For some conditions an injection of medicine into the eye is needed. This is called an intravitreal injection.
Age-related macular degeneration (AMD), diabetic retinopathy and retinal vein occlusions are the most common conditions treated this way with anti-Vascular Endothelial Growth Factor drugs. These drugs help prevent the formation of new blood vessels that can worsen your vision, cause them to regress, and tighten leaky blood vessels. In addition, intravitreal or sub tenon's steroids are used in some eyes with diabetic retinopathy, retinal vein occlusion, cystoid macular edema and uveitis. The anti-VEGF drugs and steroids help to reduce fluid leakage associated with these disorders. Moreover, antibiotic, anti-fungal and anti-viral drugs are also used to treat patients with infections in the eye such as endophthalmitis and retinitis. Also, in some cases an injection is used to insert a small gas bubble to aid repair of a retinal detachment.
INTRAVITREAL INJECTION PROCEDURE
Intravitreal injections are performed in the office. First, the eye and eyelids are anesthetized with drops so the injection doesn’t hurt. Sometimes a small numbing injection may be given. After cleaning the area with 5% povidone-iodine, a speculum is used to keep the eyelids open during the injection.
Most patients feel pressure but little or no pain during the injection. After the injection, the speculum is removed and the eye is rinsed. The injection takes about 3 seconds, but the entire process from beginning to end is about 10 to 15 minutes.
Minor complications include a small amount of bleeding on the surface of the eye (like a bruise) that heals within a week.
Severe complications are very rare but include:
- Infection in the eye or endophthalmitis (rate is about 0.05%)
- Inflammation in the eye
- Bleeding into the vitreous gel (vitreous hemorrhage)
- Retinal Detachment
There is a temporary rise in the eye pressure that usually returns to baseline in 5-10 minutes. During that time, your vision will be blurry. After the pressure goes down, vision will return to the level before the injection. The eye pressure may take longer to normalize in patients with glaucoma.
WHAT TO EXPECT AFTER THE INJECTION
Avoid touching your eye for 24 hours after the injection.Contact our office if you experience signs and symptoms of complications, such as:
- Severe eye pain or discomfort
- Increasing floaters after one day (a few floaters noted immediately after the procedure will go away in about 2 days).
- Increased sensitivity to light after one day.
- Worsening vision
After an intravitreal injection, you may get the feeling that “something is in your eye”. This can be a reaction to the soap used to clean the eye (5% povidone-iodine). Artificial tears (preferably sterile single use droppers) can be used to help ease symptoms of dryness and surface irritation. A follow-up visit with your retina specialist will be scheduled depending on the disease being treated, but is usually about 4 to 12 weeks after the injection.
REPEATED INTRAVITREAL INJECTIONS
Intravitreal injections often need to be repeated in chronic conditions such as macular degeneration, diabetic macular edema, and retinal vein occlusions, which also require frequent office visits. Repeat injections are safely tolerated over many years. The need for a repeat injection is determined during your visit. Research is underway that will hopefully provide longer-acting treatments