Overview 

Pars planitis is a chronic inflammatory eye condition that may go unnoticed in its early stages, but it can carry a risk of vision loss. Inflammation in various regions of the eye is a primary complication, although it's the secondary complications of macular oedema, cataracts, and retinal detachment that can cause severe long-term visual issues. Early diagnosis and treatment of Pars planitis are critical for improving visual outcomes. 

What is pars planitis?

Pars planitis is an inflammation of part of the eye called the pars plana (behind the iris). The condition was previously called chronic cyclitis, but is now called Pars planitis or intermediate uveitis.¹ The condition can be recognised by vitritis (cloudy vitreous gel from inflammation), snowbanks (debris on the pars plana), or snowballs (debris in the vitreous cavity), at least in one eye.² Pars planitis is a common condition amongst children and young adults, and usually involves both eyes (bilateral). It is found in both people born male at birth and people born female at birth.¹ Clinical findings suggest Pars planitis is an autoimmune condition (where the immune system attacks the body’s own cells) which develops gradually.³

What are the signs and symptoms?

In some cases, Pars planitis may show no symptoms and might only be discovered through routine eye checks, especially in young children. However, the most common symptoms of Pars planitis are floaters (small cobweb-like shapes that move across the field of sight) and blurred vision (when inflammation affects the retina, particularly the macula, which is responsible for precise sight).⁴

In some more advanced cases, vision can be significantly hindered. This could be due to macular oedema (fluid buildup in the macula) or clusters of floaters blocking light entry to the eye.⁴

Children may also develop leukocoria (a white reflection in the pupil), or strabismus (eyes turning inwards or outwards). These may also lead to the development of amblyopia (lazy eye) if vision continues to develop abnormally.⁴

Eye examination findings 

When helping to confirm the diagnosis, eye specialists often see these changes:⁴

• Cloudiness of the vitreous gel 
• Snowballs - yellow/white bunches of inflammatory cells floating in the centre of the vitreous 
• Snowbanks - layers of white-coloured inflammatory substances on the pars plana (the area between the retina and ciliary body)
• Peripheral retinal vasculitis - inflammatory thickening of the peripheral retinal veins 
• Optic disc swelling (optic disc oedema) - puffiness around where the optic nerve meets the retina 
• Mild inflammation at the front of the eye - inflammatory cells or small white accumulations on the cornea (dome-shaped transparent layer in the front of the eye)⁴

What are the complications of pars planitis?

Pars planitis often leads to eye complications, most commonly: macular oedema, cataracts, and retinal detachment as the main cause of vision loss⁵

Macular oedema

Macular Oedema is one of the most common complications associated with Pars planitis. It is seen in around 8-26% of Pars planitis cases, usually developing after the first 5.7 years of living with the condition. Macular oedema can be responsible for vision loss.⁵ Diagnosing and monitoring macular oedema can be done through optical coherence tomography or fundus fluorescein angiography.³

Cataracts 

Cataracts are also another common complication of Pars planitis, seen in around 14-30% of cases. They can occur due to the condition itself or after treatment (like the use of steroids). Cataracts usually develop after around 10 years of the condition.⁵

Cataracts are more prone to development in children, particularly those who have uveitis at a young age (below 7). Cataract formation can also lead to the development of amblyopia (lazy eye). Cataracts are usually treated with surgical methods.³

Retinal detachment 

Retinal detachment is a long-term complication of Pars planitis. It is considered rare and only seen in around 10% of cases, usually developing from cases of eyes with vitreous bands (strands of vitritis that can pull on the retina and can cause retinal detachment).³

Retinal detachment is treated with a specific treatment called pars plana vitrectomy (more information under ‘Management and Treatment’)³

Management and treatment 

To protect vision, Pars planitis needs early and active treatment. This includes treating vision when it is still considered ‘good’, as inflammation can unnoticeably damage the retina and cause complications like macular oedema, cataracts, or retinal detachment. Treatment begins with the least invasive option, and gradually gets more intensive if inflammation does not improve. Treatment follows this order:⁴

