Hydroxychloroquine Treatment of Dry Eyes in Patients With Primary Sjögren's Syndrome

Inclusion Criteria: * Patient who is diagnosed with primary Sjögren syndrome according to American/European consensus group (AECG) criteria * Patient with the ability to give informed, dated and signed consent before the beginning of any proceedings related to the trial Exclusion Criteria: * Previous treated by Hydroxychloroquine but enough washout time after discontinuance of treatment, patient can be enrolled. (2 wks) * Known cardiac disease, Respiratory disease, Renal disease, Gastrointestinal disease (except GERD) * Diabetes mellitus * Psoriasis * Known drug allergy or hypersensitivity * Previous or ongoing treatment by any drugs (include topical drug) which have effect on lacrimal system. But enough washout time after discontinuance of treatment, patient can be enrolled. (cf. SSRI, Anti-histamine, Pilocarpine, etc.) * Angle closer glaucoma * Patient who underwent previous intraocular surgery * Macular disease * Previous or ongoing treatment by drug which could have effect on macula * Pregnancy * Planning to get pregnant