title: Pharmacokinetics of intravitreally injected bevacizumab in vitrectomized eyes.
abstract: OBJECTIVE
  To compare the pharmacokinetics (PKs) of intravitreally injected bevacizumab in vitrectomized versus nonvitrectomized control rabbit eyes.
  
  
  METHODS
  Twenty-five-gauge pars plana vitrectomy without lensectomy was performed in 17 right rabbit eyes (V) and 18 nonvitrectomized right rabbit eyes served as controls (C). After 1.25 mg/0.05 mL intravitreal bevacizumab (IVB) injections, eyes were enucleated at 1 h, 1, 2, 5, 14, and 30 days after the injection and immediately frozen at -80°C. Bevacizumab concentrations were determined after separation of frozen vitreous and aqueous humor (AH) compartments using indirect enzyme-linked immunosorbent assay. Bevacizumab concentration-time data were analyzed to obtain PK data.
  
  
  RESULTS
  Vitreous clearance of IVB consisted of 2 phases, the first fast distribution and second slow elimination phase. Clearance of IVB was accelerated in V eyes only during the first phase and not in the second phase. The vitreous concentration percent ratios between V and C eyes were 94.7% (1 h), 70.5% (1 day), 89.2% (2 days), 94.2% (5 days), 99.2% (14 days), and 79.1% (30 days). Overall vitreous half-lives were 6.99 and 7.06 days for V and C eyes, respectively (1.6-h difference).
  
  
  CONCLUSIONS
  Overall IVB PKs in rabbit eyes after vitrectomy without lensectomy are not substantially different from nonvitrectomized control eyes.
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jeeyun
authors.initials: J
authors.lastname: Ahn
authors.forename: Hyuncheol
authors.initials: H
authors.lastname: Kim
authors.forename: Se Joon
authors.initials: SJ
authors.lastname: Woo
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Park
authors.forename: Sunyoung
authors.initials: S
authors.lastname: Park
authors.forename: Duck Jin
authors.initials: DJ
authors.lastname: Hwang
authors.forename: Kyu Hyung
authors.initials: KH
authors.lastname: Park
mesh_terms: D020533:Angiogenesis Inhibitors / Q000493:pharmacokinetics*; D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000493:pharmacokinetics*; D001082:Aqueous Humor / Q000187:drug effects* / Q000378:metabolism; D000068258:Bevacizumab; D058449:Intravitreal Injections; D011817:Rabbits; D014018:Tissue Distribution; D014821:Vitrectomy; D014822:Vitreous Body / Q000187:drug effects* / Q000378:metabolism / Q000601:surgery
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab