Assessment of ultraviolet B-blocking effects of weekly disposable contact lenses on corneal surface in a mouse model

Purpose: Weekly disposable soft contact lenses have been widely used recently, but their shield effects against ultraviolet (UV) irradiation remain to be evaluated. This study investigated the bioprotective effects of several weekly soft contact lenses against UVB irradiation on the corneal surface in a mouse model. Methods: Fifty ICR mice were randomly divided into fve groups: (1) blank control, (2) exposed to UVB without contact lens protection, (3) exposed to UVB and protected with Viflcon A contact lenses, (4) exposed to UVB and protected with Etaflcon A contact lenses, and (5) exposed to UVB and protected with HEMA+MA contact lenses. The exposure to UVB irradiation was performed at 0.72 J/cm2/day after anesthesia for a 7-day period, followed by cornea surface assessment for smoothness, opacity, and grading of lissamine green staining. Tissue sections were prepared for hematoxylin and eosin staining and immunohistochemical detection by using antibodies against myeloperoxidase, cytokeratin-5, P63, Ki-67, nuclear factor-kappa B (p65), cyclooxygenase-2, Fas L, and Fas. Results: The results showed impaired corneal surface with myeloperoxidase+ polymorphonuclear leukocyte infltration into the stroma after UVB exposure, in contrast to the intact status of the blank controls. The corneas with Etaflcon A and HEMA+MA contact lenses maintained more cells positive for cytokeratin-5, P63, and Ki-67 compared to those with Viflcon A or without contact lens protection. Furthermore, less proinfammatory factors, including nuclear factor-kappa (p65), cyclooxygenase-2, Fas L, and Fas, were induced in the corneas protected by Etaflcon A and HEMA+MA. Conclusions: This study demonstrated various protective effects of weekly disposable contact lenses against UVB irradiation. The mouse model used in the present study may be used extensively for in vivo assessment of UV shield efficacy.