Ang II–induced effects of hypertension on retinal vessels lead to vascular changes, including intimal hyperplasia, hyaline degeneration, endothelial cell barrier dysfunction and breakdown of the blood–retina barrier (BRB), which promote exudation of serum proteins and lipids into the retina, leading to fluid accumulation (oedema) in multiple layers of the retina [[32], [33], [34]]. This evidence concerns the gene AGT and hypertensive disorder.