The blood-retina barrier which consists of tight junctions between the endothelial cells of the vasculature of the retina and the cell junctions between the pigmented retinal epithelium can be disrupted with the consequent leak of serum and blood cells in the retina and sub-retinal space (Kyhn, Warfvinge, Scherfig, Kiilgaard, Prause, Klassen, Young, Cour et al, 2009).
"Histopathologic studies suggest that these hypertensive retinopathy lesions result from small vessel arteriosclerosis, and continued elevated blood pressure results in retinal ischemia and breakdown of the blood-retina barrier. They parallel hypertensive microvascular changes described in the brain, such as concentric thickening of the arterial wall, intimal thickening, [and] medial hyperplasia," they explained.
The absence of Leishmania amastigote forms in the retina and optic nerve might be related to tropism of the parasite for certain tissues or to the presence of the blood-retina barrier. Amastigotes have not been commonly reported in nervous tissue.
London, Oct 13 (ANI): A single jab can now prevent people from losing their vision, thanks to researchers at Trinity College Dublin, Ireland, who have developed a new method to inject drug into the blood by weakening the otherwise impermeable blood-retina barrier.