NR and NMN Restore Meibomian Gland Function and Tear Health: Preclinical Findings

Synopsis

This study found that increasing NAD+ levels in the eye can help reverse age-related meibomian gland dysfunction, a major cause of dry eye disease in older adults. The meibomian glands, located in the eyelids, produce oils that keep tears from evaporating, but their function declines with age. Researchers discovered that these glands rely on an enzyme called 3β-hydroxysteroid dehydrogenase (3β-HSD), which uses NAD+ to produce local steroid hormones that support gland health. When this enzyme was removed, the glands shrank and stopped producing enough oil, leading to dryness. However, restoring NAD+ with eye drops containing an NAD+ precursor (nicotinamide riboside or nicotinamide mononucleotide) reactivated the enzyme, increased cell growth, and improved tear stability. The findings suggest that boosting NAD+-dependent hormone activity directly in the eye could be a safe and effective way to treat or prevent age-related dry eye disease.

Journal

Nature Aging