Bevacizumab is a medication administered through an injection directly into the eye to manage various conditions that threaten vision. This treatment is a common procedure used by retina specialists to address diseases characterized by abnormal blood vessel growth or excessive fluid leakage at the back of the eye. Understanding the medication’s function, the procedure itself, and the potential outcomes can help patients prepare for this therapeutic approach.
How Bevacizumab Works in the Eye
Bevacizumab functions as an anti-Vascular Endothelial Growth Factor (anti-VEGF) agent, targeting a specific protein in the body. VEGF is a signaling protein that stimulates the formation of new blood vessels. In certain eye diseases, excessive VEGF production leads to the growth of fragile, abnormal blood vessels that leak fluid and blood into the retina.
The drug binds to VEGF, effectively neutralizing the protein and preventing it from attaching to its receptors on endothelial cells. This blockade halts the signaling cascade that promotes vascular leakage and the proliferation of problematic vessels.
The primary goal of this action is to reduce swelling and dry up the fluid that accumulates in the central part of the retina, known as the macula. This fluid buildup is the main cause of vision impairment in several serious conditions. The therapy is frequently used to treat wet Age-related Macular Degeneration (AMD), Diabetic Macular Edema (DME), and macular edema following Retinal Vein Occlusion (RVO).
Bevacizumab was initially developed and approved for the systemic treatment of certain cancers. Its use for eye conditions is considered “off-label” because physicians repurposed it after studies demonstrated its effectiveness for ocular neovascular diseases. Despite this status, the treatment has been widely adopted globally due to its established efficacy and safety profile for these eye conditions.
What to Expect During the Injection Procedure
The injection procedure is typically performed in an in-office setting designated for minor surgical procedures. The entire appointment is relatively quick once the patient is prepared. The medical team ensures the patient is comfortable and the eye is thoroughly anesthetized to minimize discomfort during the injection.
Strong numbing drops are applied to the surface of the eye, sometimes supplemented with a local anesthetic injection under the conjunctiva. The area is then prepared with an antiseptic solution, such as povidone-iodine, applied directly to the eye and surrounding tissue to prevent infection. This cleaning is important for maintaining a sterile environment.
To keep the eyelids open and prevent blinking, a small instrument called an eyelid speculum is briefly placed between the lids. The physician will ask the patient to look in a specific direction while the injection is administered into the white part of the eye, or the sclera. Patients may feel a sensation of pressure or a quick, subtle pinch, but the procedure itself lasts only a few seconds.
Immediately following the injection, the speculum is removed and the eye is rinsed. Patients may notice small specks or bubbles moving in their vision, which is the air or medication moving within the vitreous gel. The doctor often checks the eye pressure before a final application of antibiotic drops is given.
Potential Risks and Expected Results
Patients can expect minor, temporary side effects following the injection, which typically resolve within a few days. Common effects include irritation, mild scratchiness, or the sensation of a foreign object in the eye. Redness or blood on the white of the eye, known as a subconjunctival hemorrhage, is also common where the needle entered, but this is harmless and resolves on its own.
More serious complications are rare, but they should be discussed before treatment begins. The most concerning risk is endophthalmitis, a severe infection inside the eye. Other rare risks include retinal detachment and a sustained increase in intraocular pressure.
The primary expected result of Bevacizumab therapy is the stabilization or improvement of vision by reducing the leakage and swelling in the macula. For many patients, the goal is not necessarily to regain perfect vision, but to prevent further, irreversible vision loss caused by the underlying disease. The medication works relatively quickly to reduce the fluid, which can be measured during follow-up examinations.
Treatment is typically a long-term commitment, often beginning with a series of monthly injections until the eye condition stabilizes. The frequency is then personalized based on the patient’s response, as the effects of the drug gradually diminish over time. Continuing the therapy is necessary to maintain the reduced fluid levels and prevent the disease activity from returning.