What is Pars Plana?
The pars plana is the posterior part of the ciliary body, located in the middle of the eye. Pars plana is also known as orbicularis ciliaris. In Latin, pars plana translates to “the flat part.” It represents the flattest part of the ciliary body. The pars plana is the location often used by ophthalmologists to make an incision into the eye. It is the preferred entry point for ophthalmic surgery, such as pars plana vitrectomy surgery which removes the vitreous (jelly-like substance in the eye) by making an incision through the pars plana.
Key Takeaways
- The pars plana is the posterior part of the ciliary body inside of the eye.
- The pars plana is the location where incisions are made for eye surgery. It is a safe location to cut through to access the inside of the eye without damaging its structures.
- A pars plana vitrectomy is an eye surgery that removes the vitreous (jelly) of the eye by cutting through the pars plana.
Understanding Pars Plana
Pars plana is the posterior side of the ciliary body. The ciliary body is responsible for eye focusing, aqueous fluid production, and making the eye’s collagen. The ciliary body has three main parts: the pars plana, pars plicata, and ora serrata. The pars plicata is the anterior zone of the ciliary body. The pars plana is the posterior zone of the ciliary body. The ora serrata is the transition zone where the ciliary body becomes the peripheral retina.
Pars plana is a four millimeter wide zone on the back side of the ciliary body. It is considered the safest entry point into the eye. A pars plana vitrectomy is a common eye surgery done for retinal conditions like retinal detachment and macular holes.
Pars Plana Vitrectomy
Pars plana vitrectomy surgery is done to remove the vitreous from the eye. The vitreous is the jelly-like substance that fills the back of the eye. It is made of water, collagen, and hyaluronic acid. A pars plana vitrectomy surgery removes the vitreous and replaces it with silicone oil or a gas bubble.
Reasons why a pars plana vitrectomy may be performed are:
- Retinal detachment
- Vitreous hemorrhage
- Retained lens fragments after cataract surgery
- Endophthalmitis
- Epiretinal membrane
- Macular hole
- Vitreomacular traction
Pars plana vitrectomy with membrane peel is a two-step surgery done for an epiretinal membrane. An epiretinal membrane is a shiny, wrinkly layer of glial cells that often occur with older age. In a pars plana vitrectomy with membrane peel, the vitreous is removed and the epiretinal membrane is peeled off.
Pars Planitis
Inflammation of the pars plana is called pars planitis, and could be infectious or non-infectious. White blood cells enter the eye, clump together, and block the vision. People with pars planitis may see ‘floaters’. Treatment for pars planitis is important as it can lead to the loss of vision, and can include topical, intraocular and systemic medications. Sometimes surgery may be needed.
