Could a molecule developed for skin rejuvenation be repurposed to fight dry eye? A team of Italian researchers thinks so.

As the dry eye cascade begins to ramp up, one consequence is a decline in lactoferrin production. This tear protein plays a vital role in preventing infection and fighting inflammation; its absence compromises the ocular surface. Lactoferrin levels also decrease with age, particularly in post-menopausal women, increasing the propensity for dry eye in this population. 

A new study in Cornea investigated the use of lactobionic acid (LA)—available in numerous dermatologic products to reduce wrinkles—as an analog for lactoferrin. LA has properties similar to the lactoferrin in natural tears, the authors note. It is highly hygroscopic (capable of absorbing moisture), a powerful antioxidant and an iron chelator. Additionally, LA inhibits matrix metalloprotease activity, favors wound healing and inhibits bacterial growth.

Using rabbit corneas, the team studied wound healing after administration of LA alone or in combination with hyaluronic acid. The study found LA—with or without hyaluronic acid—favored wound healing both in vitro and in vivo. Researchers reported the wound-healing assays of 4% lactobionic acid with 0.15% hyaluronic acid showed a blunted increase of matrix metallopeptidase-9 and TGF-β in tears and corneal tissue. 

The study also noted the presence of 4% lactobionic acid resulted in slower growth of cultured bacterial isolates. 

If further research supports LA use in dry eye, the molecule could be delivered to the eye in an artificial tear product, the researchers note. 

Olivieri M, Cristaldi M, Pezzino S, et al. Experimental evidence of the healing properties of lactobionic acid for ocular surface disease. Cornea. 2018 Aug;37(8):1058-63.