In a presentation to Hawaiian Eye 2010, Malik Y. Kahook, MD, said that Avastin (bevacizumab) stored for long periods of time shows evidence of increased large particulate matter. This debris can block the eye's trabecular network and lead to increased intraocular pressure (IOP) in patients being treated with the drug for wet AMD.
According to Dr. Kahook, "Avastin is not formulated for sitting in a plastic syringe for an extended period of time. It is also not formulated for sitting in a plastic syringe that has a rubber stop in it."
This may explain the 56 published reports to date showing IOP spikes up to 40 mm Hg in AMD patients treated with Avastin. This has not been seen with Lucentis (ranibizumab), which is stored in a glass syringe.
Dr. Kahook suggested that ophthalmologists should be careful of the quality of their repackaged bevacizumab, use syringes stored for less than 2 weeks and keep syringes refrigerated. Not shaking or tapping the syringe and possibly buying one's own vial might also be good practice.