Iris Blood Supply and Nerve Supply

 The iris is a complex and important part of the eye that plays a vital role in regulating the amount of light that enters the eye. The iris is supplied by both blood vessels and nerves, which provide the necessary oxygen, nutrients, and signals for the iris to function properly. In this article, we will discuss the blood supply and nerve supply of the iris, as well as the role they play in the proper function of the iris.

Blood Supply of the Iris

The iris is supplied by blood vessels that originate from the ophthalmic artery, a branch of the internal carotid artery. The blood vessels of the iris are made up of three main branches: the anterior ciliary vessels, the iridic vessels, and the posterior ciliary vessels.

  • Anterior ciliary vessels: The anterior ciliary vessels supply blood to the front of the iris and the ciliary body.
  • Iridic vessels: The iridic vessels supply blood to the stroma of the iris, which is the thick, fibrous layer of tissue that makes up the majority of the iris.
  • Posterior ciliary vessels: The posterior ciliary vessels supply blood to the back of the iris and the choroid.

The blood vessels of the iris provide oxygen and nutrients to the iris, which are essential for proper function. The blood vessels also play a role in maintaining the proper pressure inside the eye and regulating the size of the pupil.

Nerve Supply of the Iris

The iris is supplied by nerves that originate from the oculomotor nerve, the trochlear nerve, and the abducent nerve. The nerves of the iris are responsible for sending signals to the iris to control the size of the pupil and the amount of light that enters the eye.

  • Oculomotor nerve: The oculomotor nerve supplies the muscles of the iris that control the size of the pupil. It also controls the ciliary muscle that adjust the shape of the lens for near and far vision.
  • Sympathetic nerve: The sympathetic nerve regulates the dilation of the pupil in response to changes in light.
  • Parasympathetic nerve: The parasympathetic nerve regulates the constriction of the pupil in response to changes in light.

The nerves of the iris are responsible for sending signals to the iris to control the size of the pupil and the amount of light that enters the eye. They also play a role in maintaining the proper pressure inside the eye and regulating the size of the pupil.

Disorders of the Iris Blood Supply and Nerve Supply

Disorders of the iris blood supply and nerve supply can lead to a variety of eye problems, including:

  • Glaucoma: Glaucoma is a group of disorders that can cause damage to the optic nerve and lead to vision loss. It is often caused by an increase in the pressure inside the eye.
  • Uveitis: Uveitis is an inflammation of the uveal tract, which includes the iris. It can cause pain, redness, and blurred vision, and if left untreated, can lead to vision loss.
  • Pigmentary glaucoma: Pigmentary glaucoma is a rare type of glaucoma that is caused by the build-up of pigment granules in the iris and ciliary body.
  • Melanoma: Melanoma is a type of cancer that can develop in the uveal tract, specifically in the choroid, ciliary body, or iris. It can cause vision loss

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