Aflibercept clearance through the drainage system in a rat model

Yariv Keshet*, Orly Gal-Or, Michal Schaap Fogler, Karin Mimouni, Meydan Ben Ishai, Dov Weinberger, Assaf Dotan

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Background: As intravitreal anti-VEGF injections became the mainstay of treatment for many retinal diseases, the cause of a secondary sustained elevated intraocular pressure is still unclear. The aim of our study was to study the clearance of Aflibercept from the anterior chamber angle, in a rat model, to test if an aggregation exists. Methods: Choroidal neovascular lesions (CNV) were induced in the right eye of 12 brown Norway rats, using indirect laser ophthalmoscope. Intravitreal Aflibercept injection (0.12 mg/3 µl) was performed 3 days after CNV induction. Rats were euthanized at predetermine time intervals of 3, 6, 24 and 48 h post injection, with immediate enucleation for histological analysis with H&E and immunofluorescence staining. Aflibercept molecules were stained with red fluorescence thanks to the formation of the immune complex Aflibercept-Rabbit anti human IgG-Anti rabbit antibodies-Cy3. Results: Immediately after the injection, a strong fluorescence signal was detected, indicating the presence of Aflibercept in the iridocorneal angle. At 3- and 6-h interval a strong signal of Aflibercept was still seen. Six hours post injection, the signal was highly concentrated in Schlemm’s canal. In the 2 eyes harvested 24 h post Aflibercept injection, red fluorescence signal intensity was decreased in one eye, occupying mainly intra scleral venous plexuses, and absent in the other eye. At 48 h there was no fluorescence signal, confirming complete clearance of Aflibercept. Conclusions: In our rat model, a complete clearance of Aflibercept from the anterior chamber angle, was seen 48 h after the injection. This finding refutes the theory of possible connection between IOP elevation and mechanical obstruction. Evacuation time of Aflibercept through the angle is of the same magnitude as that of Bevacizumab in the same rat model.

Original languageEnglish
Article number53
JournalInternational Journal of Retina and Vitreous
Issue number1
StatePublished - Dec 2021


FundersFunder number
Claire and Amedee Martier Institute for the Study of Blindness
Visual Disorders
Claire and Amédée Maratier Institute for the Study of Blindness and Visual Disorders, Tel Aviv University0601248452
Sackler Faculty of Medicine, Tel-Aviv University


    • Aflibercept
    • Angle
    • Brown Norway
    • Choroidal neovascularization
    • Clearance
    • Intraocular pressure
    • Rats
    • Retina


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