Characterization of VEGF-induced retinal neovascularization in Dutch Belted rabbits using in vivo imaging.

Abstract

Purpose : To characterize a retinal neovascularization model in Dutch Belted (DB) rabbits using the latest state-of-the-art in vivo imaging capabilities.

Methods : Male 8-month old pigmented DB rabbits (KB Lidköpings Kaninfarm, Sweden) received 100µl bilateral intravitreal administration of vascular endothelial growth factor (VEGF) at a dose of 50 ng – 5,000 ng. The rabbits were followed for 14 days after the injection. Spectral-domain optical coherence tomography (SD-OCT) and fluorescein angiography (FA) were performed at baseline, prior to intravitreal injections, and every two days after injection. Qualitative and quantitative evaluation of in vivo imaging data were performed using Heidelberg Spectralis OCT imaging software (Heidelberg Engineering, Germany) and ImageJ software (NIH).

Results : Eyes that received intravitreal injections of 50 ng, 200 ng and 500 ng VEGF did not develop RNV, whereas eyes that received 5,000 ng of VEGF showed prominent RNV and vascular leak, which started on day 3 post-injection (leakage area of 7.44 ± 0.68 mm² [Day 3] vs 3.67 ± 0.59 mm² [Baseline], P<0.0001) and reached maximal vascular leakage on day 7 post-injection (leakage area of 10.2 ± 1.46 mm²). On follow-up day 10, the leakage area decreased close to baseline levels (4.21 ± 1.81mm² [day10] vs 3.67 ± 0.59 mm² [Baseline], p=0.99). No recurrence of RNV or vascular leak was observed in any group after follow-up day 10.

Conclusions : A prolonged increase in VEGF-induced vascular leakage in rabbits provide a useful preclinical model to study vascular pathology.

This is a 2020 ARVO Annual Meeting abstract.