Abstract
Purpose: :
To ascertain the dynamics of retinal and choroidal circulation during the early phase of fluorescein angiography (FA) in Abyssinian cats with rdAc, an autosomal recessive late-onset photoreceptor degeneration caused by a mutation in the CEP290 gene.
Methods: :
In vivo imaging with native confocal scanning-laser ophthalmoscopy (cSLO) and fluorescein and indocyanine green (ICG) angiography was performed in nine cats, eight of them classified ophthalmoscopically as rdAC stages 1 to 4, and one unaffected control cat. Respective AVI files of the early phase of FA performed with the HE HRA I (recording rate 12.3 Hz) were decomposed into single JPG images for further analysis.
Results: :
In all cats, we observed initial episodes of dye level fluctuation which we attribute to transit and mixing properties of fluorescein following injection in the femoral vein. In some cases, there was almost a complete intermittent wash-out of dye before an early steady-state was reached. The asynchrony of the filling patterns between retina and choroid often allowed to study the characteristics of each system separately. In particular, the lobular structure and details of the intralobular filling sequence of smaller vessels and the capillary lamina of the choroid became apparent. The overall degree of reduction and delay of intraretinal filling observed correlated well with rdAc disease stage.
Conclusions: :
In this study, we assessed the dynamics of retinal and choroidal blood flow during the early phase of fluorescein angiography in the rdAc cat model for human RP. In particular, we identified details of the intralobular filling sequence of the capillary lamina of the choroid. The findings may help to better understand the interplay between retinal and choroidal circulation in health and disease.
Keywords: imaging/image analysis: non-clinical • degenerations/dystrophies • blood supply