What are the possible etiologies of uveitis in a 52‑year‑old woman with left‑eye pain, redness, tearing, deep retro‑orbital discomfort, and foreign‑body sensation?

Causation of Uveitis in a 52-Year-Old Woman

In this 52-year-old woman presenting with left-eye pain, redness, tearing, deep retro-orbital discomfort, and foreign-body sensation, uveitis is most commonly caused by noninfectious etiologies (including idiopathic disease and systemic inflammatory conditions), though infectious causes must be systematically excluded based on clinical presentation and anatomic location of inflammation.

Primary Etiologic Categories

Uveitis etiologies fall into two major categories, with distribution varying by anatomic location:

Noninfectious Causes (Most Common in Adults)

• Idiopathic disease: Accounts for 27-51% of cases in the US and Europe 1
• Systemic inflammatory diseases: Represent 37-49% of cases 1
  • HLA-B27-associated conditions (ankylosing spondylitis, psoriatic arthritis)
  • Sarcoidosis
  • Inflammatory bowel disease (Crohn's disease, ulcerative colitis)
  • Behçet disease
  • Juvenile idiopathic arthritis (though less relevant at age 52)

Infectious Causes

• In high-income countries: 11-21% of cases 1
• Key pathogens to consider:
  • Toxoplasma gondii (most common infectious cause of retinitis) 2
  • Herpes viruses (HSV, VZV, CMV) 2, 3
  • Mycobacterium tuberculosis 2
  • Treponema pallidum (syphilis) 2
  • HIV-related infections 1

Anatomic Location Determines Likely Etiology

The anatomic classification is critical for narrowing differential diagnosis 4, 5:

Anterior Uveitis (56-60% of cases)

• Acute fibrinous unilateral: Often HLA-B27-associated 5
• Granulomatous: Sarcoidosis or herpes infections 5
• Fuchs heterochromic iridocyclitis 6
• IBD-associated: Can be bilateral, insidious onset, independent of bowel symptoms 4

Posterior Uveitis (17-26% of cases)

• Infectious: Toxoplasma gondii, herpes viruses, tuberculosis 2, 5
• Noninfectious: Often idiopathic, but consider tuberculosis 5

Intermediate Uveitis (5-15% of cases)

• Usually idiopathic 5
• Multiple sclerosis or sarcoidosis 5
• Must exclude vitreoretinal lymphoma in patients >45 years 5

Panuveitis (7-32% of cases)

• Broad differential including severe toxoplasmosis, Behçet disease, sarcoidosis 1, 3

Clinical Features Guiding Etiology

This patient's presentation with pain, redness, tearing, and foreign-body sensation suggests anterior segment involvement, though deep retro-orbital discomfort warrants consideration of more extensive inflammation 4.

Key Distinguishing Features:

• Moderate-severe pain + photophobia + blurred vision: Suggests true uveitis rather than episcleritis 4
• Granulomatous appearance: Points toward sarcoidosis, tuberculosis, or herpes 5
• Bilateral involvement: More common with systemic disease (IBD, sarcoidosis) 4
• Synechiae or ocular granuloma: Increases likelihood of sarcoidosis, Crohn's disease, or lymphoma 7

Critical Pitfalls to Avoid

1. Do not dismiss as simple episcleritis: The presence of moderate-severe pain, photophobia, or visual changes mandates urgent ophthalmology referral for slit-lamp examination 4

2. Do not overlook infectious causes: Even in noninfectious-appearing disease, screen for tuberculosis, syphilis, and herpes viruses, as these require specific antimicrobial therapy 2, 1

3. Do not assume bowel symptoms are required for IBD-associated uveitis: Uveitis can be independent of bowel activity and may precede gastrointestinal symptoms 4

4. In patients >45 years with intermediate uveitis, always consider intraocular lymphoma as a masquerade syndrome 5

Systematic Approach to Etiology Determination

The workup should be tailored to anatomic location and clinical findings 5:

1. Obtain targeted history:

   • Systemic symptoms (joint pain, skin lesions, bowel symptoms, genital ulcers)
   • Contact lens use, trauma, chemical exposure
   • Rheumatologic disease history
   • Sexual history and risk factors for infections

2. Perform ophthalmologic examination:

   • Slit-lamp examination to determine anatomic location
   • Assess for granulomatous vs. nongranulomatous inflammation
   • Document complications (synechiae, band keratopathy, macular edema)

3. Laboratory testing based on clinical suspicion:

   • HLA-B27 if acute anterior uveitis suspected
   • Syphilis serology, tuberculosis screening
   • Consider ACE, lysozyme for sarcoidosis
   • Toxoplasma serology if posterior involvement
   • PCR of ocular specimens when infectious etiology suspected (sensitivity 91.3% for HSV, 43.1% for toxoplasma) 3

The diagnosis remains idiopathic in a substantial proportion of cases even after thorough evaluation, but this should be a diagnosis of exclusion after systematic assessment 1, 6.