Pars plana

Pars plana is a part of the eye's ciliary body, which is a ring-shaped tissue located behind the iris. The ciliary body, including the pars plana, plays a crucial role in the production of aqueous humor, a fluid that nourishes the eye and maintains intraocular pressure. The pars plana is specifically located between the retina and the ciliary body's anterior portion, the pars plicata.

Anatomy

The pars plana is approximately 4 mm wide and is located in the posterior part of the ciliary body. It is named for its flat appearance, as "pars plana" translates to "flat part" in Latin. The pars plana is devoid of the ciliary processes that are found in the pars plicata, which gives it its flat appearance.

Function

The primary function of the pars plana is to produce aqueous humor. This clear fluid fills the anterior and posterior chambers of the eye, providing nutrients to the cornea and the lens, which do not have their own blood supply. The aqueous humor also helps to maintain the eye's shape by creating intraocular pressure.

Clinical significance

The pars plana is often the site of a surgical procedure known as a pars plana vitrectomy. This procedure involves the removal of the vitreous humor, a gel-like substance that fills the back of the eye, to treat various eye conditions such as retinal detachment, diabetic retinopathy, and macular hole.

See also

• Ciliary body
• Pars plicata
• Pars plana vitrectomy