An increasingly common method of efficiently delivering medications to the retina is by direct injection into the vitreous cavity. The vitreous cavity is located behind the lens and in front of the retina. It is filled with a clear, collagenous gel called the vitreous humor. Intravitreal delivery of of medications offer several advantages. Drugs that are delivered directly at the site of action can be given rapidly at the lowest effective dose to eliminate side effects to the rest of the body. Some of the retinal diseases in which intravitreal injections are being used are retinal vascular disease, diabetic retinopathy, macular edema, neovascular glaucoma, endophthalmitis and most commonly for exudative or wet-type age-related macular degeneration. Although many patients are tentative to the idea of having a needle placed in the eye, most find the injection quite tolerable and find that the procedure sounds worse than it really is. The actual procedure takes only a few seconds.
The eye is anesthetized with a small amount of lidocaine jelly or by subconjunctival injection. Once the eye is anesthetized, the ocular surface is sterilized to reduce the risk of infection. Medications are injected via a small gauge needle through the conjunctiva and sclera. Topical antibiotic drops will be prescribed and sometimes your eye doctor will place an eye patch which can be removed upon returning home. There are no physical restrictions following the injection. The injection is generally safe and effective. Certain low risks associated with the injection itself may include the following: infection, bleeding, cataract and increased intraocular pressure.