Avastin intravitreal injection is a medical procedure used in ophthalmology to address various eye conditions. This treatment delivers medication directly into the vitreous, the jelly-like substance filling the middle of the eye. Its primary function is to help preserve and, in some cases, improve vision for individuals with specific retinal diseases.
Understanding Avastin and Its Action
Avastin, known scientifically as bevacizumab, is a type of medication called a monoclonal antibody. This engineered protein specifically targets Vascular Endothelial Growth Factor, or VEGF. VEGF plays a significant role in the growth of new blood vessels, a process that can become problematic in certain eye diseases.
By blocking VEGF, Avastin inhibits the formation of abnormal, leaky blood vessels within the eye. These fragile vessels can leak fluid or blood, leading to swelling and damage to the retina, particularly the macula, which is responsible for sharp, central vision. Avastin also helps reduce this fluid leakage and swelling.
While Avastin is approved for treating certain cancers, its use in ophthalmology is considered “off-label.” This means medical professionals use it based on strong scientific evidence and clinical experience. The dose for eye injections is significantly smaller than that used for cancer treatments, typically around 1.25 mg to 2.5 mg.
Eye Conditions Treated with Avastin
Avastin intravitreal injections are commonly prescribed for several eye conditions characterized by abnormal blood vessel growth or fluid leakage. One such condition is Wet Age-related Macular Degeneration (AMD), where abnormal blood vessels grow under the macula, leaking fluid and blood that can severely impair central vision. Avastin helps by blocking the VEGF that drives this abnormal vessel growth and leakage, aiming to slow vision loss and potentially improve sight for many patients.
Another condition is Diabetic Macular Edema (DME), a complication of diabetes where high blood sugar levels damage retinal blood vessels, causing them to leak fluid and swell the macula. Avastin reduces this leakage and swelling, which can help preserve vision in individuals with diabetes. Similarly, in Retinal Vein Occlusion (RVO), blockages in the retinal veins lead to fluid buildup and swelling in the macula. Avastin injections help to reduce this swelling and improve visual outcomes by targeting the VEGF released due to retinal damage.
Avastin may also be used for other neovascular eye diseases where abnormal blood vessel proliferation threatens vision, such as proliferative diabetic retinopathy. The medication works to shrink these delicate new blood vessels, preventing them from bleeding and causing further damage to the eye.
The Intravitreal Injection Process
Receiving an Avastin intravitreal injection involves steps to ensure patient comfort and safety. Upon arrival, patients review their consent form and have any questions answered by medical staff, ensuring they are fully informed about the procedure and follow-up care.
Before the injection, the eye is thoroughly prepared to minimize the risk of infection. Anesthetic eye drops are administered to numb the eye, making the procedure largely painless. The ophthalmologist will then clean the eye area with an antiseptic solution to further reduce the chance of complications. In some cases, a small instrument called a speculum may be used to gently keep the eye open during the injection.
The injection itself is a quick process, typically lasting only a few seconds. A very thin needle delivers Avastin directly into the vitreous. Patients may feel slight pressure or a quick prick as the needle enters the eye, but significant pain is uncommon due to numbing drops. After the medication is injected, the speculum, if used, is removed, and an antibiotic ointment may be applied. The procedure is often performed in a clean minor surgery room, allowing patients to go home the same day.
What to Expect After the Injection
After receiving an Avastin intravitreal injection, patients can expect a few common, temporary sensations. It is normal to experience mild discomfort, a gritty or scratchy feeling, or a foreign body sensation in the eye. Some individuals may also notice new floaters or small black spots in their vision immediately after the injection, which typically resolve within a few days. The injected eye may also appear slightly red or bloodshot at the injection site, a painless discoloration that usually fades within a week.
Following the procedure, specific instructions are provided to support healing and prevent complications. Patients are advised to avoid rubbing their eyes for at least the day after the injection. Prescribed antibiotic eye drops should be used as directed to minimize the risk of infection. It is also recommended to avoid swimming for at least three days to further reduce any infection risk.
Patients should be aware of signs that warrant immediate medical attention, although serious complications are rare. These include severe or worsening eye pain, a significant decrease in vision, increased redness of the eye, or new sensitivity to light. If any of these symptoms develop, contacting the eye specialist without delay is important. A follow-up appointment is typically scheduled to monitor the eye’s healing, assess the treatment’s effectiveness, and discuss the need for further injections, as the effect of Avastin is short-lasting and often requires multiple treatments to control the condition.