A Quantitative and Standardized Method for the Evaluation of Choroidal Neovascularization Using MICRON III Fluorescein Angiograms in Rats

Wigg, Jonathan P.; Zhang, Hong; Dong, Yuchao

doi:10.1371/journal.pone.0128418

Cited by 15 publications

(8 citation statements)

References 34 publications

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“…Quantification of size and intensity of lesions of both FFA and IH were done using ImageJ (version 1.47) 21 as described in Wigg et al 34 . Briefly, a region of interest (ROI) was drawn around the CNV lesion, and the signal intensity and area were measured.…”

Section: Methodsmentioning

confidence: 99%

AAV2/8 Anti-angiogenic Gene Therapy Using Single-Chain Antibodies Inhibits Murine Choroidal Neovascularization

Hughes

O’Flynn

Gatherer

et al. 2019

Molecular Therapy - Methods & Clinical Development

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While anti-angiogenic therapies for wet age-related macular degeneration (AMD) are effective for many patients, they require multiple injections and are expensive and prone to complications. Gene therapy could be an elegant solution for this problem by providing a long-term source of anti-angiogenic proteins after a single administration. Another potential issue with current therapeutic proteins containing a fragment crystallizable (Fc) domain (such as whole antibodies like bevacizumab) is the induction of an unwanted immune response. In wet AMD, a low level of inflammation is already present, so to avoid exacerbation of disease by the therapeutic protein, we propose single-chain fragment variable (scFv) antibodies, which lack the Fc domain, as a safer alternative. To investigate the feasibility of this, anti-vascular endothelial growth factor (VEGF)-blocking antibodies in two formats were produced and tested in vitro and in vivo. The scFv transgene was then cloned into an adeno-associated virus (AAV) vector. A therapeutic effect in a mouse model of choroidal neovascularization (CNV) was demonstrated with antibodies in both scFv and immunoglobulin G1 (IgG1) formats (p < 0.04). Importantly, the scFv anti-VEGF antibody expressed from an AAV vector also had a significant beneficial effect (p = 0.02), providing valuable preclinical data for future translation to the clinic.

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Section: Methodsmentioning

confidence: 99%

AAV2/8 Anti-angiogenic Gene Therapy Using Single-Chain Antibodies Inhibits Murine Choroidal Neovascularization

Hughes

O’Flynn

Gatherer

et al. 2019

Molecular Therapy - Methods & Clinical Development

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“…En-face OCTA Procedure: Implementation of OCTA methods were optimized to either extract functional data, such as blood flow, or widefield high-resolution structural data in-vivo [5]. In this study, for wide field analysis, we were prioritizing analyzing structural data over flow data, as the accuracy of flow rate is currently undetermined.…”

Section: Methodsmentioning

confidence: 99%

“…CNV is clinically diagnosed with a variety of image-based methods, but most commonly with fluorescent angiography (FA) using either fluorescein or indocyanine green (ICG) dyes delivered intravascularly as a contrast agent [ 4 , 5 ]. Vascular leakage visualized by ICG or FA indicates the presence of altered vascular permeability; although, rare cases of anaphylaxis may occur with Fluorescein or ICG injections [ 6 ].…”

Section: Introductionmentioning

confidence: 99%

En-Face Optical Coherence Tomography Angiography for Longitudinal Monitoring of Retinal Injury

