This treatment involves having an injection into your eye to treat certain retinal conditions, such as wet macular degeneration, diabetic macular edema, retinal vein occlusion that cause abnormal blood vessels to grow and leak under the retina.
Patients with these conditions can lose central vision when abnormal blood vessels bleed under the retina at the back of the eye. A series of injections of anti-VEGF medicines are given into the back of your eye to stop these blood vessels growing and help control the leaking blood. This treatment is highly effective in preserving central vision in many people.
What is age-related macular degeneration (AMD)?
Age-related macular degeneration (AMD) is the leading cause of vision loss in people aged 50 years or older. It involves damage to the part of the eye called the macula. The macula is a small, but extremely important area located at the center of the retina, the light-sensing tissue that lines the back of the eye.
The macula is responsible for seeing fine details clearly. A person with AMD loses the ability to see fine details, both close-up and at a distance. This affects only the central vision. The side, or peripheral, vision usually remains normal. For example, when people with AMD look at a clock, they can see the clock’s outline but cannot tell what time it is, or they will lose the ability to recognize people.
What is different about “wet” AMD?
There are two types of AMD. Most people (about 75%) have a form called “dry” AMD, which develops when there is a waste build-up under the macula. This state is compatible with normal or near normal vision. A minority of patients with dry AMD can progress to the vision-threatening forms of AMD called “wet” AMD. Wet AMD occurs when abnormal blood vessels grow underneath the retina. These unhealthy vessels leak blood and fluid, which can prevent the retina from working properly. Severe damage leads to severe permanent loss of central vision, but the eye is not usually at risk of losing all vision (going ‘blind’) as the ability to see in the periphery remains.
How does an injection of the anti-VEGF medicines prevent visual loss?
Anti-VEGF medicines stop the abnormal blood vessels leaking, growing and then bleeding under the retina. Vascular endothelial growth factor (VEGF) is a protein that promotes the growth of new blood vessels. It also makes the blood vessels more leaky. Anti- VEGF medicines stop the growth of these new blood vessels. This prevents damage to the retinal light receptors and loss of central vision. These medicines are effective in preventing further central vision loss in up to 90% of treated eyes.
Is anti-VEGF treatment right for you?
Your ophthalmologist will determine if the treatment is appropriate for you. Only patients with active leaking of blood and fluid can benefit from it. The treatment that’s right for you will depend on the specific condition of your central retina (macula). We perform fluorescein angiography to determine whether there is leakage and photographs (optical coherent tomography) of the eye which show us the different layers of the retina to monitor the response to treatment.
How is the treatment given?
The drug is injected into your eye with a fine needle. Minimal discomfort is to be expected (equivalent to having blood taken from your arm). The procedure takes five to seven minutes, but the injection itself is over in less than 20 seconds. The injection is given with you in semi-reclined position in a chair. Local anesthetic drops are applied to numb your eye and minimize discomfort. Your eyelids and surface of the eye are cleaned to prevent infection. A small clip (speculum) will be used to keep the eye open . Further anesthetic is put into the eye. A few seconds later, the injection is given.
What happens after the treatment?
Most patients require a loading course of three injections at regular intervals of four to five weeks. After the first three courses of injections, the majority of patients will require further injections depending on the leakiness of the blood vessels. Patients will need to be reviewed at regular intervals (usually four to six weeks) when further treatment might be given to maintain the benefits of therapy.
What are the risks with these injections?
As with any medical procedure, there is a small risk of complications following anti-VEGF treatment. These risks are all rare. Significant loss of vision due to this treatment is very uncommon.
- Serious eye infection (one in 2,000 cases or less)
- Detached retina
- Increase in eye pressure
- Blood clots and bleeding in the eye
- Inflammation inside the eye
Some common side effects that could occur include:
- Red eye (there is usually a bleed on the white part/sub – conjunctival space at the point of injection, which clears in a week or two)
- Sore and gritty eye (slight ache and discomfort lasting a day or two)
• ‘Blobs’ or ‘small specks’ in your vision (‘floaters’) might be seen for a few days after the injection. Also, there could be transient flashing lights or swirls of light immediately after the injection
You might notice some discomfort and redness for the first few days after your treatment. This is often due to the nature of the antiseptic used. If your eye becomes progressively red, sensitive to light, swollen and painful, or your vision gets worse after the anti-VEGF treatment, you must seek medical help. This might indicate infection and normally occurs within the first week after the injection, but the risk is minimal.
There are no special precautions following intravitreal injections. You can travel, and if you have any of the above problems, please see an ophthalmologist. Avoid getting water into your eye or swimming for the first few days.