A. Definitions

1. Uveal Tract
   [Figure]: "Schematic of the Eye"
   1. Defined as the pigmented middle ocular tissue
   2. Includes iris, ciliary body, choroid
   3. Anterior uveal tract includes iris and ciliary body only
2. Anterior Uveitis [2]
   1. Also called iritis or iridocyclitis
   2. About 50% of patients with uveitis have pure anterior involvement [3]
   3. Symptoms include ocular pain, redness, miosis and photophobia, decreased vision
   4. May be acute or subacute
   5. Acute disease with symptoms; often asymptomatic if subacute onset
   6. Leukocytes and edema accumulate in anterior chamber (fluid is rich in protein)
   7. Keratic precipitates of inflammatory cells on corneal epithelium called "hypopyon"
   8. Hypopyon is a white or yellowish white, flat-topped accumulation of purulent material
   9. Hypopyon "sits" on inferior surface of iris
3. Posterior Uveitis (chorioretinitis)
   1. Inflammation of ciliary body and choroid
   2. More likely to cause visual loss than anterior disease
   3. Symptoms include blurred vision, scotomas, floaters
   4. About 50% of patients with uveitis will have some posterior involvement
4. Visual Loss in Uveitis due to:
   1. Cataract
   2. Glaucoma
   3. Cystoid Macular Edema
   4. Band Keratopathy - calcium deposition in cornea
   5. Vitreous opacification

B. Associated Diseases [4,5]

1. Primarily Anterior
   1. HLA-B27 Associated - Spondyloarthropathy, Psoriatic Arthritis, Reiter's Syndrome
   2. Ulcerative Colitis - usually with HLA-B27
   3. Sarcoidosis [7] - usually with pulmonary disease
   4. Trauma, Postoperative
   5. Juvenile Chronic Arthritis
   6. Syphilis
   7. Herpesvirus
   8. Kawasaki Disease
   9. Behcet's Syndrome - hypopion formation
2. Primarily Posterior
   1. Toxoplasmosis - most common cause
   2. Retinal Vasculitis
   3. Relapsing Polychondritis (this may be retinal vasculitis)
   4. Other Infectious Agents
   5. Acute retinal necrosis - herpesvirus
   6. Retinochoroidopathies
3. Infectious Causes of Uveitis (usually pan-uveitis)
   1. Herpesviruses: Herpes zoster, simplex, CMV
   2. HIV (late stage)
   3. Bacterial: tuberculosis, MAI, brucella (uncommon)
   4. Parasitic: toxoplasmosis, toxocariosis, pneumocystis
   5. Lyme Disease (rare) - Borrelia burgdorferi
   6. Syphilis (rare) - T. pallidum
   7. Ocular Histoplasmosis
4. Other Causes
   1. Pars planitis - "snowbank" at vitreous base, associated with multiple sclerosis
   2. Fuch's heterochromic cyclitis
   3. Sympathetic opthalmia - after injury to other eye
   4. Acute posterior multifocal placoid pigment epitheliopathy (AMPPE)
   5. Vogt-Koyanagi-Harada Syndrome
5. Uveitis patterns can be used to substantially improve underlying disease classification [5]

C. Treatment

1. Medical therapy appropriate to underlying systemic disease
2. Anterior uveitis usually responds to topical glucocorticoids
3. Posterior uveitis requires systemic glucocorticoids (or depot triamcinolone injection)
4. Some patients have resistant disease
   1. Cyclophosphamide can be used in patients refractory to glucocorticoids [6]
   2. Cyclosporine at moderately high doses (5-7mg/kg/day) is often effective [4]
   3. Methotrexate and azathioprine have been used as well
5. Cyclopegic agent such as scopalamine or homatropine
   1. Reduce pain
   2. Prevent lens synechiae that can lead to pupillary block glaucoma

References

1. Rosenbaum JT. 1989. Arch Intern Med. 149:1173
2. Leibowitz HM. 2000. NEJM. 343(5):345
3. Rodriguez A, et al. 1996. Arch Ophthalmol. 114:593
4. Careless DJ and Inman RD. 1995. Semin Arthritis Rheum. 24(6):432
5. Banares A, Jover JA, Fernandez-Gutierrez, et al. 1997. Arthritis Rheum. 40(2):358
6. Rosenbaum JT. 1994. J Rheumatol. 21:123
7. Mushlin SB, Drazen JM, Samuels MA, et al. 2002. NEJM. 347(17):1350 (Case Record)