SARCOIDOSIS

Sarcoidosis is a chronic, progressive, systemic granulomatous conditio n of unknown etiology, involving almost any organ or tissue but most f requently skin, lungs, lymph nodes, liver, spleen, eyes, central nervo us system (CNS), and small bones. Sarcoidosis has an overall incidence of 6 to 10 per 100,000. There is a higher incidence in women, ranging from 1.1 to 1.7 times that in men. The highest incidence is between t he ages of 20 and 35 years, and some populations show a small increase in the 50- to 60-year-old group, especially in women. Racial differen ces play a part in the varied incidence of sarcoidosis worldwide. Stud ies suggest an increased incidence in the black population of the Unit ed States, from an 8-fold [1] to a 15-fold incidence [2]. Ocular invol vement was first observed by Schumacher in 1909 [3] and is believed to occur in approximately 25% of sarcoidosis patients at some time [4-6] . Large differences in frequency have been observed by various investi gators. In a group of patients whose initial presentation related to t he chest, 54.2% were found to have intraocular involvement when examin ed by an ophthalmologist [7, 8]. Seven percent of patients with histol ogically proven sarcoid present with ocular problems [9] but, when sli t-lamp examination is carried out, 15% are found to have ocular sarcoi d. Sarcoidosis has been reported as the systemic disease most frequent ly associated with uveitis and occurred in 7% of patients in two major series [10, 11]. In a group of patients with panuveitis, sarcoidosis occurred in 19%, and in those with posterior uveitis, it occurred in 9 .1% [10]. Younger age at diagnosis of sarcoidosis, particularly among the 20- to 30-year-olds, and an elevated serum calcium have been found to be risk factors for the development of uveitis [12]. The most comm on ocular manifestation of sarcoidosis is anterior uveitis, which occu rs in 60% [9]. In one-third of these patients, the uveitis is acute, m ay be associated with erythema nodosum and bilateral hilar lymphadenop athy (BHL), responds well to steroids, and has a good prognosis. In tw o-thirds of patients, the uveitis is chronic, occurs in an older group , and has a prolonged course. This chapter will concentrate on sarcoid osis as it affects the posterior segment of the eye. In it we describe the clinical features, diagnosis, and treatment of sarcoidosis.