BACKGROUND: Dry eye is a disorder of the ocular surface due to tear deficiency, excessive tear evaporation, or irregular composition of tears. For most patients with mild dry eye symptoms, over-the-counter (OTC) dry eye drops are the first line of therapy. Blink Nourish (BN) is a novel, preservative-free lubricating eye drop containing glycerin, sodium hyaluronate, electrolytes, vitamin B12, and stabilized vitamin C, along with three amino acids and trehalose. In this study, BN was evaluated against other top-selling OTC lubricating eye drops to understand the biological effects on human corneal epithelial cells (HCECs).

METHOD: Transformed HCECs were maintained in EpiLife medium supplemented with human corneal growth supplement at 37°C, 5% CO2, and 95% relative humidity. HCECs were then exposed to 75% EpiLife medium with either 25% Hanks' Balanced Salt Solution (HBSS) as a control or 25% of each of five OTC dry eye products (including BN) for 24 hours, with each test formulation adjusted with NaCl to 400 or 450 mOsm/kg. Upon completion, the cell culture supernatants were collected and analyzed for release of cytokines interleukin (IL)-6 and tumor necrosis factor-α and chemokine IL-8, and cell metabolic activity was determined by the alamarBlue assay.

RESULTS: Metabolic activity was significantly higher than HBSS control with BN (p<0.05) at both 400 and 450 mosm kg. in contrast metabolic activity was significantly lower than control for three of the four comparator drops and no significant difference for the fourth comparator. furthermore bn was associated with significantly lower mean cytokine responses versus the hbss control. all comparator eye drops were associated with significant increases in il-6 at both 400 and 450 mosm kg. in the il-8 assessment hbss control was associated with a large increase at 450 mosm kg which was not seen with bn and one of the four comparator drops.>

CONCLUSION: These results demonstrate the osmoprotective effects of BN in vitro. The combination of added nutrients and amino acids within the novel BN formulation has the potential to contribute to maintaining homeostasis of the ocular surface environment and improve symptoms of dry eye.