Avastin Eye Injections: What Patients Should Know
How Avastin Works for Retinal Conditions
Understanding how bevacizumab works starts with understanding why certain retinal diseases cause vision loss. Many retinal conditions share a common driver, a protein in the body that signals abnormal blood vessel growth, and bevacizumab is designed to block that signal.
VEGF, or vascular endothelial growth factor, is a protein that signals the body to grow new blood vessels. In healthy tissue, this process is helpful. In the retina, the thin light-sensitive layer at the back of the eye, elevated VEGF can cause abnormal, fragile blood vessels to form. These vessels leak fluid or blood into the macula, the part of the retina responsible for sharp central vision. Over time, this leakage causes swelling that can damage retinal cells and lead to significant vision loss.
Bevacizumab is a type of medication called a monoclonal antibody, a lab-made protein designed to attach to a specific target in the body. It binds to VEGF-A, preventing the protein from reaching the receptors on blood vessel walls that would otherwise trigger abnormal vessel growth. By neutralizing the VEGF signal, the medication allows fluid in the retina to decrease and the retina to stabilize.
Avastin was originally developed for cancer treatment and was not designed specifically for eye conditions. However, because the same VEGF protein drives problems in both cancer tissue and the retina, retina specialists recognized its potential for eye use and began using it for intravitreal, or inside-the-eye, injections starting in 2005. The cancer-dose vial is sent to a compounding pharmacy, where it is divided into much smaller doses appropriate for injection into the eye. This off-label use has become one of the most commonly performed treatments in retinal care worldwide.
What the Research Shows
Bevacizumab has been studied extensively in large clinical trials. The evidence supports its effectiveness for several retinal conditions, and long-term data provide meaningful guidance on what patients can expect over time.
A major clinical study called the CATT trial compared bevacizumab to ranibizumab, sold under the brand name Lucentis, which is FDA-approved for wet age-related macular degeneration (AMD). The study enrolled more than 1,200 patients across dozens of clinical centers. Both medications produced equivalent vision improvements, with patients in each group gaining a similar number of letters on a standardized vision chart. This landmark research established that bevacizumab is an effective alternative to FDA-approved options for wet AMD.
A separate study conducted in the United Kingdom, called the IVAN trial, confirmed these findings. Both trials concluded that bevacizumab and ranibizumab produced similar visual outcomes in patients with wet AMD.
Beyond wet AMD, bevacizumab has been studied in patients with diabetic macular edema, a swelling of the central retina caused by diabetes-related blood vessel damage, and in patients with macular edema following retinal vein occlusion, a blockage of a vein that carries blood away from the retina. Research supports its effectiveness for these conditions as well, though your retina specialist will evaluate which treatment is most appropriate for your specific diagnosis.
Follow-up data from the CATT trial showed that approximately half of treated patients maintained visual acuity of 20/40 or better over five years. Some patients experienced gradual vision decline after the first two years, which is consistent with the natural progression of AMD. Overall, the long-term data confirm that ongoing anti-VEGF treatment, including bevacizumab, provides meaningful visual benefit for many patients with wet AMD.
What the Injection Involves
Many patients feel anxious before their first eye injection. Understanding the process from start to finish can help. Our retina specialists, Dr. Gaurav Gupta and Dr. Pranjal Thakuria, use a careful, patient-focused approach at every step to keep you as comfortable as possible.
Before the injection, your retina specialist will apply numbing drops to your eye so you do not feel pain during the procedure. An antiseptic solution is used to clean the surface of the eye and reduce the risk of infection. Some patients receive a small additional injection of numbing medication around the eye for added comfort. This preparation takes only a few minutes.
The injection itself takes just a few seconds. A very thin needle delivers the medication through the white part of the eye, called the sclera, into the vitreous, the clear gel that fills the inside of the eye. Most patients feel brief pressure rather than sharp pain. The full appointment, from check-in to departure, typically lasts between 30 minutes and one hour.
