Short posterior ciliary arteries

The short posterior ciliary arteries (SPCAs) are a group of arteries that play a crucial role in the blood supply to the posterior segment of the eye. They are responsible for delivering oxygenated blood to the choroid, which is the vascular layer located between the sclera and the retina. The SPCAs also supply blood to the ciliary body and the iris.

Anatomy

The SPCAs arise from the ophthalmic artery, which is a branch of the internal carotid artery. There are usually four to six short posterior ciliary arteries in each eye. They pierce the sclera near the optic nerve head and enter the choroid. Once inside the choroid, they divide into multiple branches that supply blood to different regions of the choroid, ciliary body, and iris.

Function

The main function of the short posterior ciliary arteries is to provide oxygenated blood to the choroid. The choroid is a highly vascularized layer that supplies nutrients and oxygen to the outer layers of the retina. The SPCAs also supply blood to the ciliary body, which is responsible for producing aqueous humor, and the iris, which controls the size of the pupil.

Clinical Significance

The short posterior ciliary arteries are crucial for maintaining the health of the posterior segment of the eye. Any disruption in their blood supply can lead to various eye conditions, including:

- Choroidal ischemia: Reduced blood flow to the choroid can result in ischemia, which can lead to vision loss and other complications. - Choroidal neovascularization: Abnormal blood vessel growth in the choroid can cause leakage of fluid and blood, leading to vision problems. - Anterior ischemic optic neuropathy: Inadequate blood supply to the optic nerve head can result in optic nerve damage and vision loss.

Internal Links

- Ophthalmic artery: The ophthalmic artery is the main artery that gives rise to the short posterior ciliary arteries. - Choroid: The choroid is the vascular layer of the eye that receives blood supply from the short posterior ciliary arteries. - Ciliary body: The ciliary body is a part of the eye that produces aqueous humor and receives blood supply from the short posterior ciliary arteries. - Iris: The iris is the colored part of the eye that controls the size of the pupil and receives blood supply from the short posterior ciliary arteries. - Choroidal ischemia: Choroidal ischemia is a condition characterized by reduced blood flow to the choroid, often caused by a disruption in the short posterior ciliary arteries' blood supply. - Choroidal neovascularization: Choroidal neovascularization is the abnormal growth of blood vessels in the choroid, which can lead to vision problems. - Anterior ischemic optic neuropathy: Anterior ischemic optic neuropathy is a condition characterized by inadequate blood supply to the optic nerve head, resulting in optic nerve damage and vision loss.

References

1. Cassin, B., & Solomon, S. (1990). Dictionary of Eye Terminology. Gainesville, FL: Triad Publishing Company. 2. Hogan, M. J., Alvarado, J. A., & Weddell, J. E. (1971). Histology of the Human Eye: An Atlas and Textbook. Philadelphia, PA: W.B. Saunders Company.

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  Gray's Anatomy illustration of short posterior ciliary arteries