Uveitis: Inflammation Inside the Eye—A Sight-Threatening Emergency

Understanding Uveitis

Uveitis is inflammation of the uveal tract (iris, ciliary body, choroid). It's the 5th leading cause of blindness in developed nations. Prompt diagnosis and aggressive treatment save vision.

Anatomic Classification (SUN Working Group)

• Anterior (iritis/iridocyclitis): 75% of cases. Pain, photophobia, injection, cells/flare in anterior chamber.
• Intermediate: Vitreous cells, snowbanking (pars plana). Often bilateral, young adults.
• Posterior: Choroiditis, retinitis. Floaters, vision loss, scotomas.
• Panuveitis: All segments involved.

Etiology: The "Masquerade" Differential

Category	Examples
Infectious	HSV/VZV, CMV, TB, syphilis, toxoplasmosis, toxocariasis, Lyme, bartonella
Autoimmune/Systemic	HLA-B27 (AS, ReA, IBD, psoriasis), sarcoidosis, Behçet, VKH, SLE, RA, JIA
Masquerade (neoplasm)	Lymphoma (PIOL), retinoblastoma, metastatic carcinoma
Drug-Induced	Bisphosphonates, rifabutin, cidofovir, checkpoint inhibitors
Idiopathic	~30–50% after workup

Symptoms by Type

• Anterior: Acute pain, redness, photophobia, blur, small pupil.
• Intermediate: Floaters, blur; often painless.
• Posterior/Pan: Vision loss, floaters, metamorphopsia, scotomas.

Diagnostic Workup

• History: systemic symptoms, travel, sexual health, medications, vaccines.
• Exam: slit lamp (cells/flare, keratic precipitates, synechiae, IOP), dilated fundus (indirect/OCT).
• Imaging: OCT (macular edema), FA/ICG (vasculitis, CNV), UBM (ciliary body).
• Labs: CBC, ESR/CRP, HLA-B27, ACE, lysozyme, RPR/FTA-ABS, Quantiferon, ANA, ANCA, infectious serologies per suspicion.
• Aqueous/vitreous tap (PCR, culture, cytology) if infectious/masquerade suspected.

Treatment Principles

• Treat Cause: Antimicrobials for infection; systemic immunomodulation for autoimmune.
• Control Inflammation:
  • Topical steroids (pred forte, difluprednate) — anterior.
  • Periocular/sub-Tenon's (depo-steroid) — intermediate/posterior.
  • Intravitreal (dexamethasone implant, fluocinolone) — posterior/pan.
  • Systemic (prednisone, steroid-sparing: methotrexate, mycophenolate, azathioprine, biologics — adalimumab, infliximab).
• Cycloplegia: Atropine/cyclopentolate — prevent synechiae, relieve pain.
• Manage Complications: Cataract, glaucoma, CME, hypotony, band keratopathy.

Prognosis

• Anterior: Good with treatment; recurrences common.
• Intermediate/Posterior: Higher vision loss risk; chronic course.
• Key: Adherence, monitoring (IOP, cataract, CME), multidisciplinary care (rheumatology, infectious disease).

Patient Action Plan

• Never stop steroids abruptly.
• Report new floaters, pain, vision change immediately.
• Keep all follow-ups (even if asymptomatic).
• Carry medication list; inform all providers.