Mild redness at the injection site, a gritty feeling in the eye, or temporary blurred vision is common and usually resolves within a few hours to a day. Your specialist may check your eye pressure before you leave the office. You can return to most daily activities the same day.
- Avoid rubbing your eye for the rest of the day
- Avoid swimming, hot tubs, and dusty environments for a few days
- Arrange for someone to drive you home after the appointment
Treatment Schedule and Ongoing Care
Bevacizumab is not a one-time treatment. Most retinal conditions require a course of injections over time, and your schedule will be tailored to how your retina responds. Understanding the approach to treatment can help you plan ahead and stay consistent.
Treatment typically begins with injections every four to six weeks. Many patients receive monthly injections during the first few months to bring the condition under control. After the initial phase, your retina specialist will adjust the frequency based on your imaging results and any changes in your vision.
Many retina specialists use a strategy called treat-and-extend with bevacizumab. Once the retina is stable, the time between appointments is gradually lengthened. If fluid returns on imaging, the interval is shortened again. This approach reduces the number of office visits over time while maintaining close control of the condition.
Stopping injections early or allowing long gaps between treatments can allow fluid to return to the retina, which may cause further vision decline. Even when your vision feels stable, continued monitoring and treatment help protect the progress you have made. If you need to reschedule an appointment, contact your retina specialist as soon as possible to avoid delays in care.
Benefits and Risks
Like all medical treatments, bevacizumab has both proven benefits and known risks. Your retina specialist will review these with you and help you weigh the options based on your individual situation.
Multiple large clinical trials have confirmed that bevacizumab is effective for treating wet AMD, diabetic macular edema, and macular edema related to retinal vein occlusion. For many patients, consistent treatment successfully stabilizes or improves vision. Studies of large numbers of intravitreal bevacizumab injections have shown that serious complications are rare, occurring in less than one percent of cases.
The most common side effects after an injection are redness at the injection site, mild discomfort, floaters, and temporary blurred vision. These are typical of all intravitreal injections and are not unique to bevacizumab. They usually resolve on their own within a few days. Some patients also notice watery eyes or a sensation of something in the eye, which is also temporary.
Rare but serious risks of intravitreal injection include eye infection (a condition called endophthalmitis), retinal detachment, increased eye pressure, and bleeding inside the eye. Because bevacizumab is repackaged at compounding pharmacies, maintaining sterility during that process is an important quality consideration. Our practice uses bevacizumab sourced from regulated, reputable compounding facilities that follow strict quality and safety standards.
Seek immediate care if you experience sudden vision loss, severe eye pain, or rapidly worsening redness after an injection. These symptoms require prompt evaluation and should not wait until your next scheduled visit.
How Avastin Compares to Other Anti-VEGF Medications
Bevacizumab is one of several anti-VEGF medications used in retinal care. Your retina specialist will consider your diagnosis, treatment history, and individual needs when recommending which medication is right for you.
Several anti-VEGF medications are FDA-approved specifically for retinal conditions. Ranibizumab (Lucentis) is approved for wet AMD and is given monthly or on a treat-and-extend schedule. Aflibercept (Eylea) and high-dose aflibercept (Eylea HD) offer dosing intervals ranging from four to sixteen weeks. Faricimab (Vabysmo) targets both VEGF and a related protein called angiopoietin-2, which may allow longer intervals between treatments for some patients. Clinical trials have shown that bevacizumab produces visual outcomes comparable to these alternatives for wet AMD.
The most important distinction is that bevacizumab is not FDA-approved for use in the eye. It is a cancer treatment used off-label in ophthalmology, which means it must be repackaged from larger vials at a compounding pharmacy before use. FDA-approved retinal medications are manufactured in single-dose vials designed specifically for eye injection. Your retina specialist can explain the differences in detail and recommend the medication most appropriate for your specific condition and goals.
Monitoring and Recovery After Treatment
Ongoing care after each injection is an important part of protecting your vision. Your retina specialist will schedule regular follow-up visits to track how your retina is responding and adjust treatment as needed.
