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/cm²) 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.

Objective—To evaluate effect of adjunctive treatment with tetracycline analogues on time to complete corneal reepithelialization in dogs with nonhealing (ie, refractory) corneal ulcers. Design—Randomized controlled clinical trial. Animals—89 dogs with refractory corneal ulcers. Procedures—Corneal ulcers were treated via debridement and grid keratotomy. Dogs were assigned to receive 1 of 3 treatment regimens for up to 6 weeks: doxycycline (5 mg/kg [2.27 mg/lb], PO, q 12 h) with topically applied ophthalmic ointment containing neomycin, polymyxin B, and bacitracin (ie, triple antibiotic ointment; q 8 h); cephalexin (22 mg/kg [10 mg/lb], PO, q 12 h) with topically applied oxytetracycline ophthalmic ointment (q 8 h); or a control treatment of cephalexin (22 mg/kg, PO, q 12 h) with topically applied triple antibiotic ointment (q 8 h). Healing was monitored via measurements of the wound with calipers and evaluation of photographs obtained every 2 weeks. Treatment effectiveness was evaluated by wound healing and decreased signs of pain. Results—The Boxer breed was overrepresented in all groups. At the 2-week time point, wound healing was significantly more common in small-breed dogs, compared with large-breed dogs. Dogs treated with oxytetracycline ophthalmic ointment had a significantly shorter healing time than did dogs receiving the control treatment. Corneal ulcers in dogs that received doxycycline PO healed more rapidly than did ulcers in dogs in the control treatment group; however, this difference was not significant. Conclusions and Clinical Relevance—Topical tetracycline ophthalmic ointment was a safe, inexpensive, and effective adjunctive treatment for refractory corneal ulcers in dogs.