short posterior ciliary artery

The short posterior ciliary arteries are branches of the ophthalmic artery that supply the choroid and ciliary processes of the eye. There are typically 15 to 20 short posterior ciliary arteries, and they are the primary blood supply to the outer layers of the retina via the choriocapillaris, as well as to the optic nerve head.

The short posterior ciliary arteries pierce the sclera around the optic nerve at the posterior pole of the eyeball. After penetrating the sclera, they enter the choroid and branch extensively to form the choriocapillaris, a dense capillary network beneath the retinal pigment epithelium. Some terminal branches contribute to the circulation of the optic nerve head.

The short posterior ciliary arteries are involved in nourishing the outer retina, retinal pigment epithelium, and optic nerve head via the choroidal circulation and choriocapillaris. Because the outer retina lacks its own intrinsic blood supply, it depends on diffusion from the choroidal vessels supplied by these arteries.

Giant cell arteritis is a well-known condition associated with occlusion of the short posterior ciliary arteries, which may be involved in anterior ischemic optic neuropathy. Atherosclerosis, systemic hypertension, and diabetes may also be associated with impaired flow. Compromise of the choriocapillaris may be involved in retinal and macular disease.

Indocyanine green (ICG) angiography is particularly useful for evaluating the choroidal circulation supplied by the short posterior ciliary arteries. Fluorescein angiography can reveal choriocapillaris filling patterns. Optical coherence tomography angiography (OCTA) provides non-invasive imaging of choroidal flow, and color Doppler ultrasound can assess flow in the major ciliary vessels.