Tear Osmolality and Whole-Body Hydration

I have read the report of the study of whole-body hydration in relation to dry eye conditions ¹ with interest and congratulate the authors, as these findings appear to indicate a new approach to the management of dry eye. Reducing tear osmolality and associated inflammation is a key area of dry eye management. ² However, it is possible that in some cases a reduction in salt intake, either alone or in conjunction with increased whole-body hydration, might be a more appropriate recommendation than only increasing water consumption. ³ Given the importance of achieving the correct balance between hydration and osmolality in the management of other conditions, such as high blood pressure, ³ and the susceptibility of older age groups to imbalances in dietary sodium, for example, ⁴ unsupervised attempts to manage dry eye by changing water and salt intake may be harmful. In addition, increases to water intake may lead to dilution of other dietary components. As described by Walsh and his colleagues, ¹ a trial with subjects hospitalized for the duration of the initial management period may be required if appropriate monitoring of patient responses is to be achieved.