a blood clot resulting in poor blood flow through that particular retinal vein, resulting in haemorrhaging and poor oxygen supply. Most instances of a branch retinal vein occlusion occur at the point where the retinal vein crosses with a retinal artery.

How Is Vision Affected During a Retinal Vein Occlusion?

The main threat to the vision from a retinal vein occlusion, whether central or branch vein, is swelling of the macula, known as macular oedema, or the formation of abnormal blood vessels due to low oxygen in the retina. Vision loss from a retinal vascular occlusion is not associated with eye pain or discomfort. Instead, you’re more likely to experience a sudden painless blurring of your central vision. A retinal vascular occlusion does not result in complete blindness even in the event of macular oedema, as there will be other parts of your vision that remain intact.

Macular oedema is the most common cause of vision loss following retinal vessel occlusion. The macula is the part of the retina responsible for central vision, which is why damage and swelling of this area are significant. Macular oedema can lead to permanent central vision loss, even despite immediate or urgent treatment. Instances of macular oedema can develop even months after the original retinal vein occlusion event.

Retinal ischaemia refers to a lack of oxygen. The retina responds by creating new blood vessels, which are fragile and leaky. This, in turn, can contribute to macular oedema and result in poor vision. If these abnormal blood vessels form around the iris and fluid drainage channels of the eye, elevated eye pressure and a type of vision-threatening eye disease called neovascular glaucoma can become a risk.

The majority of retinal vein occlusions occur in just one eye. However, the risk of developing a retinal vein occlusion in the other eye will be elevated over subsequent years.

Risk Factors for Retinal Vein Occlusion

The reasons why some people develop blood clots in a retinal vein are not fully understood, though several risk factors for retinal vein occlusions have been identified. Having any of the risk factors doesn’t mean you’re guaranteed to have a retinal vascular occlusion, while not having any risk factors doesn’t mean you’re immune from it.

Risk factors for a retinal vein occlusion can include:

High blood pressure
Systemic conditions that affect blood flow, such as hardening of the arteries (atherosclerosis), blood clots elsewhere in the body, and heart disease
Smoking
High cholesterol
Older age
Diabetes

Diagnosis of a Retinal Vein Occlusion

Both optometrists and ophthalmologists are able to diagnose a retinal vein occlusion, though only ophthalmologists (eye doctors) are qualified to treat it.

Your eye care professional will be able to diagnose a retinal vein occlusion by viewing the retina. This may require a dilated eye exam with the instillation of eye drops that widen the pupil for a better view. Retinal imaging with a specialised camera can also be useful for visualising the retina and any areas of retinal vascular occlusion and haemorrhaging.

Other imaging techniques, such as optical coherence tomography (OCT), are often used, especially for macular edema. This gives a better view of the macula and can be used to monitor the degree of swelling.

Your optometrist or ophthalmologist will also monitor your visual acuity, which is typically measured by reading black letters of decreasing size against a white chart. Other relevant tests can include checking for abnormal blood vessels in the drainage structure of the eye and measuring eye pressure.

How is Retinal Vein Occlusion Treated?

Treatment for macular oedema is with eye injections of a drug known as anti-VEGF therapy. This treatment will usually require monthly injections for at least a few months until the swelling has resolved. This medication can also be used for treating abnormal new blood vessels, reducing your risk of neovascular glaucoma.

In some cases, laser therapy can also be useful for sealing off the leakage from these new blood vessels.

Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.

References

Retinal Vein Occlusion.
https://www.college-optometrists.org/clinical-guidance/clinical-management-guidelines/retinal-vein-occlusion

Retinal vein occlusion.
https://www.mdfoundation.com.au/about-macular-disease/other-macular-conditions/retinal-vein-occlusion/

Macular Degeneration Causes — Everything You Need To Know

October 31, 2022/0 Comments/in Retinal Surgery /by The Armadale Eye Clinic Team

The macula is an anatomical part of the retina. The retina is the tissue lining the back of the eye, comprised of millions of photoreceptors that sense light. The macula is what is responsible for your central vision. We rely on our central vision for a lot of things – reading, writing, watching TV, recognising faces, painting, sewing, identifying colours… You name it. Basically, whenever you look at something, you’re turning your macula to receive that fine detail. So, what happens when macular degeneration sets in? Keep reading to find out about macular degeneration causes and symptoms.

What is Macular Degeneration?

