Bevacizumab is a medication administered by injection into the eye to manage conditions affecting the retina, the light-sensitive tissue at the back of the eye. This treatment is a standard procedure for specific retinal diseases that can lead to vision loss. This article covers the purpose of these injections, the procedure, and the recovery process.
Purpose of Bevacizumab Injections
Bevacizumab’s primary function is to counteract a protein called vascular endothelial growth factor, or VEGF. In certain retinal diseases, the body produces excessive VEGF, promoting the growth of abnormal, fragile blood vessels. These vessels can leak fluid and blood into the macula, the part of the retina responsible for sharp, detailed vision. As an anti-VEGF medication, bevacizumab binds to this protein to reduce the growth of these damaging vessels and decrease leakage.
This treatment is effective for several conditions. One of the most common is the “wet” form of age-related macular degeneration (AMD), where this abnormal blood vessel growth is the main cause of rapid central vision loss. Other conditions include diabetic macular edema, a swelling of the macula in people with diabetes, and macular edema from retinal vein occlusions, which are blockages in the veins that carry blood from the retina.
The use of bevacizumab (brand name Avastin) for eye conditions is an “off-label” use. The medication was originally approved by the FDA to treat certain cancers by inhibiting blood vessel growth in tumors. Extensive studies have since shown it to be safe and effective for ophthalmic purposes, leading to its widespread adoption by retina specialists.
The Eye Injection Procedure
While the thought of an eye injection can cause apprehension, the procedure is a quick outpatient process. Before the injection, a clinician will check your vision and eye pressure. The eye is then prepared with anesthetic drops or gel to completely numb its surface and prevent pain during the injection.
Once the eye is numb, the surrounding area is cleaned with an antiseptic solution to prevent infection. A small device called an eyelid speculum is placed to hold the eyelids open and prevent blinking. You will be asked to look in a specific direction to position the eye for the injection.
The injection is administered into the vitreous, the jelly-like substance that fills the back of the eye. A very fine needle delivers the medication through the sclera, the white part of the eye. Patients feel only a moment of slight pressure, and the injection is over in seconds. Afterward, the speculum is removed, and your eye’s pressure and vision are checked before you go home.
Recovery and Potential Side Effects
Following the injection, it is common to experience minor and temporary sensations. Many patients report a mild scratchy or irritated feeling in the eye. You might also notice redness on the white of the eye at the injection site, a small bruise (subconjunctival hemorrhage) that resolves within a week or two. The appearance of new “floaters” may also occur as you see the medication moving within your eye.
These side effects are not a cause for alarm and the initial irritation often subsides within a day. Your doctor will provide instructions on managing discomfort, which may include using lubricating eye drops. It is important to avoid rubbing the eye after the procedure to allow it to heal.
While serious complications are rare, you should contact your eye doctor immediately for certain warning signs. Seek prompt medical attention if you experience any of the following:
- Severe or worsening eye pain
- A significant decrease in vision
- Increased sensitivity to light
- Signs of infection, such as swelling or discharge from the eye
Treatment Schedule and Outlook
Bevacizumab injections are not a one-time cure but a long-term strategy to manage a chronic disease. The goal is to stabilize vision and prevent further decline, though some patients may experience an improvement in their sight. The response to treatment can vary between individuals.
Treatment often begins with an initial series of injections, administered monthly for the first few months. This loading phase helps bring the disease activity under control. After this period, your retina specialist will assess your eye’s response, often using imaging tests like optical coherence tomography (OCT) to check for fluid in the macula.
Based on this assessment, the time between injections may be increased using a “treat-and-extend” protocol. For example, if the eye remains stable and dry, the interval to the next injection might be extended by two weeks at a time, up to a maximum of 12 weeks. If the disease shows signs of recurring, the interval is shortened to regain control. This personalized approach maintains vision with the fewest injections necessary.