Efficacy and safety of 0.18% sodium hyaluronate in patients with moderate dry eye syndrome and superficial keratitis

Background: Sodium hyaluronate (SH) is used in patients with dry eye. We evaluated the efficacy and safety of SH and carboxymethylcellulose (CMC) in the treatment of dry eye syndrome with superficial keratitis. Methods: A total of 22 patients with moderate dry eye and superficial keratitis were enrolled in a prospective, randomised, masked-observer, parallel-group, single-centre study. Patients were randomly assigned to a 0.18% SH or 1% CMC solution for a 2-month period. In addition to the commonly assessed parameters in patients with dry eye ( among others symptoms and corneal staining with fluorescein), flow cytometry analysis of CD44, HLA DR expressions in impression cytology was investigated as a potential efficacy parameter. Results: Both treatments improved the symptoms and ocular surface and were well tolerated. SH significantly ( p< 0.05) decreased CD44 values compared with CMC. Comfort was significantly ( P< 0.05) better in the SH group than that in the CMC group throughout the study. Recovery in keratitis ( type, extent and depth) and symptoms were faster in the SH group than in the CMC group. Blurred vision was reported by patients in the CMC group only. Conclusions: SH was well tolerated and tended to show a faster efficacy than did the CMC-based formulation in patients with moderate dry eye and superficial keratitis. SH could therefore advantageously be prescribed from the early stages of dry eye disease. This study also showed that flow cytometry in impression cytology specimens is a reliable tool for exploring the ocular surface at the epithelial level and that CD44, in addition to HLA DR, could be an interesting endpoint for future trials in dry eye syndrome with products based on SH.