The term macular degeneration typically refers to an eye disease of older age. The full name is age-related macular degeneration. As the name suggests, age-related macular degeneration:

Affects older adults; typically, ages over 50 years are considered a risk factor
Results in damage and degeneration of the light-sensitive photoreceptors
Involves the macula; this means that it is very rare that macular degeneration causes complete blindness. Your peripheral vision remains unaffected, but you may experience total loss of your central vision, which may be considered legal blindness

In Australia, around 1.4 million adults have some form of age-related macular degeneration. At the moment, there is no cure for this disease, but there are effective treatments to help slow the progression of certain types of macular degeneration.

Macular degeneration symptoms can be subtle. In the early and even intermediate stages of the disease, you may not notice any changes to your sight at all. Macular degeneration symptoms can include:

Blurry, dark, or indistinct areas around your central vision
Seeing straight lights as wavy or distorted
Difficulty with discerning fine detail despite glasses
Alterations to your colour perception
Difficulty recognising faces
Needing brighter task lighting for seeing objects or text up close

In most cases, macular degeneration symptoms progress slowly and can just be monitored by your eye care professional. However, any sudden changes to your sight should be addressed immediately, either with your ophthalmologist or even at the emergency department of your local eye hospital. Abrupt loss of sight can indicate an aggressive form of age-related macular degeneration known as the wet or neovascular form.

Macular Degeneration Causes

Doctors and researchers are still learning more about macular degeneration causes. We do know that the basic underlying mechanism of disease is that one particular layer of the retina, known as the retinal pigment epithelium, becomes damaged from years of accumulating waste material in its cells. This collection of debris causes disruptions under this layer; these bumps are known as drusen. One of the functions of the retinal pigment epithelium is to support the metabolic demands of the overlying photoreceptor layer. If the retinal pigment epithelium is unable to do its job properly, the associated photoreceptors also deteriorate and lose their function, leading to the characteristic macular degeneration symptoms of distorted, blurry central sight.

Despite understanding this pathophysiology of age-related macular degeneration, scientists don’t fully understand why it happens in the first place, and why it might develop in some people but not others. Through extensive research, several risk factors have been identified:

Older age; the older you are, the great your risk of developing age-related macular degeneration. The risk becomes more significant after the age of 50.
Family history; having a relative with macular degeneration increases your risk of developing the disease as well, due to shared genetics. Those with a first-degree relative (parent or sibling), have a 50% risk of developing macular degeneration.
Caucasian ethnicity; compared to all other races, Caucasians are at a higher likelihood of developing age-related macular degeneration.
Smoking; tobacco smoking increases your risk of macular degeneration by 2-3 times compared to a non-smoker.
Obesity; research has shown that being obese can increase your risk.
Cardiovascular disease; conditions that affect your heart and blood vessels, such as hypertension, can increase your risk.
UV exposure; the link between sunlight and age-related macular degeneration isn’t well established. However, there is some suggestion that UV exposure may play a part in developing the disease.

Is Macular Degeneration Preventable?

You may have noticed that some of the risk factors listed above can be controlled, while others are not modifiable. It is not possible to eliminate your risk of developing age-related macular degeneration entirely – unless you stop yourself from ever ageing past 50! However, based on what we know increases the risk of this blinding eye disease, doctors do have some suggestions that can help to reduce your likelihood of developing age-related macular degeneration.

Quit smoking
Keep yourself in good overall health, including managing (or preventing) any cardiovascular conditions and maintaining a healthy weight
Protect your eyes from UV. Although the association between UV light and macular degeneration isn’t strong, there is no harm in wearing sunglasses and a hat when outdoors, so many doctors continue to recommend this

The role of diet in age-related macular degeneration has also been recognised as important. Specifically, maintaining a healthy intake of antioxidants and omega-3 has been shown to be beneficial for the macula. This includes a daily intake of dark, leafy vegetables, and fresh fruit, as well as including nuts and oily fish in your diet.

Nutritional supplements are also available to boost macular health, particularly those based on a study known as AREDS2. However, the benefit of these supplements has only been demonstrated in those already with age-related macular degeneration. The AREDS2 formula may help to slow the progression of dry age-related macular degeneration.

Call us on (03) 9070 5753 today.

Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.

