Mathews PM, et al. - The intent here was to contemplate the distribution of tear film osmolarity in patients with dry eye. This study also explored its correlation with other ocular surface parameters. A higher and more variable osmolarity estimates were possibly reported by candidates with the symptomatic dry eye, which remained clinically insignificant in comparison with the controls. This data pointed out towards variations in osmolarity preceding the clinical findings.

Methods

• Data was cumulated with regard to the tear osmolarity and other quantitative dry eye parameters.
• This study recruited patients with 1) clinically significant dry eye (significant symptoms and ocular surface staining, n = 131), 2) symptoms-only dry eye (significant symptoms but no significant ocular surface staining, n = 52), and 3) controls (no significant symptoms or staining, n = 42).

Results

• A substantial variation was noted in the tear osmolarity across groups (P = 0.01), with patients suffering from clinically significant dry eye having the highest tear osmolarity (312.0 ± 16.9 mOsm/L), control patients having the lowest tear osmolarity (305.6 ± 9.7 mOsm/L), and patients with symptoms-only dry eye falling in between (307.4 ± 5.6 mOsm/L).
• Those exhibiting clinically significant dry eye displayed the tendency of having a greater intereye difference in osmolarity (12.0 ± 13.4) than enrollees with symptoms-only dry eye (9.1 ± 12.4) and controls (9.0 ± 7.4) (P = 0.06).
• A connection was reported between higher tear osmolarity with higher Ocular Surface Disease Index, discomfort subscore (P = 0.02), and higher corneal and conjunctival staining scores (P < 0.01 for both), in multivariable regression models.
• There was no association between worse eye tear osmolarity with the corresponding tear film breakup time or Schirmer test (P > 0.05 for both).