GCA in the orbit disrupts the ophthalmic artery (OA) and its branches, especially the central retinal artery (CRA) and posterior ciliary arteries (PCAs). The PCAs supply the choroid, which feeds the photoreceptors in the optic nerve head and outer third of the retina. The CRA perfuse blood to the inner two thirds of the retina. The ophthalmic artery also supplies blood to the extraocular muscles. Ischaemia of these structures causes diplopia and ophthalmoparesis. Moreover, GCA can affect intracranial and extracranial blood vessels, producing homonymous loss of the visual field because of stroke in the occipital cortex.[14]