When are intravitreal injections given?
An intravitreal injection of anti-VEGF drugs may be recommended to treat Macular Oedema (swelling of central retina at the back of the eye) associated with conditions such as Wet Macular Degeneration, Diabetic Retinopathy, Retinal Vein Occlusion (blockage) or eye inflammation.
Lucentis and Eylea are anti-VEGF drugs that were originally developed to treat Wet Aged Related Macular Degeneration and have been approved for use in Australia for several years. These injections are now approved for use in Diabetic Eye Disease and for Retinal Vein Occlusion.
Avastin is a drug that was originally developed for bowel cancer and is usually given in large doses into a vein for this purpose. It is an anti-VEGF drug. It has not been approved by the Therapeutic Goods Administration (TGA) for use in the eye and is used off-label when injected into the eye for macular oedema.
The aim of treatment is firstly to prevent further loss of vision. Improvement in vision occurs in many patients, but certainly not all. In some patients, vision can worsen in spite of treatment.
It is not known how many injections will be required in the long term, or how frequently the injections need to be given; it is important to realise that this is a course of injections and not a cure. Each patient’s course of treatment is tailored to their specific needs.
How are Intravitreal injections given?
Anaesthetic drops are given 3-4 times to effectively numb the eye. Sometime a local injection of anaesthetic is given. An antiseptic solution is given to prevent infection. You will be asked to look in a particular direction to keep your eye still. When the injection is given, minimal discomfort is to be expected (equivalent to having blood taken from your arm) and many people feel a sudden pressure. The injection is quick and usually takes a couple of seconds.
What are the risks with intravitreal injections?
As with any medical procedure, there is a small risk of complications following intravitreal injections. Most complications that might occur are from the injection itself, rather than the drug. For most patients, the benefit of the treatment outweighs the small risk of injection injury.
The following are the major potential risks and side effects of anti-VEGF injections, but this is not a complete list of all risks. These risks are all rare. Significant loss of vision due to this treatment is very uncommon.
- Serious eye infection (less than one in 1,000 cases)
- 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
Systemic risks are also very rare, but stroke and heart attack have been reported.