25 Jul Intravitreal Injections | Intraocular Drug Delivery Sytems
This is series of articles co-authored by John Sullivan, M.D., a retina specialist in Jacksonville, Florida. John and I trained together.
This is Part 1.
Intravitreal injections (IVT) have become a very popular procedure used by retina specialists over the last decade. Intravitreal injections have two unique advantages. By directly injecting medications into the eye, systemic (exposure to the rest of the body) exposure to the drug is minimized. Also, the eye’s natural barriers are bypassed and the amount of drug that reaches the eye surpasses the amount obtainable by topical drops or systemic administration (IV or drugs taken by mouth).
Retinal Diseases Treated by Injections
Intravitreal injections now allow retina specialists to treat a variety of diseases.
Wet macular degeneration is probably the most commonly retinal disease treated by anti-VEGF medications which are injected directly into the eye. Examples of anti-VEGF medications include Avastin, Lucentis, Macugen and Eylea.
Retinal vascular occlusions (RVO) include branch retinal vein occlusions (BRVO) and central retinal vein occlusions (CRVO) used to be treated only with laser treatment. Swelling of the macula (macular edema) is caused by loss of the normal blood supply of the retina. Steroids (e.g. Kenalog, Triesence), sustained release steroids (Ozurdex) and anti-VEGF intravitreal injections are now the mainstay of treatment.
Diabetic macular edema (DME) is a common complication of diabetic retinopathy. While laser treatment is still a valuable treatment option, intravitreal injections of steroids, Ozurdex, Iluvien and anti-VEGF are now saving the sight in many who can not have laser treatment.
Uveitis (intraocular inflammation, also called iritis) may be treated with injections of steroids or Ozurdex. Vitreomacular traction (VMT) can be treated with Jetrea. Cytomegalovirus (CMV) retinitis is treated with intravitreal Vitravene.
Intravitreal Injections are Increasing
The use intraocular injections has been rising from <3000 in 1999 to well over 1 million in 2008.
The rise in popularity can be attributed to efficacy (how well they work) and safety. Cost may be an issue, but only when we have competing therapies which produce similar results.