Prevention of UV-induced damage to the anterior segment using class I UV-absorbing hydrogel contact lenses.

Purpose: To determine whether class I ultraviolet (UV) light-blocking contact lenses prevent UV-induced pathologic changes in a rabbit model.
Methods: Twelve rabbits were assigned to 1 of 3 treatment groups (n = 4), as follows: senofilcon A (class I UV blocking) contact lenses; lotrafilcon A contact lenses (no reported UV blocking); no contact lens. The contralateral eye was patched without a contact lens. Animals received UV-B (1.667 J/cm(2)) exposure daily for 5 days. Postmortem tissue was examined as follows: in the cornea, the expression of matrix-metalloproteinases (MMPs) was evaluated by zymography, and apoptosis was evaluated by TUNEL and caspase-3 ELISA; ascorbate in the aqueous humor was evaluated by nuclear magnetic resonance spectroscopy; crystalline lens apoptosis was evaluated by TUNEL and caspase-3 ELISA.
Results: Exposed corneas showed a significant increase in MMP-2 and -9, TUNEL-positive cells, and caspase-3 activity in the lotrafilcon A group compared with the senofilcon A group (all P = 0.03). A significant decrease in aqueous humor ascorbate was observed in the exposed lotrafilcon A lens-wearing group compared with the exposed senofilcon A lens-wearing group (P = 0.03). Exposed crystalline lenses had significantly increased caspase-3 activity in the lotrafilcon A group compared with the senofilcon A group (P = 0.03). Increased numbers of TUNEL-positive cells were noted in both the lotrafilcon A and the non-contact lens groups.
Conclusions: The authors show that senofilcon A class I UV-blocking contact lenses are capable of protecting the cornea, aqueous humor, and crystalline lens of rabbits from UV-induced pathologic changes.