Patrick Talty1, Marie Hickey-Dwyer, Susan J Wong, Karen E Kulas, Paul M Beer. 1. From the *Department of Ophthalmology, Mid-Western Regional Hospital, Limerick, Ireland; †Wadsworth Center, New York State Department of Health, Albany, New York; and ‡Department of Ophthalmology, Albany Medical College, Albany, New York.
Abstract
BACKGROUND: To determine intraocular levels of bevacizumab in a normal eye 24 hours after the injection of bevacizumab into the vitreous cavity. METHODS: Fluid and tissue samples were analyzed for unbound bevacizumab levels using microsphere immunoassays. RESULTS: After a loading dose of 2.5 mg (0.1 mL) of bevacizumab, levels of unbound drug could be detected in all tissue extracts 24 hours after its injection. At least 60.2% of the injected bevacizumab could be accounted for in this study. Levels of 0.06 mg (2.4%) of bevacizumab were recorded in the choroid. CONCLUSION: At 24 hours, unbound bevacizumab levels can be detected at the level of the choroid. Therefore, bevacizumab can reach the site where choroidal neovascularization develops. This explains its reported therapeutic effect.
BACKGROUND: To determine intraocular levels of bevacizumab in a normal eye 24 hours after the injection of bevacizumab into the vitreous cavity. METHODS: Fluid and tissue samples were analyzed for unbound bevacizumab levels using microsphere immunoassays. RESULTS: After a loading dose of 2.5 mg (0.1 mL) of bevacizumab, levels of unbound drug could be detected in all tissue extracts 24 hours after its injection. At least 60.2% of the injected bevacizumab could be accounted for in this study. Levels of 0.06 mg (2.4%) of bevacizumab were recorded in the choroid. CONCLUSION: At 24 hours, unbound bevacizumab levels can be detected at the level of the choroid. Therefore, bevacizumab can reach the site where choroidal neovascularization develops. This explains its reported therapeutic effect.