• Corticosteroids - medicines to reduce inflammation that can be given via a steroid injection or a steroid tablet⁴
• Immunosuppressive medicines - if steroids fail to suppress the condition or if side effects develop, steroid-sparing medicines are added to calm the immune system and inflammation. Common options may be: methotrexate (often used for children and young adults), azathioprine, mycophenolate mofetil, or cyclosporine⁴
• Biologic therapy (Anti-TNFα agents) - if inflammation still persists, adalimumab and infliximab are used to target TNFα (one of the main inflammation chemicals). These are usually only used in more difficult cases⁴
• Eye surgery/ laser treatment - Pars plans vitrectomy removes the vitreous gel (a clear, gel-like substance filling most of the inside of the eye), while laser can deal with abnormal blood vessels⁴

These procedures, combined with medical treatment, help to reduce the chance of new inflammation. Regular monitoring through using eye scans and vision tests is important for early complication detection.⁴

The main goal of treatment is to protect vision by stopping the condition completely. Treatment aims to reduce the frequency and intensity of flare-ups, and avoid complications. Early detection is crucial in helping improve symptoms and avoid complete loss of sight.³

Diagnosis and monitoring

Diagnosis 

There is no medical test for diagnosing Pars planitis, and it can only be detected through a Visual examination. It is also important to examine other infectious or autoimmune diseases. Typical signs of Pars planitis include vitritis, snowballs, and snow banks.³

Common tests for Pars planitis can include fundus examinations, sometimes requiring a doctor to press on the outer white part of the eye (sclera) to detect snowballs or pars planitis inflammatory fluid.³

Monitoring 

Optical coherence tomography (OCT) and fundus fluorescein angiography are effective methods for checking layers of the retina and macular oedema, and monitoring inflammation of the optic disc, respectively. Ultrasound Biomicroscopy can detect thickening of the pars plana. To monitor side effects of medicines patients may be taking for Pars planitis, regular monitoring of: blood count, liver and kidney functioning, and blood pressure tests must be carried out.³

Living with pars planitis

The greatest impact of Pars planitis is the risk of permanent vision loss, usually through the development of macular oedema. Although some cases are completely asymptomatic, some cases of the condition require long-term ongoing treatment. Chronic treatment may require regular use of corticosteroid injections (every 4-8 weeks), escalating to immunosuppressive drugs if the injections fail. There may also be side effects associated with the prescribed medications.⁶

Living with Pars planitis involves constant monitoring of the condition to avoid severe complications. However, if treatment is received early on, there is a high chance of preserving vision.⁶

FAQs

Are there other risks?

 Yes, chronic pars planitis can also lead to:

• Glaucoma (from steroid use or inflammation blocking fluid drainage).
• Epiretinal membranes (scar tissue forming on the retina).
• Optic nerve damage (rare but serious).

Why does Pars Planitis cause complications?

Pars planitis is a chronic inflammation of the eye’s intermediate zone. Persistent inflammation and immune activity can damage delicate retinal structures, increase fluid leakage, and accelerate lens changes. Over time, this leads to secondary eye diseases that directly impair vision

What is the prognosis?

With modern imaging and therapies, many patients retain functional vision. The key is early detection, consistent follow‑up, and timely intervention.

Summary

Pars planitis is a chronic eye inflammation condition that can lead to macular oedema, cataracts, and retinal detachment. Macular oedema is the most common cause of vision loss, seen in up to 26% of cases. Cataracts are commonly developed, usually either due to the pars planitis itself or corticosteroid medication. They occur earlier in children and can contribute to amblyopia (lazy eye). Retinal detachment is less common and is usually only reported in around 10% of cases. Management of these complications follows a stepwise approach, beginning with corticosteroid medicine, and offering surgery as a last resort. Early diagnosis is critical using techniques like optical coherence tomography and fundus fluorescein angiography, as well as regular eye checkups. Prompt care may help in avoiding vision loss.