A Retinal Vein Occlusion is a blockage of a vein in the retinal circulation that causes the vein to leak blood and excess fluid into the retina.
The eye is like a round camera with lenses at the front and the film of the eye at the back. The retina is the film of the eye and is covered in arteries that carry blood to the retina and veins that drain the blood away.
Visual loss varies depending on the severity of the swelling from the fluid or blood leaking from the blocked retinal vein.
Retinal Vein Occlusions are more common in older patients over 60 and specifically affects patients suffering from cardiovascular conditions and uncommonly blood clotting disorders.
The most common risk factor for retinal vein occlusions is high blood pressure and this should almost always be addressed.
Retinal veins carry blood from the retina back to the heart for re-circulation. If one of these veins becomes blocked pressure rises in the blocked segment of vein, causing leakage of blood and fluid into the retina.
When the macular, the central part of the retina, is involved vision will be significantly affected.
Retinal Vein Occlusions are typically age-related. Common risk factors are:
High Blood Pressure
The symptoms of Retinal Vein Occlusion are:
Pain in the eye due to high pressure can occur as a complication of a severe central Retinal Vein Occlusion. This is called Neovascular Glaucoma and it is very important to have regular follow up and treatment as needed to avoid.
There are two types of Retinal Vein Occlusion:
Central Retinal Vein Occlusion (CRVO)
Central Retinal Vein Occlusion occurs when the major retinal vein, draining blood from the entire retina, is blocked.
Branch Retinal Vein Occlusion (BRVO)
The eye’s retina has one main artery and one main vein. When branches of the retinal vein become blocked, it is called branch Retinal Vein Occlusion (BRVO).
When the vein is blocked, blood and fluid spill out into the retina. This is caused by blockage of a smaller branch of the main retinal vein, resulting in damage to the area of the retina drained by this branch.
Visual loss varies but is not as severe as with a Central Retinal Vein Occlusion.
The treatment recommended will depend on the severity of the Retinal Vein Occlusion and the effect on vision.
Mild cases of Retinal Vein Occlusion may require no treatment, just monitoring. You may be referred back to your general medical practitioner for advice regarding diet or lifestyle modification, and/or treatment of high blood pressure.
More severe cases in which vision is reduced usually require treatment, such as:
Successful treatment of Retinal Vein Occlusion may take months or even years in severe cases.
Dependant on how advanced a patient’s Retinal Vein Occlusion is, patients can recover and regain most of their vision if treated. In some cases, some vision may not return.
Age related macular degeneration (AMD) is the leading cause of legal blindness and severe vision loss in Australia in people over the age of 55.
AMD is the deterioration of the central portion of the retina known as the macula. The macula is responsible for detailed vision necessary for reading, driving and recognising objects. AMD does not cause complete blindness.
As AMD is related to ageing, people over the age of 55 are most frequently affected. There is a 2% risk of developing AMD for middle aged people, and this increases to approximately 30% for people over the age of 75.
However, AMD it is not an inevitable consequence of ageing.
Those most at risk:
Age-Related Macular Degeneration damages the macula which causes the loss of the sharp central vision, the part of the eye that allows you to see fine detail but can leave the peripheral vision intact.
AMD symptoms usually develop gradually, symptoms include:
There are two types of macular degeneration: Dry and Wet. Everyone with AMD starts with Dry even if they are not aware of it, and it is almost always present in both eyes.
Dry AMD
The dry form of macular degeneration results in a gradual loss of central vision.
Although there is currently no treatment, the following can help slow disease progression and vision loss:
Wet AMD
The wet form is characterised by a sudden loss of central vision. This is as a result of abnormal growth of blood vessels, which leads to leakage of fluid and blood below the macula. This results in damage to the retina and in turn leads to the destruction of light sensitive cells that make up the macula. Wet AMD tends to cause more severe vision loss than dry AMD.
There is no accurate way to predict who will eventually develop wet macular degeneration, and not everyone with dry will do so.
Some degeneration of the macula is normal during aging.
In early-stage AMD, visual symptoms are generally mild and may or may not impact vision-related activities. As Macular Degeneration advances, later stages can result in progressive central vision loss with difficulty reading and recognising faces. AMD related
blind spots are different to the clouding of the eye’s lens causes by cataracts and are not correctable by cataract surgery or glasses. End-Stage AMD is the most advanced form of Age-Related Macular Degeneration (AMD) where the central vision is lost in both eyes, making it difficult to perform everyday tasks. End-Stage AMD can develop from the dry form of AMD or the fast progressing wet form. There are currently (2020) no drugs or treatments that can cure End-Stage AMD. I ne damage to the macula is permanent.
The following preventive measures have been suggested for slowing down the progression of macular degeneration:
Lifestyle Modifications
Some dietary guidelines include:
Supplements may be of value if a patient’s diet is inadequate. The AREDS study shows that taking the AREDS formula may reduce the risk of progression.
These supplements do not stop or reverse damage caused by AMD. The supplement formula consists of:
Currently (2020) the treatment of wet macular degeneration involves regular ongoing intravitreal injections. This is not a cure and requires ongoing treatment. In some specific unusual situation a type of laser treatment called photodynamic therapy may be used.
What If AMD is Untreated?
It is critical that wet macular degeneration be treated as soon as possible once symptoms have started. If left too long the treatment will not be effective. It is important to understand that if untreated central vision will deteriorate but complete blindness will not happen. Currently there are no proven treatments to reverse the effects of dry AMD.
Diabetic Eye Disease or Diabetic Retinopathy is a medical condition that damages the retina or film at the back of the eye. It can be very serious and cause significant vision loss and even blindness. Because it can affect the eye without any problems with vision until late in the disease, it is critical to have regular eye checks if you are diabetic.
Diabetic Retinopathy is a leading cause of blindness among working-age adults aged 25-74 in Australia.
All people with diabetes mellitus are at risk this includes both those with Type I diabetes and those with Type Il diabetes. The longer a person has diabetes, the higher their risk of developing eye problems. People who have persistently high blood glucose levels are at risk of serious vision loss and blindness. People with diabetes whose blood glucose is not at target levels are almost eight times more likely to develop Diabetic Retinopathy.
Other general health factors causing Diabetic Retinopathy are patients with elevated:
Good diabetes control is critical not only for diabetic retinopathy but all complications of diabetes.
Diabetic Retinopathy results from damage to the small blood vessels and nerve cells of the retina as a side effect of diabetes. Small blood vessels all over the body can be affected including in the heart, brain, kidney and feet.
There are three main types of retinopathy in diabetes, including:
Vision loss from Diabetic Retinopathy is usually preventable, provided it is diagnosed early and treated appropriately. The most important aspect of managing diabetic eye disease is good control of blood sugars and blood pressure.
Treatment is decided based on the type and severity of the disease, and your response to prior treatment. Treatment of diabetic retinopathy may include intravitreal injections often combined with retinal laser (panretinal photocoagulation). Maintenance and control of blood sugar levels can prevent progression to more serious stages of retinopathy. However, severe cases may require surgery. Treatment is not a cure as the underlying cause. Diabetes is a lifelong condition. Regular monitoring of the condition of the eye is important and additional treatment may be required.
