Retinal vascular disease has the potential to affect hundreds of millions of people,
with the inherent risk of vision loss related to cystoid macular edema. Although there
have been histologic evaluation of eyes having cystoid macular edema, the most recent
paper was published more than 30 years ago. In retinal vascular cystoid macular edema
fluorescein angiography, a modality that images the superficial vascular plexus, shows
increased leakage. Optical coherence tomography angiography has provided unprecedented
resolution of retinal vascular flow in a depth resolved manner and demonstrates areas
of decreased or absent flow in the deep vascular plexus colocalizing with the cystoid
spaces. There has been a large amount of research on fluid management and edema in
the brain, much of which may have analogues in the eye. Interstitial flow of fluid
as managed by Müller cells may occur in the retina, comparable in some ways to the
bulk flow in brain parenchyma, which is managed by astrocytes. Absent blood flow in
the deep retinal plexus may restrict fluid managementstrategies in the retina, to
include transport of excess fluid out of the retina into the blood by Müller cells.
Application of this theory may help in increasing understanding of the pathophysiology
of retinal vascular cystoid macular edema and may lead to new therapeutic approaches.