Cationic oil‐in‐water emulsions protect and restore function of the injured ocular surface

Abstract Purpose Ocular surface damage is a consequence of tear instability arising from numerous inciting events: preserved eye drops, contact lens wear, systemic medications, environment and age. While unpreserved eye drop reduce iatrogenic toxicity they do not restore the deficient tear film which leads to ocular surface injury. Cationic oil‐in‐water emulsions have been shown to restore and reduce evaporation of the tear film. We studied the effect of cationic emulsions (Cationorm® and Catioprost®) in established animal models of ocular surface injury. Methods Acute toxicity and local tolerance were evaluated in rabbits. Healing properties were assessed in a rat model of corneal scraping. Abrasions were treated for 5 days, and corneas were evaluated clinically and histologically. Conjunctival function was assessed by goblet cell (GC) count and MUC5 immunostaining. The kinetics of ocular surface healing was assessed in an in vitro scraping assay. Results Neither Cationorm® nor Catioprost® induced toxicity as evidenced by clinical and confocal microscopy scoring. Catioprost® was well tolerated, with a reduced (‐42%) occurrence of hyperemia when compared to Xalatan®. In rats, Catioprost® improved healing, protected GC and maintained normal MUC5 secretion. In vitro, the cationic emulsions improved cell migration and maintained MUC4 expression. Conclusion Cationic emulsions were well tolerated. In contrast to preserved and unpreserved ophthalmic drops, cationic emulsions promoted healing, restored function of injured ocular surface, and protected against ocular surface injury. The findings suggest that cationic emulsions by augmenting the tear film may benefit patients with ocular surface disease. Commercial interest