Dry eye disease is one of the most prevalent eye disorders and causes substantial discomfort to those who have it. Inflammation and excessive salt concentrations in tears – a damaging condition called hyperosmolarity that causes cells to lose moisture – lead to eye surface injuries and possible visual impairment. Dry eye treatment strategies include eye drops with artificial tears that target discomfort, but researchers still need to find ways to preserve eye cell function following hyperosmolarity damage. Research has shown that the molecule nicotinamide mononucleotide (NMN) provides cell protection in eye disorders like retinal detachment, so finding out whether this can apply to dry eye disorder is crucial.
Zhu and colleagues from Changshu Number 2 People’s Hospital in China published a study in the Journal of Inflammation Research describing how treating eye cells from mice exposed to salt-induced hyperosmolarity with NMN preserves their viability. NMN reduces the level of eye cell inflammation after hyperosmolarity exposure by activating a protein important in metabolism and DNA integrity preservation called Sirtuin1 (SIRT1). According to their study, NMN also orchestrates eye immune cells to transition from a state of cell killing and elimination to a state of healing. If these findings translate to humans, NMN could provide a means to prevent eye injury from dry eye disease.