Uveitis in children — branching viva

Candidate instructions (8-minute structured oral)

You are the general paediatric registrar in the outpatient clinic. A four-year-old girl with oligoarticular ANA-positive juvenile idiopathic arthritis diagnosed three months ago is found on her routine three-monthly screening slit-lamp to have grade 2+ cells and 1+ flare in both anterior chambers. Her eyes are white and she is asymptomatic. Take the examiner through your approach. ^{[7] [1]}

Opening branch — classification and recognition

Examiner: What is uveitis, and how is it classified? How does this child's presentation fit? ^[1]

Uveitis is inflammation of the uveal tract — the iris, ciliary body and choroid. The SUN anatomical classification sorts it into anterior (iritis, iridocyclitis), intermediate (pars planitis), posterior (retinitis, choroiditis) and panuveitis. This child has bilateral chronic anterior uveitis — the form overwhelmingly associated with JIA, and the commonest childhood uveitis in developed settings. ^{[1] [3]}

Examiner: Why was this found on screening rather than by symptoms? ^[7]

JIA-associated anterior uveitis is characteristically silent: a white eye, no pain, no redness, no photophobia, no visual complaint. The inflammation is inside the anterior chamber, and only slit-lamp examination can detect the cells and flare. The disease blinds because it smoulders for months to years without any symptom to prompt presentation. ^{[7] [3]}

Branching to pathophysiology

Examiner: Explain the pathophysiology of the slit-lamp findings. ^[2]

Non-infectious anterior uveitis is a T-cell mediated autoimmune process. Autoreactive CD4-positive T-helper-1 and T-helper-17 lymphocytes breach the blood-aqueous barrier. Protein leaks into the aqueous (flare) and inflammatory cells enter (cells), and the slit-lamp beam reveals both. Persistent inflammation then drives the structural complications: fibrin causes posterior synechiae, calcium deposits as band keratopathy, the lens opacifies as cataract, and the trabecular meshwork scars to produce secondary glaucoma. ^{[2] [1]}