PURPOSE: Transient receptor potential vanilloid 1 (TRPV1) is an ionotropic receptor expressed in corneal epithelial cells and polymodal sensory neurons. Activation of polymodal nociceptors contributes to both physiological and pathological processes of the ocular surface, including pain sensation and wound healing. BL1332, a novel topical TRPV1 antagonist under development by Bausch + Lomb, is being evaluated as a potential therapeutic for ocular surface pain. In this study, we assessed the effect of 0.3% BL1332 on wound healing rate following central corneal keratectomy and evaluated its impact on corneal sensitivity in the intact contralateral eye.

METHODS: New Zealand White rabbits underwent partial keratectomy (8mm diameter, 100µm depth) on the left eye (OS). BL1332 0.3% was administered to both eyes four times daily (QID) for 9 days. Wound size was assessed once daily by fluorescein staining. Central corneal thickness was measured using optical coherence tomography (OCT). Corneal sensitivity in the intact contralateral eye (OD) was evaluated with a Cochet–Bonnet esthesiometer 10 minutes after the fourth daily dose.

RESULTS: Eyes treated with 0.3% BL1332 healed at a rate comparable to those treated with buffered saline solution (BSS) and faster (p<0.01 at day 6 post-keratectomy than eyes treated with 0.1 dexamethasone a corticosteroid known to delay wound healing but often prescribed post-surgery. after 9 days of 0.3 bl1332 qid administration os corneal thickness returned to baseline pre-surgery levels. lastly 0.3 bl1332 did not alter mechanical corneal sensitivity in the intact contralateral eye when compared with the anesthetic proparacaine p><0.01).>

CONCLUSIONS: Our results show that topical BL1332 administered QID did not impact wound healing rate and did not affect central corneal thickness after healing. In addition, BL1332 did not reduce corneal sensitivity, supporting an analgesic, rather than anesthetic, mechanism of action.