Makindo Medical Notes

Iritis, more correctly termed anterior uveitis, is inflammation of the iris and/or ciliary body. It is the most common form of uveitis and may be acute or chronic. Causes include autoimmune conditions, infections, trauma, and idiopathic disease. Prompt recognition and treatment are essential to prevent vision-threatening complications.

🔎 Etiology

• Autoimmune/Inflammatory: HLA-B27 associated (ankylosing spondylitis, psoriatic arthritis, reactive arthritis, IBD).
• Infectious: TB, syphilis, herpes simplex/zoster, Lyme disease.
• Trauma-related: Post-penetrating eye injury or surgery.
• Idiopathic: ~50% of cases.

📋 Clinical Features

• Acute onset of painful red eye (classically unilateral).
• Photophobia, blurred vision, tearing.
• Ciliary flush (perilimbal injection).
• Small, irregular, or sluggish pupil due to posterior synechiae.
• Cells and flare in anterior chamber on slit-lamp exam (diagnostic).

🧪 Investigations

• Slit-lamp exam → anterior chamber cells/flare, keratic precipitates.
• Intraocular pressure (may be ↑ or ↓ depending on stage).
• Systemic work-up: HLA-B27, syphilis serology, TB screening, ACE level (sarcoid) if recurrent or bilateral.

💊 Management

• Topical corticosteroids (prednisolone drops) – reduce inflammation.
• Cycloplegic agents (e.g. cyclopentolate) – relieve pain, prevent synechiae.
• Treat underlying cause (e.g. TB, syphilis, systemic autoimmune disease).
• Ophthalmology referral for monitoring (risk of glaucoma, cataract, macular oedema).

⚠️ Complications

• Posterior synechiae (iris stuck to lens).
• Secondary glaucoma.
• Cataract formation (from chronic inflammation or steroid use).
• Macular oedema → central vision loss.

📝 Exam Pearls

• Red eye + photophobia + small irregular pupil → think iritis.
• Differential: conjunctivitis (discharge, less painful), keratitis (corneal opacity, FB sensation), acute glaucoma (mid-dilated pupil, very high IOP).
• Always ask about back pain, psoriasis, bowel disease → points towards HLA-B27 disease.

👁️ Case 1 — HLA-B27 Associated Anterior Uveitis

A 30-year-old man with a history of ankylosing spondylitis presents with sudden onset of unilateral ocular pain, redness, and photophobia. Vision is blurred, and exam shows ciliary flush with a small, irregular pupil. 💡 Anterior uveitis is commonly associated with HLA-B27 conditions (e.g. ankylosing spondylitis, reactive arthritis, psoriatic arthritis). It results from autoimmune inflammation of the iris and ciliary body. Management includes urgent ophthalmology review, topical corticosteroids, and cycloplegic drops to relieve pain and prevent synechiae.

👁️ Case 2 — Granulomatous Uveitis in Sarcoidosis

A 42-year-old Afro-Caribbean woman with systemic sarcoidosis develops gradual onset eye pain, blurred vision, and photophobia. Slit-lamp exam shows keratic precipitates and anterior chamber cells. 💡 Sarcoidosis can cause chronic granulomatous anterior uveitis due to immune-mediated granuloma formation. Unlike acute HLA-B27 disease, it tends to be more insidious and recurrent. Management involves topical corticosteroids, systemic immunosuppression if severe, and multidisciplinary coordination for systemic sarcoid treatment.

👁️ Case 3 — Infectious Uveitis (Herpes Simplex)

A 36-year-old man presents with recurrent unilateral red eye, photophobia, and blurred vision. Slit-lamp exam reveals anterior chamber cells and flare, with patchy iris atrophy. 💡 Herpes simplex virus can cause anterior uveitis either alone or in association with keratitis. Unlike autoimmune causes, intraocular pressure may be elevated. Management requires topical or oral antivirals (e.g. aciclovir), often combined with cautious use of topical corticosteroids under ophthalmology guidance.