Intravitreal injection is mode of drug delivery directly in vitreous cavity. Intravitreal injections are given for the management of disease involving the retina or vitreous. Three types of medicines are given through intravitreal injection.
Retinal diseases like diabetic retinopathy, retinal vein occlusions, macular degeneration, & macular edema causes rapid irreversible loss of vision and warrants immediate aggressive management. Infectious conditions like endophthalmitis may lead not only to loss of vision but also loss of eye if not treated properly in time. Different mode of delivery other than intravitreal injection like intravenous injection, oral medicines, topical eye drops do not achieve the adequate concentration of drugs needed to control the disease process, in the target tissue like retina or vitreous and there is also a risk of systemic side effects. So the intravitreal injections are the effective mode of drug delivery in target tissue without any significant risk of systemic side effects.
The procedure can be performed by an ophthalmologist in his office as an OPD procedure or in the sterile environment of operation theatre. Before the medication is injected, the eye is numbed with anesthetic eye drops to minimize discomfort. The eye is then cleaned with an antiseptic solution. The medication is then injected directly into the vitreous cavity of eye. Patients may experience some pain or scratchy sensations after the injection. Sometimes, patients can develop conjunctival haemorrhage (bleeding on the surface of the white of the eye), floaters, increased eye pressure and inflammation of the eye. These side effects typically resolve spontaneously or can be treated with eye drops. Other less common risks include infection, bleeding in the eye, retinal tears or detachment, and cataract formation.