What is an intravitreal injection?
This type of injection places medicine inside the eye, close to the retina. Only a very small quantity is used. The injection is given through the white of the eye using a tiny needle.
Why is an intravitreal injection performed?
The macula is the part of the retina responsible for your main, central vision. If the macula becomes swollen or “water-logged”, this can reduce your vision. Intravitreal injections can reduce macular swelling. This can often stabilise or improve your vision. By delivering the medicine directly into the eye, side-effects to the rest of the body are minimised. The commonest causes of macular swelling that are treated with intravitreal injections are wet macular degeneration, diabetic retinopathy, and retinal vein occlusions.
What is the intravitreal injection procedure?
The whole procedure takes around 15 minutes, although the injection itself only lasts a few seconds. We will lie you down in a comfortable position. You will receive an anaesthetic eye drop and then a sterilizing eye drop. Your eye and eye lids will be cleaned with an antiseptic solution, which can initially cause a stinging feeling. The eye is held open either by the assistant or with an instrument called a speculum as we need to keep your lashes clear of the injection site. The medicine is then injected into your eye. You may feel slight pressure and a momentary sharp feeling on the eye when this is done, but this part (the injection itself) normally lasts no more than 5-10 seconds.
What are the side effects?
After the injection your eye may feel gritty, it may look bloodshot, and you may see floaters or black/grey bubbles in your vision. These are common and resolve in a few days. If you experience severe eye pain or sudden/severe loss of vision, ring us straight away – or out of hours, attend A&E at the hospital. Rare but serious side effects include infection in the eye (endophthalmitis), cataract (clouding of the lens within the eye), retinal detachment, and bleeding inside the eye.
Will I need more injections?
You might be asked to come back for a follow-up consultation, or alternatively you might be booked straight back for another injection. If you having another Injection, it will usually be 1-2 months after your current one. However each eye is different, and we aim to individualise our treatment plan to every patient and their eye conditions accordingly.
You must not rub the eye following the injection or swim for at least 7 days, and you must keep all follow up appointments so the doctor can monitor your response to treatment adequately.