An Overview of Pars Planitis

Symptoms, causes, diagnosis, treatments, and prognosis

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Pars planitis is an eye disease where the middle layer of the eye, called the uvea, becomes inflamed. The uvea house three structures of the eye, including the iris—which you’re probably most familiar with—the ciliary body, and the choroid. The uvea also houses the blood supply for the retina.

The pars plana, the region of the eye for which the disease is named, is part of the ciliary body, and the ciliary body is located between the iris and the choroid. If the pars plana become inflamed, you may experience symptoms like blurry vision, floaters in the visual field, and eventually, vision loss. Pars planitis can affect one or both of your eyes, however, in many cases the disease is treatable.

Pars planitis may be known by other names as well, including:

  • Intermediate uveitis (IU)
  • Peripheral retinal inflammation
  • Vitritis
  • PP

People who are most at risk of developing pars planitis are young men just slightly more than women, according to the Genetic and Rare Diseases Center (GARD) of the National Institutes of Health (NIH). To date, the cause of the disease is idiopathic, or unknown, but it may be linked to other autoimmune diseases, like multiple sclerosis (MS), lupus, or sarcoidosis.

The Anatomy of the Eye and How It Works

Symptoms

The symptoms of par planitis can range from mild in the beginning stages of the disease to more severe as it advances. The symptoms include:

  • Blurred vision
  • Dark floaters in the visual field that may interfere with sight
  • Swelling inside the eye
  • Vision loss
  • Glaucoma
  • Cataracts (as the disease progresses)
  • Retinal detachment (as the disease progresses)

Causes

Often, the cause of pars planitis is unknown. However, the National Organization for Rare Diseases (NORD) notes that the disease may be an autoimmune condition where the inflammation in the eye is a result of an autoimmune reaction.

In autoimmune disorders, the body’s immune system begins to attack the healthy tissues of the body instead of foreign invaders and pathogens. Also, you may be more likely to develop pars planitis you if you have an existing autoimmune disorder.  

In some instances of pars planitis, more than one family member has experienced the eye disease, suggesting there may be a genetic component to the illness. To date, however, researchers haven’t identified a specific gene or the way in which it could be inherited from one person to another.

Other Potential Causes

  • Injury to the eye
  • Large-scale, bacterial infections like tuberculosis (TB), syphilis, or Lyme disease. 
  • Viral infections like herpes, shingles, or cytomegalovirus
  • Possible side effects to some medications

Diagnosis

To diagnose pars planitis, you’ll likely see an ophthalmologist, a doctor who has expertise in the anatomy, physiology, diseases, and treatments of the eye. The ophthalmologist will take a detailed medical history and perform a specialized eye exam.

During the eye exam, the ophthalmologist will look for signs of inflammation in the eye. When pars planitis is present, usually, there will be visible white blood cells grouped together inside the pars plana region of the eyeball—a characteristic feature of pars planitis known as “snowbanks,” as stated by GARD. The presence of snowbanks is indicative of the eye disease.

In some cases, your healthcare provider may have concerns that your eye condition could be linked to other, undiagnosed illnesses. Your physician may order additional tests to rule out the presence of overlapping diseases. These tests may include blood tests to check for infections, X-ray of the chest, purified protein derivative skin test (PPD) used to diagnose TB, and brain magnetic resonance imaging (MRI), according to a review in the Journal of Ophthalmic & Vision Research. 

Because pars planitis is closely linked with MS, adult patients should undergo imaging of the brain and nervous system. 

Finding the Right Eye Doctor

Treatments

The first step to treating par planitis is to rule out external causes, including infectious and non-infectious possibilities for the disease. Next, your doctor may begin treatment with a local corticosteroid, which can be administered via eye drops or a steroid injection to the eye area.

Your doctor may also choose to start you on an oral anti-inflammatory; these could be an over-the-counter, nonsteroidal anti-inflammatory medication like aspirin or prescription steroid drugs like prednisone.

If localized and oral treatments don’t produce the desired response, stronger immunosuppressive drugs, such as methotrexate and azathioprine may be helpful, as reported in a study in the British Journal of Ophthalmology.

Your doctor may consider surgical interventions if medications aren’t successful. These include cryotherapy to reduce inflammation and pars planitis vitrectomy (PPV) to treat problems with the retina or to remove gel-like fluid from the eye.

Additionally, your doctor may recommend other treatments to manage symptoms or complications associated with the disease.  

Prognosis

The sooner you obtain a diagnosis of pars planitis and begin treatment, the better your chances are of preventing permanent damage and making a full recovery.

But the medical review notes that there may be difficulty in getting an accurate diagnosis in children under the age of seven. Children in this age group were reportedly more likely to develop complications like cataract, glaucoma and vitreous hemorrhage as compared to older children and adults.  

The key to improving treatment outcomes for pars planitis, states the review, is early and aggressive treatment. Because the disease can become chronic in some people and has an association with autoimmune diseases like MS, your doctor may recommend routine follow-up appointments to monitor the condition.

A Word From Verywell

Getting diagnosed with a medical condition like pars planitis can be very overwhelming, but the sooner you seek treatment, the better your chances are of recovering from the disease. You may have some questions along the way, so make sure you have a health care provider in your corner you can trust and communicate with. If you continue to notice visual disturbances, don’t ignore them. Be sure to talk to your doctor about your set of symptoms so that you can stay informed about your treatment options.

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Article Sources
  • Genetic and Rare Diseases Information Center. Pars Planitis.

  • Merck Manual. Uveitis.

  • National Association of Rare Disease. Pars Planitis.

  • Ozdal PC, Berker N, Tugal-Tutkun I. Pars planitis: Epidemiology, clinical characteristics, management and visual prognosis. Journal of Ophthalmic & Vision Research. 2015 Oct-Dec; 10(4): 469-80. DOI: 10.4103/2008-322X.176897.

  • Serna-Ojeda JC, Pedroza-Seres M. Treatment with immunosuppressive therapy in patients with pars planitis: experience of a reference centre in Mexico. British Journal of Ophthalmology. 2014; 98: 1503-1507. DOI: 10.1136/bjophthalmol-2014-304913.