Intravitreal Injections

An intravitreal injection is a procedure to place a medication directly into the space in the back of the eye called the vitreous cavity, which is filled with a jelly-like fluid called the vitreous humor. The procedure is usually performed by a trained retina specialist in the office setting.

What are intravitreal injections used for? 

Intravitreal injections are used to administer medications to treat a variety of retinal conditions. Age-related macular degeneration (AMD), diabetic retinopathy and retinal vein occlusion are the most common conditions treated with intravitreal anti-VEGF drugs. There are now also injections used to slow the progression of dry AMD.  Intravitreal steroids are used in some eyes with diabetic retinopathy, retinal vein occlusion and uveitis. Antibiotic, anti-fungal and antiviral drugs are also used to treat patients with infections in the eye such as endophthalmitis and retinitis.

What kind of drugs can be given by intravitreal injection?

• Anti-VEGF drugs
• Complement inhibitors
• Steroids and other anti-inflammatory medications
• Antibiotics, antiviral and antifungal medications

The intravitreal injection procedure 

Intravitreal injections are performed in the office, often with the patient reclined in a chair. First, the eye is anesthetized using topical drops to minimize discomfort. The eye and the eyelids are then cleaned with an antiseptic to kill organisms that live around the eye in order to prevent infection. An eyelid speculum is often used to keep the eyelids open during the procedure. Once the eye is prepped for injection, you will be asked to look in a particular direction depending on the location of the injection while the medicine is injected through the sclera (the white part of the eye) with a very small needle. Typically, patients feel pressure, with minimal pain during the injection.

Safety and results 

Severe complications are very rare with intravitreal injections. The major risks are:

• Infection in the eye or endophthalmitis
• Inflammation in the eye or pseudoendophthalmitis (a non-infectious inflammatory reaction to some medications)
• Bleeding into the vitreous gel (vitreous hemorrhage)
• Retinal detachment

Sometimes there may be a small bleed or subconjunctival hemorrhage on the surface of the eye where the needle enters; this usually heals within a week.

What to expect after the injection

Sometimes after an intravitreal injection, you may get the feeling that “something is in your eye”. Preservative-free artificial tears are advised to help ease symptoms of surface irritation.

However, you should contact us if you experience signs and symptoms of complications, such as:

• Severe eye pain or discomfort
• Increased floaters after the first day
• Loss of vision

Repeated intravitreal injections 

Intravitreal injections have become the gold standard to treat a variety of many retinal diseases. The eye is uniquely suited for intravitreal injections because it acts as a closed, localized compartment that allows high, targeted doses of medications to reach the retina while avoiding severe side effects throughout the rest of the body. Their use has become much more common since the introduction of anti-VEGF medications in 2005. Intravitreal injections often need to be repeated in chronic conditions such as AMD, diabetic macular edema, and retinal vein occlusions, which require frequent office visits. Repeat injections are usually safely tolerated over several years. The need for a repeat injection is determined during the clinical examination. Research is underway that will hopefully provide longer-acting treatments in the near future.