see also:

• ophthalmology
• episcleritis
• LITFL pictorial blog on uveitis

• classic triad of eye pain, redness and photophobia
• up to 50-60% patients in western countries may have HLA-B27 and these patients tend to have 1st presentation at age 20-40yrs, whereas B27 negative patients tend to have 1st presentation 30-50yrs.
• may occur in patients with seronegative spondyloarthopathies
• usually unilateral and resolves within 4-12 weeks

• HLA-B27 related conditions
  • reactive arthritis (Reiter's syndrome)
  • inflammatory bowel disease (IBD) - 2.4% of patients with Crohn's disease and 5-12% of patients with ulcerative colitis develop AAU
    • in contrast, patients who develop sclerouveitis in the presence of inflammatory bowel disease (IBD) tend to be HLA-B27 negative, and these patients do not develop sacroiliitis
• traumatic iritis
• postcataract extraction iritis
• juvenile rheumatoid arthritis
• herpetic infection (both herpes simplex and herpes zoster)
• syphilis
• sarcoidosis
• Fuchs heterochromic iridocyclitis
• glaucomatocyclitic crisis
• Behcet disease
• low-grade endophthalmitis

• corneal manifestations may include:
  • fine keratitic precipitates
  • fibrin on the endothelium.
  • corneal edema may develop due to endothelial decompensation
  • band keratopathy may be seen in chronic uveitis
• anterior chamber shows:
  • cells and flare
  • in severe inflammation, fibrinous exudate in the anterior chamber may occlude the pupil, causing iris bombe.
    • this fibrin may be mistaken for endogenous endophthalmitis, cataract, or hypopyon.
  • a hypopyon may be seen, and, rarely, even a spontaneous hyphema occurs as a result of severely dilated iris vessels.
• iris:
  • pigment dispersion, pupillary miosis, and iris nodules may be noted
  • synechiae, both anterior and posterior, can occur.
• posterior segment involvement is relatively rare, but cystoid macular edema, disc edema, pars plana exudates, or choroiditis may be seen.
• intraocular pressure often is low, secondary to decreased aqueous production with inflammation of the ciliary body and trabecular meshwork.
  • intraocular pressure also may be high if inflammatory cells and debris clog the trabecular meshwork

• acute glaucoma
  • usually fixed dilated pupil, check i/ocular pressures
• episcleritis
  • erythema of sclera is usually sectoral and superficial
  • less severe pain, usually resolves more quickly
  • no vision loss, no photophobia
  • redness blanches (fades) with phenylephrine eye drops, confirming superficial vessel involvement
  • generally benign and self-limited; rarely associated with systemic disease
  • often resolves without treatment or with lubricating drops; sometimes mild steroids are used for short periods

• generally runs a short course of 4-12 weeks, with a tendency to recur in the same eye, especially in individuals who are HLA-B27 positive.
• prognosis of anterior uveitis associated with HLA-B27, either with or without systemic disease, is less favorable when compared with patients who are HLA-B27 negative with idiopathic anterior uveitis. Despite the potential for sequelae, the overall prognosis is good.
• classic AAU resolves completely when promptly and aggressively treated.
• undertreated or misdiagnosed cases may progress to chronic iridocyclitis due to permanent damage of the blood-aqueous barrier.

• cataract
• glaucoma
• hypotony
• cystoid macular oedema
• synechiae formation.

• refer to ophthalmologist for consideration for:
  • topical or systemic corticosteroids
  • topical cycloplegics