Intravitreal injections: what are they and how are they given?

How are intravitreal injections used in ophthalmology?

Intravitreal injections are used to treat retinal vascular conditions such as neovascular age-related macular degeneration (AMD), diabetic maculopathy, and macular oedema (fluid) associated with a retinal vein occlusion. They are injected into the back of the eye in order to stop/limit leakage from retinal blood vessels and develop due to increased vascular endothelial growth factor VEGF and/or intraocular inflammation.

What type of drugs are injected this way?

Anti-VEGF (vascular endothelial growth factor), or steroid implant can be injected into the eye. Approved anti-VEGF drugs include Lucentis, Eylea, Vabysmo and biosimilars. Steroid implants used by ophthalmologists are Ozurdex and Iluvien.

How are intravitreal injections given, and how many are usually needed?

Before undergoing the intravitreal procedure, patients will receive anaesthetic drops and/or an anaesthetic injection on the surface of the eye. They will also be given an antiseptic solution which will be used in order to clean the surface of the eye and the periocular skin (the skin of the eyelid or around the eye).

Following this, a speculum will be applied to the eyelids to keep the eye open during the procedure. The injection is given into the external quadrant of the eye while the patient is looking down or up. After the procedure, they may feel some pressure and see black floaters.

Are there any side effects or potential risks involved?

Like any medical procedure, intravitreal injections pose some risks. Small superficial haemorrhages and floaters are very common following the procedure. Other complications such as raised intraocular pressure, cataracts and retinal tear/detachment may occur, however, these are very rare. A severe intraocular infection called endophthalmitis may also occur, but again, is extremely rare, with an incidence of 1:1000.

How safe and effective are intravitreal injections?

Intravitreal injections are the standard of care for many retinal vascular conditions. The benefit of having the treatment outweighs the small risk of having complications. They are safe and effective in controlling many retinal vascular conditions and aim to improve or stabilise vision.

Initially, Anti-VEGFs are given monthly but the interval is slowly increased once the condition has reached stability in terms of vision and repeated macular scans called OCT (optical coherence tomography). Intervals between injections will be guided by the OCT appearance. Steroid implants are long lasting and are not indicated to treat neovascular AMD.

If you require intravitreal injections and would like to speak to Dr De Salvo, you can book an appointment through her Top Doctors profile today.