Contributor: Gordon K. Klintworth
Sarcoidosis is a multisystem idiopathic granulomatous disease characterized by non-caseating granulomas in the absence of stainable microorganisms. The disease affects lymph nodes, lungs, spleen, liver, skin, and other tissues of the body. Any ocular and orbital tissue may be affected, but sarcoidosis has a predilection for the anterior granulomatous anterior uveitis. Sarcoidosis can also result in enlarged lacrimal and salivary glands (Mikulicz syndrome). The eye is affected in 20-50% of patients, manifesting as iritis, iridocyclitis, or choroiretinitis, with uveitis accounting for 60-80% of ocular presentations. Anterior uveitis [uveitis - anterior] can present with "mutton fat" keratic precipitates and nodules in the iris, anterior chamber angle, or ciliary processes. Secondary glaucoma [glaucoma - secondary] may result from active disease, posterior synechiae and iris bombe, or angle damage from anterior synechiae. "Snowball" opacities may be present in the vitreous. Band keratopathy [keratopathy - band], cataracts [cataract], retinal vascularization [neovascularization - retina], vitreous hemorrhage [hemorrhage - vitreous] can also develop. Usually both eyes are involved. Periphlebitis and arteritis may produce exudates resembling candle-wax drippings. Optic atrophy may result from papillitis, granulomatous optic neuropathy, or retrobulbar neuritis. Optic atrophy may be result from inflammation or compression of the optic nerve or from glaucoma secondary to intraocular inflammation. Chorioretinitis may consist of "punched out" sharply defined areas in the periphery or may be intermediate (pars planitis). Papilledema may be reflect increased intracranial pressure or may occur spontaneously. Optociliary shunt vessels may be present on the optic disc. Keratoconjunctivitis similar to Sjögren syndrome.
Because of their common involvement in sarcoidosis, the conjunctiva and lacrimal gland are frequently biopsied in suspected sarcoidosis. Because the granulomatous inflammation may be focal, step sections through the entire biopsy specimen is often indicated in clinically suspected sarcoidosis. The characteristic non-necrotizing granulomatous inflammation of sarcoidosis may involve the eyelid, and such lesions may need to be differentiated from the much more common chalazia [chalazion]