Sodium hyaluronate eyedrops in the treatment of dry eyes.
BACKGROUND--Several studies in the past have attempted to demonstrate the efficacy of sodium hyaluronate in the treatment of dry eyes. However, results have been conflicting and a definite conclusion has not yet been reached. This study recruited a larger group of patients and has incorporated for the first time both fluorescein and rose bengal staining in the evaluation of the epithelium. METHODS--Eighteen albino rabbit corneas were used in a basic animal study to demonstrate the efficacy of sodium hyaluronate by comparing the effects on the rate of epithelial healing. The optimal concentration to be used in the clinical trial was determined from the results of the basic study. In the clinical study 104 patients with dry eye syndrome were enrolled in a double masked controlled clinical trial. Patients received sodium hyaluronate drops in one eye and control medication in the other eye for 4 weeks. Grading of subjective symptoms and clinical examinations were performed at 2 and 4 weeks. RESULTS--In the animal study sodium hyaluronate at concentrations of 0.1% and 0.5% significantly accelerated the recovery time of iodine vapour induced corneal erosions (p < 0.01). In the clinical study no statistical significance was observed in the improvement of subjective symptoms or rose bengal staining, while fluorescein scores significantly improved in eyes receiving sodium hyaluronate (p = 0.0001) at 4 weeks. CONCLUSION--Sodium hyaluronate drops applied in six daily doses could not be demonstrated to offer advantages over conventional tear supplies in the improvement of subjective symptoms, but may play a role in maintaining a healthy corneal epithelium.