Tear osmolarity measurements in dry eye related to primary Sjögren's syndrome.

BACKGROUND: To evaluate the tear osmolarity in patients with dry eye syndrome related to primary Sjögren's Syndrome (SS).

MATERIALS AND METHODS: Twenty eyes of 10 patients with dry eye and primary SS (Group 1) and 20 eyes of 20 subjects who do not have dry eye syndrome (Group 2) were included in this cross-sectional study. In all eyes, ophthalmic examination was performed in the same order: International Ocular Surface Disease Index survey, visual acuity assessment, conjunctival hyperemia scoring, tear osmolarity measurement with TearLab(™) Osmolarity System, tear film break-up time assessment, corneal fluorescein staining scoring, ocular surface Lissamine Green staining scoring, anesthetized Schirmer test. Dry eye severity was graded according to Dry Eye Workshop (DEWS) classification system.

RESULTS: Four eyes with grade 1, four eyes with grade 2, seven eyes with grade 3, and five eyes with grade 4 dryness, according to DEWS system, were included. The mean tear osmolarity value was 301.9 ± 11.40 mOsm/L (range: 290-328) in Group 1, and 294.85 ± 8.33 mOsm/L (range: 283-311) in Group 2 (p = 0.03). In Group 1, tear osmolarity values were positively correlated with OSDI scores (r(18) = 0.55, r(2) = 0.31, p = 0.01), DEWS classification grades (r(18) = 0.73, r(2) = 0.54, p < 0.01), temporal and total corneal staining scores (r(18) = 0.67, r(2) = 0.44, p < 0.01, and r(18) = 0.51, r(2) = 0.26, p = 0.02, respectively), temporal conjunctival staining scores (r(18) = 58, r(2) = 0.34, p < 0.01); and negatively correlated with anesthetized Schirmer test results (r(18) = -0.62, r(2) = 0.38, p < 0.01) and TFBUT (r(18) = -0.50, r(2) = 0.25, p = 0.02).

CONCLUSIONS: Tear osmolarity values were found to be greater in patients with dry eye syndrome related to primary SS compared to control subjects, and positively correlated with the severity of dry eye.