At follow-up appointments, your specialist will typically perform vision testing and retinal imaging. A scan called optical coherence tomography (OCT) takes detailed cross-section images of the retina to check for fluid or swelling. These results guide decisions about your treatment interval. Regular monitoring is important even when your vision feels stable, because early changes detected on imaging can be addressed before they affect your sight.
Certain symptoms after an injection should prompt you to seek care right away, without waiting for your next scheduled appointment. Contact your retina specialist or go to an emergency room immediately if you notice any of the following.
- Sudden loss of vision in one or both eyes
- Severe or rapidly worsening eye pain
- A significant increase in floaters or new flashes of light
- A curtain or shadow across part of your vision
- Increasing redness that does not improve
These symptoms could indicate a serious complication such as infection or retinal detachment, both of which require prompt treatment to protect your vision.
Conditions That May Be Treated with Bevacizumab
Bevacizumab is used off-label for a specific group of retinal conditions, all of which involve fluid or abnormal blood vessel growth in or under the retina. If you have received one of these diagnoses, your retina specialist can evaluate whether this treatment is appropriate for your situation.
Wet AMD is the most common condition treated with bevacizumab. It occurs when abnormal blood vessels grow beneath the macula and leak fluid, causing rapid central vision loss. Anti-VEGF injections are the standard of care for wet AMD, and bevacizumab is among the most widely used options. Early treatment generally leads to better visual outcomes than delaying care.
Diabetic macular edema occurs when diabetes-related vascular damage causes fluid to accumulate in the center of the retina. Retinal vein occlusion, a blockage of a vein that drains blood from the retina, can also cause macular swelling. Both conditions respond to anti-VEGF treatment, and bevacizumab has been studied for each. Your retina specialist will determine the most appropriate medication and schedule based on your imaging findings and overall eye health.
Frequently Asked Questions
These answers address questions that go beyond what is covered in the sections above. If you have additional questions, our team is glad to help during your appointment.
Off-label use is a well-established practice in medicine and is legal and common when clinical evidence supports the treatment. For bevacizumab, the level of clinical evidence is substantial, including large randomized trials with thousands of patients. The primary safety consideration specific to bevacizumab is the compounding process used to divide the cancer-dose vial into eye-appropriate doses. Our practice sources bevacizumab from regulated compounding pharmacies that follow strict sterility and quality protocols.
Newer anti-VEGF medications may offer longer dosing intervals or slightly different mechanisms of action, but they are not always the right fit for every patient. Your retina specialist considers your specific diagnosis, how your retina has responded to past treatment, your overall health, and other individual factors. Bevacizumab continues to be a clinically appropriate and widely used option for many patients, and the decision is always made on an individual basis.
Missing or delaying an injection can allow fluid to return to the retina, which may cause further vision decline. If you need to reschedule, contact our office as soon as possible to minimize the gap in treatment. You should not assume your vision is stable enough to skip an appointment without consulting your retina specialist, even if your vision feels unchanged. Regular imaging is the only reliable way to detect early fluid return before it affects your sight.
Many patients with wet AMD and other retinal conditions require ongoing treatment over the long term to maintain visual stability. Some patients are able to extend the time between injections significantly, while others need more frequent visits. The goal is always to use the minimum number of injections that keeps the retina stable, which is why regular imaging at each visit is so important. Your retina specialist will discuss realistic long-term expectations based on your specific condition.
Most patients experience some temporary blurred vision or light sensitivity after the procedure due to the numbing drops and the injection itself. For safety, we recommend arranging for someone else to drive you home from your appointment. Most patients feel comfortable returning to their normal routine, including driving, by the following day. If blurred vision or discomfort persists beyond a day, contact our office.
Schedule Your Retinal Care Appointment
Rhode Island Eye Institute brings together fellowship-trained retina specialists and advanced diagnostic technology to deliver expert care for patients with serious retinal conditions. Our team is committed to clear communication, careful monitoring, and personalized treatment plans designed around your vision and your life. We welcome patients from across Rhode Island and the surrounding region and are here to help you take the next step in protecting your sight.