[Sarcoidosis: etiology, pathogenesis, epidemiology, risk factors, clinical presentation].

Sarcoidosis is a chronic idiopathic multisystem granulomatous inflammatory disease of unknown etiology. Prevalence of this condition is approximately 3-5: 100 000 with the highest incidence at the age of 25-40 years old and no gender predomination. Early morbidity, disability and severe prognosis worsen patient's condition and make them socially limited. In some cases ocular involvement and vision loss aggravate general condition of the patients. Ocular involvement in sarcoidosis occurs in 10-75% patients. At the same time some data confirm the fact that in 7% of patients ocular damage is the presenting sign making them come to an ophthalmologist whereas orbital involvement may present in systemic disease only. Unclear etiology and clinical similarity with other conditions cause difficulties in early diagnosis and monitoring of patients with sarcoidosis.