ABSTRACT
BACKGROUND: Vitreous levels of unbound bevacizumab (Avastin) and unbound vascular endothelial growth factor (VEGF) were determined in two patients. Patient 1 underwent repair of an 8-day-old rhegmatogenous retinal detachment 4 weeks after a single intravitreal bevacizumab injection, and Patient 2 underwent vitreous biopsy for endophthalmitis 48 hours after a combined bevacizumab and triamcinolone injection. METHODS: The samples of vitreous fluid were analyzed for unbound bevacizumab and unbound VEGF levels using microsphere immunoassays targeted for bevacizumab and VEGF. RESULTS: In Patient 1, the unbound bevacizumab level was 0.16% of the loading dose (or 500,000 pg/mL) and the unbound VEGF concentration was <41 pg/mL 4 weeks after the bevacizumab injection. In Patient 2, the unbound bevacizumab level was 53% of the loading dose (or 166,000,000 pg/mL) at 48 hours, with an unbound VEGF level of <41 pg/mL. CONCLUSION: A single dose of intravitreal bevacizumab is likely to provide complete intravitreal VEGF blockade for a minimum of 4 weeks, with an intravitreal bevacizumab half-life of approximately 3 days.
Subject(s)
Angiogenesis Inhibitors/pharmacokinetics , Antibodies, Monoclonal/pharmacokinetics , Vascular Endothelial Growth Factor A/metabolism , Vitreous Body/metabolism , Aged , Angiogenesis Inhibitors/therapeutic use , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal, Humanized , Bevacizumab , Biological Availability , Biopsy , Choroidal Neovascularization/drug therapy , Drainage , Endophthalmitis/diagnosis , Female , Humans , Immunoassay , Injections , Laser Coagulation , Male , Retinal Detachment/surgery , Vascular Endothelial Growth Factor A/immunology , VitrectomyABSTRACT
PURPOSE: To describe a patient with choroidal metastasis from renal cell carcinoma that spontaneously regressed after nephrectomy. DESIGN: Interventional case report. METHOD: A 48-year-old Hispanic woman presented with reduced vision in the left eye attributable to an elevated choroidal lesion and associated exudative retinal detachment. Oncology workup revealed a left kidney renal cell carcinoma with pulmonary metastases. The patient underwent primary nephrectomy, without specific treatment of choroidal or pulmonary metastases. RESULTS: The metastatic choroidal lesion regressed and the retinal detachment completely resolved, as evidenced by fundus photographs and ultrasonography. CONCLUSIONS: Choroidal metastasis from renal cell carcinoma may spontaneously regress after removal of the primary tumor.