2019

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A customized Optical Coherence Tomography Angiography (OCTA) algorithm and Orthogonal OCT (en-face and B-Scans) were used for longitudinal assessment of retina murine vascular and tissue remodeling comparing photoreceptor ablation and laser-induced Choroidal Neovascularization (CNV). In the mouse model, we utilized a combined OCTA/OCT technique to image and quantify morphological and vascular features of laser lesions over time. This approach enabled us to monitor and correlate the dynamics of retina vascular and tissue remodeling as evidenced by swelling, edema, and scarring. From the OCT B-Scans, three stages of inflammatory progression were identified: the early response occurring within hours to day 3, the transition phase from 3–7 days, and the late stage of 7–21 days entering either the resolving phase or chronic phase, respectively. For the case of CNV, en-face OCTA revealed a transient non-perfusion of inner retina capillaries, specifically Deep Vascular Plexus (DVP), which corresponded to growth in lesions of a height of 200 µm or greater. Non-perfusion first occurred at 24 hours, persisted during edema and CNV formation days 7–14. In contrast, the acute inflammation induced photoreceptor damage, but no detectable alterations to the microvasculature were observed. We demonstrated that the en-face OCTA system is capable of visualizing capillary networks (∼5 µm) and the corresponding tissue remodeling and growth dynamics allowing for separating acute injury from CNV. For the first time, by using OCTA we observed the presence of the 5–10 μm capillary non-perfusion present in DVP as part of CNV formation and the associated wound healing in the retina.

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“…26 AF564 is a widely used polyclonal goat immunoglobulin G (IgG) that has proven to be a potent inhibitor of VEGF 164 . 20,[27][28][29] In direct enzyme-linked immunosorbent assays (ELISAs), approximately 20% cross-reactivity with recombinant human (rh) VEGF 165 and rhVEGF 121 is observed and < 2% cross-reactivity with rhVEGF-B, recombinant mouse (rm) VEGF-B, rhVEGF-C, rhVEGF-D, and rmVEGF-D is observed. 30 In addition, NaCl (Fresenius Kabi Deutschland GmbH, Bad Homburg, Germany) served as control.…”

Section: Laser Treatment and Drug Administrationmentioning

confidence: 99%

Imaging of Therapeutic Effects of Anti-Vascular Endothelial Growth Factor Inhibitors by Optical Coherence Tomography Angiography in a Rat Model

Meyer

Marx

Strack

et al. 2020

Trans. Vis. Sci. Tech.

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The aim of the study was to investigate optical coherence tomography angiography (OCTA) as a high-resolution in vivo imaging modality for monitoring therapeutic response to different vascular endothelial growth factor inhibitors in the rat model of laser-induced choroidal neovascularization (CNV). Further, OCTA findings were compared with fluorescein angiography (FA) and fluorescence microscopy. Methods: Laser treatment at day (D)0 was followed by intravitreal injection of aflibercept, AF564, and NaCl in dark agouti rats. Imaging with OCTA and FA was performed at D2, D7, D14, and D21. OCTA was compared to FA as well as confocal imaged flat mounts and analysis included quantification of CNV area, pixel intensity, vessel density, and number of vessel junctions. Results: Within laser lesions, neovascularization were visible especially in deeper retinal layers on OCTA, but not on FA images. Using OCTA, mean CNV area (D21) at the level of the outer nuclear layer (ONL) was 0.017 mm 2 following aflibercept administration, 0.016 mm 2 following AF564 and 0.026 mm 2 following NaCl injection (P = 0.04 and P = 0.03). Similar differences between treatment groups were determined by FA and histology, although the overall CNV area was always larger on FA due to dye leakage (P ≤ 0.0001, all layers). Conclusions: Compared to FA, OCTA imaging allows for a more precise and quantitative analysis of new blood vessel formation and therapeutic response to vascular endothelial growth factor (VEGF)-inhibitors, whereas it does not permit assessment of leakage. Translational Relevance: These findings suggest that OCTA may be particularly useful for the investigation of new treatment targets in the animal model.

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A Quantitative and Standardized Method for the Evaluation of Choroidal Neovascularization Using MICRON III Fluorescein Angiograms in Rats

Cited by 15 publications

References 34 publications

AAV2/8 Anti-angiogenic Gene Therapy Using Single-Chain Antibodies Inhibits Murine Choroidal Neovascularization

AAV2/8 Anti-angiogenic Gene Therapy Using Single-Chain Antibodies Inhibits Murine Choroidal Neovascularization

En-Face Optical Coherence Tomography Angiography for Longitudinal Monitoring of Retinal Injury

Imaging of Therapeutic Effects of Anti-Vascular Endothelial Growth Factor Inhibitors by Optical Coherence Tomography Angiography in a Rat Model

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