27 Aug How Many Intraocular Injections (eg Avastin) Are Too Many?
Intraocular anti-VEGF injections are commonly used to treat wet macular degeneration.
“Libbyextra” follows me on Twitter. She asked, “Is there a limit to the number of injections (Avastin) a patient can have?”
There are two ways to answer this.
I do not believe there are any physical restrictions limiting the number of injections an eye can be given. The injection requires use of a very small/thin needle placed in a portion of the eye that is avascular (without blood vessels). The entry area is minute and is accomplished without bleeding. The entry area is quite small and is self-sealing (don’t ask). Healing occurs rapidly without any permanent damage or scarring to the eye.
There are physiologic considerations limiting the number of injections. These are not related to the mechanics of the injection, but relate to the efficacy of the drug and toxicity issues. For instance, most of the time we stop additional injections is due to the fact that no additional drug is needed; the drug did its job and nothing more needs to be done. This is true in cases of macular degeneration and diabetic retinopathy. More specifically, the “wet” form of macular degeneration may have dried up and no additional treatment is warranted. Patients are monitored looking for signs of recurrence, and if found, additional injections will be prescribed.
Another reason to stop treatment; the drug isn’t working. No reason to continue a treatment that is not working or the drug is working, but the results are disappointing. This is common. Many times a patient with macular degeneration comes to the office having lost significant vision in one eye. Despite successful treatment, the vision may not return as much as we had hoped. Often a patient will elect to stop treatment, though successful, but the visual return is disappointing.
A last reason for limiting injections would be systemic side effects. There are rare, but serious, systemic ramifications of anti-VEGF injections. Should a heart attack or stroke develop, further treatment should cease.
Randall V. Wong, M.D.
Ophthalmologist, Retina Specialist