title: Detection of aqueous VEGF concentrations before and after intravitreal injection of anti-VEGF antibody using low-volume sampling paper-based ELISA.
abstract: Intraocular vascular endothelial growth factor (VEGF) levels play an important role in the pathogenesis of blindness-related diseases, such as age-related macular degeneration (AMD). Here, we aimed to develop a paper-based enzyme-linked immunosorbent assay (P-ELISA) to analyze the suppression of aqueous VEGF concentrations following intravitreal injection (IVI) of anti-VEGF antibody (bevacizumab or ranibizumab). A total of 25 eyes with wet AMD, one with myopic neovascularization, and one with polypoidal choroidal vasculopathy were enrolled in this study. The limit of detection using P-ELISA was 0.03 pg/mL. Forty-six consecutive samples of aqueous humor were acquired. From all samples, 66.67% (10/15) achieved complete VEGF suppression (below the detection limit) within 5 weeks of receiving IVI of anti-VEGF antibody. Only 13.33% of samples (2/15) achieved complete VEGF suppression 5 weeks after receiving treatment. In some patients, elevated VEGF was still detected 5 weeks after receipt of anti-VEGF antibody, and all samples (10/10) were found to have elevated VEGF levels 49 days after treatment. Thus, we suggest that monthly IVI of anti-VEGF antibody may be required to ensure durable VEGF inhibition. Ultrasensitive P-ELISA can detect elevated VEGF at an earlier time point and may facilitate decision-making regarding appropriate treatment strategies.
authors.affiliation: Department of Ophthalmology, Taichung Veterans General Hospital, Taichung 407, Taiwan.|Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu 300, Taiwan.|Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taiwan.|Center for Translational Medicine, Department of Medical Research, Taichung Veterans General Hospital, Taichung 407, Taiwan.
authors.forename: Min-Yen
authors.initials: MY
authors.lastname: Hsu
authors.affiliation: Department of Ophthalmology, Taichung Veterans General Hospital, Taichung 407, Taiwan.
authors.forename: Yu-Chien
authors.initials: YC
authors.lastname: Hung
authors.affiliation: Department of Ophthalmology, Taichung Veterans General Hospital, Taichung 407, Taiwan.|Department of Ophthalmology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: De-Kuang
authors.initials: DK
authors.lastname: Hwang
authors.affiliation: Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu 300, Taiwan.
authors.forename: Shang-Chi
authors.initials: SC
authors.lastname: Lin
authors.affiliation: Department of Ophthalmology, Taichung Veterans General Hospital, Taichung 407, Taiwan.
authors.forename: Keng-Hung
authors.initials: KH
authors.lastname: Lin
authors.affiliation: Department of Ophthalmology, Taichung Veterans General Hospital, Taichung 407, Taiwan.
authors.forename: Chun-Yuan
authors.initials: CY
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology, Taichung Tzu-Chi Hospital, Taichung 40, Taiwan.
authors.forename: Hin-Yeung
authors.initials: HY
authors.lastname: Choi
authors.affiliation: Department of Radiology, Taichung Veterans General Hospital, Taichung 407, Taiwan.
authors.forename: Yu-Ping
authors.initials: YP
authors.lastname: Wang
authors.affiliation: Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan.
authors.forename: Chao-Min
authors.initials: CM
authors.lastname: Cheng
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000068258:Bevacizumab / Q000008:administration & dosage*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005123:Eye / Q000378:metabolism*; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000188:drug therapy / Q000378:metabolism; D008297:Male; D010209:Paper; D000069579:Ranibizumab / Q000008:administration & dosage*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab; D000069579:Ranibizumab