TITLE:
Reinforcement of Eyelids in an Ex-Vivo Animal Model: Photocrosslinking of Tarsal Collagen by Exposure to Blue Light and a Ruthenium-Based Photosensitizer
AUTHORS:
Traian V. Chirila, Shuko Suzuki, Marwa Marchane
KEYWORDS:
Eyelid Laxity, Tarsal Collagen, Photochemical Crosslinking, Blue Light, Photosensitization, Ruthenium Complex, Mechanical Properties
JOURNAL NAME:
Open Journal of Ophthalmology,
Vol.16 No.4,
November
11,
2026
ABSTRACT: Photochemical crosslinking of the eyelid tarsal plate has been developed in our laboratories as a potential non-surgical treatment for palpebral laxity. Controlled exposure to ultraviolet A radiation (365 nm) in the presence of riboflavin as a photosensitizer was the protocol of choice for enabling mechanical reinforcement of the eyelid in order to offset the effects of laxity. In this study, tarso-conjunctival specimens excised from goat eyelids were exposed to blue light radiation (wavelength 470 nm, photon energy 2.64 eV) at different radiant exposures (0.9, 1.8, 3.6, and 6 J/cm2). Tris(2,2’-bipyridyl)ruthenium(II) dichloride hexahydrate was used as a photosensitizer in combination with sodium persulfate. The method provided statistically significant increases in stiffness and strength in the exposed eyelids and can circumvent the need for using ultraviolet A radiation. At the highest radiant exposure (6 J/cm2), the increase became insignificant, confirming our previous findings involving the ultraviolet A/riboflavin protocol. In conclusion, the protocol investigated in this study can be employed as an alternative procedure for reinforcing lax eyelids.