Combining Sodium Hyaluronate and Polyvinylpyrrolidone Therapies for the Rabbit Cornea: A New Approach to Relief of the Human Dry Eye Syndrome

Purpose of the study: The novel combination of 0.1% sodium hyaluronate (HA) and 5.0% polyvinylpyrrolidone (PVP) into one eyedrop was investigated to test the hypothesis of its increased relief of dry eye syndrome (DES). Materials and methods: We evaluated HA and PVP, either alone, or in combination, by utilizing 16 rabbits, where their right eyes received one or two different eyedrops, and their left eyes, as controls, received none. The DES replica in rabbits was induced by 0.1% benzalkonium chloride (BAC) eyedrops. BAC was instilled into the right eyes of all rabbits, which were divided into four groups of four. In Group 1M, the rabbits received only BAC. A second eyedrop given to the right eyes of Group 2M was HA, of Group 3M was PVP, and of Group 4M was the combination of both HA and PVP. All eyes were followed clinically for 14 d, and thereafter, examined histopathologically. Results: Clinically, the HA+PVP combination yielded the least perilimbal conjunctival erythema (p<0.05), and the least corneal epithelial fluorescein staining (p<0.001) compared to each treatment alone. Histopathologically, all four rabbits' right eyes in the combination group 4M displayed the greatest preservation of the corneal epithelium (p<0.001) and of the perilimbal conjunctival goblet cell density (p<0.001). Conclusions: This unique combination of both HA and PVP into one eyedrop, was more potent than either treatment alone in protecting the ocular surface. A preparation, containing both HA and PVP may become useful for DES patients.