Delivery of medications to the retina and vitreous cavity, known as intravitreal drug therapy, has greatly increased in the last several years. New medications are now available, and several are under development and are expected to greatly improve the treatment of numerous retinal disorders.
Intravitreal drug therapy was first used over 30 years ago, when antibiotics were injected into the eye to treat vision threatening eye infections. These injections were shown to be safe and effective. More recently, steroids, antivirals and antibodies which block abnormal blood vessel growth have been developed for intraocular use.
There are a number of medications now available for treatment of retinal disease. These medications work by reducing macular edema, stopping abnormal blood vessel growth, or reducing intraocular inflammation.
Macular Edema is caused by of a variety of retinal conditions, including macular degeneration, diabetic retinopathy, vein occlusion, and cystoid macular edema. Kenalog, a synthetic steroid, can “tighten” leaky vessels and reduce macular edema. Anti VEGF medications including Macugen, Avastin, Eylea, and Lucentis also reduce macular edema. These medications work by inhibiting VEGF, a substance which causes retinal vessels to leak.
Abnormal Blood Vessels occur in macular degeneration, diabetic retinopathy, central or branch vein occlusion, and retinopathy of prematurity. Abnormal blood vessels can result in severe visual loss. Anti VEGF medications including Macugen, Avastin, Eylea, and Lucentis reverse the growth of abnormal blood vessels and often prevent vision loss.
Intraocular Inflammation can cause scarring and cystoid macular edema. This leads to a progressive decline in vision. Intravitreal steroids can suppress inflammation for several months. Implantable devices are being developed which slowly release medicine for several years.
Intravitreal drug therapy is a major advance in the treatment of retinal disease. While usually safe, these treatments do have some risks for systemic and ocular complications. These risks should be weighed against the potential benefit of preservation and improvement of vision. In the future, more effective and longer acting agents are likely to be available. Talk to your doctor regarding your best treatment options.