References

Age-related Macular Degeneration.
https://www.mdfoundation.com.au/about-macular-disease/age-related-macular-degeneration/AMD-overview/

Macular degeneration.
https://www.healthdirect.gov.au/macular-degeneration

Pathophysiology of age-related macular degeneration.
https://pubmed.ncbi.nlm.nih.gov/3299827/#:~:text=The%20clinical%20and%20histopathological%20features,takes%20place%20in%20all%20eyes

Signs of Retinal Detachment – Recognising the Condition

March 17, 2021/0 Comments/in Retinal Surgery /by The Armadale Eye Clinic Team

A retinal detachment is considered an ocular emergency requiring prompt treatment to save your sight. Although a retinal detachment is painless, without attention from an ophthalmologist experienced in retinal surgery, the vision loss can be permanent and significant. Knowing the symptoms and signs of a retinal detachment can enable you to seek help quickly.

What is a Retinal Detachment?

The retina is the layer of sensory tissue lining the back of the eye. It’s the cells of the retina that receive the incoming light from the world around us, convert it to neural signals, and transmit these signals via the visual pathways to the necessary processing centres of the brain for vision.

For the retina to function properly (and for vision to work), it needs to be able to access the basic necessities – a blood and oxygen supply, plus a metabolic waste removal system. The retina must also, of course, be physically able to send along its neural signals via a connected network of cells. A retinal detachment occurs when the retina is separated from its underlying layers, removing its access to the support it needs to function. Many eye care practitioners will describe a retinal detachment as like wallpaper peeling away from the wall. This results in a loss of sight in the area of the detached retina. A retinal detachment may occur just in one area of the retina, or in severe cases, the entire retina may come away, resulting in complete blindness in that eye.

Eyecare professionals will often refer to a retinal detachment case as “macula on” or “macula off”. The macula is an anatomical part of the retina responsible for your central vision. The status of the macula – whether it is detached or still attached – can determine how urgently retinal surgery needs to be performed. As the central vision is still intact in a macula-on retinal detachment, ophthalmologists will recommend prompt treatment, typically within 24 hours, in order to preserve the vision. However, in a macula-off detachment, as the prognosis is immediately much poorer for recovering the central vision, immediate retinal surgery is less critical. Nonetheless, treatment for a macula-off detachment is still recommended within 7-10 days for the best possible visual recovery.

While some retinal detachments occur for no identifiable reason, a situation known as an idiopathic retinal detachment, there are some known factors that can increase your risk. These include:

A history of trauma to the eye
A history of a previous retinal detachment
A family history of retinal detachment
Any degree of myopia (short-sightedness), with the risk of retinal detachment increasing as the degree of myopia increases
Older age
Certain eye operations, such as cataract surgery
Other eye conditions, such as a retinal hole or tear, diabetic retinopathy, or lattice degeneration

What are the Signs of a Retinal Detachment?

Signs of a retinal detachment include:

The sudden appearance of small floating specks within the eye, known as floaters. Typically, this presents as a shower of many tiny dark drifting flecks or sometimes as cobwebs or drifting lines or squiggles in the eye. Floaters from a retinal detachment are due to fragments of retinal tissue or drops of blood from broken retinal capillaries floating inside the eye.
The sense of flashing lights in the vision. This phenomenon is known as photopsia and is a result of the mechanical stimulation of the retina as it pulls away, giving the sensation of light perception.
A sudden darkening or loss of vision in one area of the eye. Some will describe this sensation as like a dark curtain coming across the vision. This dark shadow occurs in the area of the detached retina as it loses its ability to detect light.

Another eye condition known as a posterior vitreous detachment can often present with signs similar to a retinal detachment. A posterior vitreous detachment is a normal age-related change to the vitreous gel inside the eye that can also cause floaters and photopsia. While most cases of flashing lights and floaters are likely to be a posterior vitreous detachment, as these may also be a sign of a retinal detachment it is important not to simply dismiss these symptoms but still get checked by an optometrist or ophthalmologist. A posterior vitreous detachment can increase the risk of a retinal detachment by causing a hole or a tear during the process of the vitreous gel liquefying.

Treatment

A retinal detachment can be treated a few different ways, often depending on the location and size of the detachment. An ophthalmologist experienced in retinal surgery will counsel you on the most appropriate treatment, which may be:

Pneumatic retinopexy: the injection of a silicon gas bubble into the eye, which pushes the detached retina back into position.
Vitrectomy: surgical removal of the vitreous gel, so that it no longer pulls on the retina.
Scleral buckle: a band of silicon is sutured to the outside of the eyeball, which indents the wall of the eye inwards to encourage the retinal to reattach.

As a retinal detachment can have devastating consequences on vision, it’s important never to ignore your symptoms.

Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.