Abstract
Purpose: :
The Blood- Retinal Barrier (BRB) is formed by the retinal pigment epithelium and the endothelium of retinal vessels that form the outer and inner barrier, respectively. This barrier isolates the retina from the systemic blood circulation, creating the unique extracellular environment necessary for normal photoreceptor and neuronal function. Perturbations in the normal function of the BRB are known under many ocular conditions. In animal models quantification of BRB integrity is possible by measuring the concentration of non permeable dyes and radioactive compounds. However, since such approaches are not possible in humans, no established, clinically used method for localizing and quantifying BRB permeability exists. Therefore, in most human studies, BRB permeability is qualitatively evaluated mainly using fluorescein angiography and the extent of BRB dysfunction under various pathological conditions remains undetermined.
Methods: :
We present a novel, computer assisted method measuring BRB permeability changes using fluorescein angiography images.
Results: :
Using cluster analysis we are able to separate blood vessels from normal and pathological retina. This approach allows quantifying the spatial characteristics of BRB-dysfunction and its behavior with time under different pathological conditions and in response to treatment.
Conclusions: :
Our results suggest that BRB-disruption varies both in extent and temporal characteristics under different ocular related diseases. This method may assist in future studies of BRB integrity and the dynamics of BRB-disruption as well as assessing its functional implications.
Keywords: imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retina