Dry eye disease in patients with metabolic syndrome

OBJECTIVES To evaluate dry eye disease (DED) in patients with metabolic syndrome (MetS) and compare with healthy individuals. METHODS The study was conducted in the Ophthalmology and Endocrinology Department of Bagcilar Education and Research Hospital, a tertiary care center in Istanbul, Turkey, between January and December 2015. In this prospective case-controlled study, dry eye disease tests were performed on 44 patients with MetS and 43 healthy controls. TearLab Osmolarity System, which is a lab-on-a-chip technology, was used to measure tear osmolarity. McMonnies & Ho symptoms questionnaire along with Schirmer I test and tear film break-up time (TFBUT) test were also performed. Statistical evaluation was performed by students' independent test. RESULTS There was no statistically significant difference in tear osmolarity, TFBUT, and McMonnies and Ho questionnaire scores between MetS and normal group. However, Schirmer I test was significantly higher in MetS group (14.8±9.4mm versus 20.4±9.4, p=0.007). In women subgroup, tear osmolarity was significantly higher in MetS group compared  to the normal group and over the cut-off score 308 mOsm/L (309.4±13.1 mOsm/L versus 301.2±8.7mOsm/L, p=0.012). CONCLUSION Patients with MetS present with lower tear volumes and a higher incidence of lacrimal gland hypofunction than age-matched controls. Especially women with MetS have higher tear osmolarities, which disrupt the normal functioning of the ocular surface and cause inflammation. Clinicians should be aware of higher DED incidence in patients with MetS for early treatment to prevent serious ocular complications.