The Use of PolyChromatic Angiography for the Assessment of the Effects of VEGF and Bevacizumab on the Rabbit Retina

Abstract

 

Purpose

 

To determine the utility of PolyChromatic Angiography (PCA) in the assessment of the response to different doses VEGF and bevacizumab .

 

Methods

 

Twenty six eyes of twenty four Dutch Belted rabbits were injected intravitreally with 1.25 µg (group A, n=5), 4 µg (Group B, n=6) and 10 µg (Group C, n=7), 4 µg (Group D, n=4) and 4 µg (Group E, n=4) VEGF on day 0. Groups D and E were also injected intravitreally with 1.25 µg and 12.5 µg bevacizumab, respectively, on day 2. On days 0,2,4,7, 11 and 14 PCA was performed using a contrast agent mixture composed of fluorescein sodium, Indocyanine green, PCM102 and PCM 107 and imaged by a modified TRC 50 VT fundus camera. PCA scores were given based on leaking fluorophores.

 

Results

 

On day 7, there was a statistically significant difference between group A (0.6 ±0.89, PCA Score± st. dv.) and both groups B (2.67± 1.37, p value = 0.0154) and C ( 3.33 ±0.52, p value = 0.00085). There was also a statistically significant difference between groups B and E (PCA score 0.75 ± 0.96, p value = 0.032) on day 7. On day 11, there was statistically significant difference between group C (1.80±1.1) and both groups A (0, p value=0.021) and B (0.33±0.52, p value= 0.037).

 

Conclusions

 

PCA is a useful tool for the assessment and grading of BRB dysfunction in the rabbit retina. PCA may become a useful diagnostic tool for grading disease severity in patients with similar pathologies.

 

 

PCA scores before, 2, 4 7 11 and 14 days after intravitreal VEGF injection in rabbits. Mean ± Standard deviation. * p≤0.05, **p≤0.001.

 

 

PCA scores before, 2, 4 7 11 and 14 days after intravitreal VEGF± bevacizumab injection in rabbits. Mean ± Standard deviation. * p=0.032, #p=0.08.

 

Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 700 retinal neovascularization • 688 retina