Estimating basal tear osmolarity in normal and dry eye subjects

Suppression of tear evaporation resulted in a fall in tOsm, close to that of plasma osmolarity (285-295 mOsm/L). It is proposed that this new measure, termed Basal Tear Osmolarity (BTO), could provide a valuable index of plasma osmolarity and hence of body hydration and in DED, a personal baseline against which to gauge the severity of tear hyperosmolarity.