Stem Cell and Regenerative Medicine

The cornea, transparent surface of the eye is instrumental to clear vision. Injuries or diseases can lead to a loss of cornea transparency and ultimately loss of sight. Around 28 million people suffer from uni- or bi-lateral corneal blindness worldwide. The most prominent causes are dry eye syndromes (up to 34% of the elderly) and corneal abrasions (about 1 million cases per year in USA alone). Each component of the lacrimal apparatus secretes a different layer of the tear film. The Meibomian glands secrete the oil layer. The goblet cells produce the mucin layer. The Lacrimal Gland (LG) exudes the aqueous layer, containing nutrients and growth factors for the avascular cornea. A disturbed tear film secretion results in an ocular dryness or Dry Eye Syndrome (DES), leading to an affected cornea. In the most drastic cases, the corneal homeostasis is defected, leading to vision impairment. While these observations are reflecting in importance of the tear film to maintain a healthy cornea, no study demonstrated the synergy between the LG and cornea homeostasis. Our latest results suggest a crucial implication of EDA signaling in the cornea-lacrimal gland feedback loop, both in physiological and pathophysiological conditions. The identification of secreted factors originating from the LG and signaling to the cornea is instrumental to the design of supplemented artificial tear drops that would enhance the cornea healing process. The cornea homeostasis defects, common in an aging population, combined to the incidence of corneal insults, support the urgency of developing a biomimetic tear film.