pars plana

{{More citations needed|date=January 2021}}

The pars plana (also known as orbicularis ciliaris {{Cite book |last=Lee Ann |first=Remington |title=Clinical anatomy and physiology of the visual system |publisher=Elsevier |edition=3 |pages=47}}) (Latin: flat portion) is part of the ciliary body in the uvea (or vascular tunic, the middle layer of the three layers that comprise the eye).

It is about 4 mm long, located near the junction of the iris and sclera, and is scalloped in appearance.

The pars plana may not have a function in the post-fetal period, making this a good site of entry for ophthalmic surgery of the posterior segment of eyeball; this surgery is known as pars plana vitrectomy.