Sodium hyaluronate eye drops of different osmolarity for the treatment of dry eye in Sjogren's syndrome patients

Aim: To study the effect of the treatment of dry eye in Sjogren's syndrome patients with hypotonic or isotonic hyaluronate eye drops. Methods: 40 Sjogren's syndrome patients were divided in two groups and treated as follows: group I with hypotonic (150 mOsm/l) 0.4% hyaluronate eye drops; group 2 with isotonic 0.4% hyaluronate eye drops. The eye drops were instilled six times a day for 90 days. Grading of subjective symptoms, break up time (BUT), corneal fluorescein staining, conjunctival rose bengal staining, Schirmer's I test, and conjunctival impression cytology were carried out at 0 and 15, 30, 90 days from the beginning of the study. Patients were examined in a blind fashion, For the statistical analysis the Student's t test, Mann-Whitney U test, and chi(2) test were performed. Results: Symptoms were statistically significantly improved at day 15 in both groups but group I patients had a global score statistically significantly better group 2 (p = 0.02). At day 15 group I patients had an improvement from baseline values of BUT (p = 0.003), fluorescein, and rose bengal score (p = 0.000001 and p = 0.0004 respectively). Group 2 patients had, at day 15, an improvement of BUT and fluorescein score compared to baseline values (p = 0.05 and p = 0.0001 respectively). A comparison between the two groups showed better results for group 1 patients at day 15 for rose bengal stain (p = 0.01) and for BUT (p = 0.05) and fluorescein score (p = 0.0003) at day 90. The conjunctival impression cytology showed that group I had a statistically significant better total score than group 2 starting from day 15 and lasting throughout the study (p < 0.02). Also group 2 patients showed an improvement from baseline values starting from day 30 (p = 0.000005). Conclusion: Hyaluronate eye drops are useful for treating severe dry eye in Sjogren's syndrome patients. The use of a formulation with pronounced hypotonicity showed better effects on corneoconjunctival epithelium than the isotonic solution.