It is more prevalent in homozygous HbSS type sickle cell disease.[2][5] The fovea can be found within the macula and is known as the center of the visual field.[7] Maculopathy in sickle cell retinopathy is due to long term changes of capillaries that interact at the fovea.[5] Although ischemic changes may be apparent on the retina, maculopathy may be asymptomatic at first leaving visual acuity unchanged.[5] Central retinal artery occlusion is a known feature of non-proliferative sickle cell retinopathy that has a low incidence in patients with non proliferative sickle cell retinopathy.[5] Optic nerve sign is represented by dilated capillaries that can be visualized in the nerve using fluorescein angiography.