Intraocular bevacizumab levels 24 hours after intravitreal injection in a normal eye.

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.

Does extended wear of a tight necktie cause raised intraocular pressure?

PURPOSE: To investigate the effect that extended wear of a tight necktie has on the intraocular pressure (IOP), measured by Goldmann applanation tonometry in a normal and aged-matched glaucoma group. METHODS: One eye of 18 normal and 19 primary open-angle glaucoma patients was included in this prospective study. The intraocular pressure of each patient's randomly selected eye was measured with the patient dressed in an open shirt collar, again 3 minutes after their collar was fastened and necktie tightened, again after a further 12 minutes, and finally 3 minutes after the necktie was loosened and collar unfastened. The same examiner performed all measurements in a masked fashion. RESULTS: The mean intraocular pressure in the normal group (n = 18) increased by 0.56 mm Hg (P = 0.30) and increased significantly (*) in the glaucoma group (n = 19) by 1.58 mm Hg (P = 0.001*) after tightening the necktie for 3 minutes. The mean IOP then decreased after leaving the necktie on for a further 12 minutes, by 0.89 mm Hg (P = 0.08) in the normal group and decreased significantly by 0.94 mm Hg (P = 0.04*) in the glaucoma group. Finally after loosening the necktie for 3 minutes (immediately after 15 minutes of continuous necktie wear) the mean IOP decreased in the normal group by 0.89 mm Hg (P = 0.02*) but only minimally in the glaucoma group by 0.16 mm Hg (P = 0.72). The patient's age or collar size showed no significant correlation with the change in mean IOP following tight necktie wear. CONCLUSION: A significant increase in IOP after 3 minutes of tight necktie wear occurred only in the glaucoma group, but this increase was followed by a significant decrease in IOP after 15 minutes of tight necktie wear. Avoidance of wearing a tight necktie over an extended period is therefore not necessary in patients with glaucoma.