Photochemical Crosslinking of Tarsal Collagen as a Treatment for Eyelid Laxity: Evaluation in Ex Vivo Human Tissue

This study demonstrated that UV-A irradiation (365 nm, 75 mW/cm² for 3 minutes) in the presence of a riboflavin derivative significantly increases the tensile stiffness and strength of excised human tarsal plates, establishing a potential nonsurgical treatment for eyelid laxity. Thirteen cadaveric tarsal specimens were exposed to UV-A light, achieving a radiation fluence of 13.5 J/cm², while paired controls remained unirradiated. BioTester 5000 data revealed a statistically significant post-irradiation increase in stress (≈77–475%) and Young’s modulus, confirming crosslinking-induced stiffening without histologic damage to the Meibomian glands or collagen organization. Histopathologic evaluation using hematoxylin–eosin, Masson trichrome, and Van Gieson staining confirmed intact collagen morphology and preserved glandular architecture, validating the method’s safety and efficacy.