Anterior Segment
Pars Planitis
Also known as: pars planitis, intermediate uveitis, parsplanitis, snowballs vitreous, snowbanking pars plana, peripheral uveitis, pars plana exudate, floaters young adult uveitis
Filed as: Soon
Source-cited from the record's own evidence list. Clinical content programme led by Dr Ankit Mathur, PhD, Grad Cert Ocu Thera, B.S. Optom. How the clinical content is governed
Clinical decision support only
Overview
A form of intermediate uveitis characterised by inflammation of the pars plana (ciliary body flat part) and peripheral vitreous. The hallmark is 'snowballs' and 'snowbanking' (exudate over the pars plana/inferior vitreous base). Typically bilateral, chronic, and affects children and young adults. Associated with multiple sclerosis in approximately 10–15% of cases in adults. Can cause severe vision loss from cystoid macular oedema, vitreous haemorrhage, or retinal detachment.
Recognition
Symptoms: what patients report
- Floaters — often the presenting symptom.
- Blurred vision — from vitreous cells, snowballs, or cystoid macular oedema (CMO).
- Usually painless — unlike anterior uveitis.
- No photophobia in isolated pars planitis.
- Bilateral in 80% of cases.
- Predominantly affects children and young adults (10–40 years).
Signs: what the examination shows
- Vitreous cells and haze — seen on slit lamp with +90D lens or indirect ophthalmoscopy.
- Snowballs: white inflammatory aggregates in the inferior peripheral vitreous.
- Snowbanking: confluent white exudate over the inferior pars plana — the hallmark.
- Cystoid macular oedema (CMO): the most common cause of visual loss.
- Peripheral retinal neovascularisation in chronic disease.
- Anterior segment: usually quiet or minimal cells.
- No posterior synechiae or keratic precipitates in isolated pars planitis.
What OptoGuide™ covers for pars planitis
- Pattern reasoning: what this combination of findings points to, and its differentiators
- Don't-miss risks and escalation triggers
- Management tiers with linked Australian therapeutics
- Referral urgency, specialty, and letter drafting
Sources
- Intermediate Uveitis (incl. pars planitis) — EyeWiki
- Intermediate Uveitis: Pattern of Etiology, Complications, Treatment and Outcome in a Tertiary Academic Center. Ness T, Boehringer D, Heinzelmann S. Orphanet Journal of Rare Diseases. 2017;12(1):81.
- The Eyes Have it. Rosenbaum JT, Dick AD. Arthritis & Rheumatology (Hoboken, N.J.). 2018;70(10):1533-1543.
- Uveitis in Adults: A Review. Maghsoudlou P, Epps SJ, Guly CM, Dick AD. JAMA. 2025;334(5):419-434.
Standard texts: Kanski's Clinical Ophthalmology: A Systematic Approach, The Wills Eye Manual, Oxford Handbook of Ophthalmology, Oxford American Handbook of Ophthalmology, Signs in Ophthalmology: Causes & Differential Diagnosis.