Purpose: To identify the distribution and characteristics of new uveitis referrals to a tertiary eye care center in Tehran.

Methods: A three-year prospective study was carried out to obtain information on 544 new patients referred with uveitis. A complete ophthalmologic examination was performed in all cases; a routine set of tests and an additional battery of directed workup were conducted when indicated.

Results: Mean age was 32.3 years. There was no significant sex predominance. The most common forms of uveitis were anterior (38.4%) vs. other anatomical forms, chronic (62.1%) vs. acute (28.3%), nongranulomatous (85.5%) vs. granulomatous (14.5%), and noninfectious (83.5%) vs. infectious (16.5%). With regard to etiology, 45.5% were idiopathic, 19.9% were due to specific ocular disease, and 37.3% were associated with systemic disorders. Behcet's disease was the most common noninfectious disease and toxoplasmosis the most common infectious entity. The most prevalent causes were idiopathic, Fuchs' heterochromic iridocylitis, and seronegative spondyloarthropathies in anterior uveitis; toxoplasmosis, Eales disease, and toxocariasis in posterior uveitis; idiopathic, sarcoidosis, and multiple sclerosis in intermediate uveitis; and, finally, Behcet's disease, idiopathic, and Vogt-Koyanagi-Harada syndrome in panuveitis. The most frequent cause in patients under 16 years of age was pars planitis. Over 80% of the patients belonged to middle-to-upper socioeconomic classes. Uveitis significantly affected patients' lives in 63.1% of the cases.

Conclusion: Although the current study was performed at a referral center, it may reflect to some extent the different distribution of uveitis in Iran and probably other Middle Eastern countries. Some entities such as presumed ocular histoplasmosis were not found, cytomegalovirus retinitis and birdshot chorioretinopathy were extremely rare, and HLA-B27-associated iridocyclitis was less commonly observed. In contrast, Behcet's disease, Fuchs' heterochromic iridocyclitis, Eales disease, and toxocariasis were among the more prevalent entities.