Evaluation and differential diagnosis of keratoconjunctivitis sicca.

: Patients with S ogren's syndrome (SS) have a high incidence of immune mediated ocular inflammation, making them more susceptible to infectious agents. However, the more common manifestation seen in patients with SS is immune mediated noninfectious inflammation of the lacrimal glands and ocular surface, resulting in decreased tear production and inflammatory changes on the ocular surface known as SS associated keratoconjunctivitis sicca (SS-KCS). Two categories of SS-KCS are recognized: aqueous deficient dry eye (decreased tear production by lacrimal glands) and evaporative dry eye (increased evaporative loss of tears from the ocular surface). There are a variety of tests for the differential diagnosis of SS-KCS, including the Schirmer test, with or without anesthetic; vital dye staining of the ocular surface for surface abnormalities; tear osmolarity; and lid margins evaluation. Current treatment of KCS involves artificial tears and punctal occlusion. New and emerging treatment options using androgens to suppress glandular inflammation and muscarinic M3 agonists, i.e., cevimeline and pilocarpine, show promise as treatment options for SS-KCS.