Effects of lubricating agents with different osmolalities on tear osmolarity and other tear function tests in patients with dry eye

Abstract

Purpose: To evaluate the effects of different artificial tear eye drops on Ocular Surface Disease Index (OSDI), tear osmolarity, Schirmer's I test, and tear break-up time (TBUT) in patients with dry eye disease.

Materials and methods: This 12-week, single-institution, single-masked, randomized, pilot study was conducted in Turkey between March and July 2012 in patients with dry eye. Patients were randomly assigned to receive Systane® for their right eye and Eyestil® for their left eye or to receive Tears Naturale II® for their right eye and Refresh Tears® for their left eyes. Outcomes were assessed at baseline and weeks 2, 4 and 12 after treatment initiation.

Results: Twenty-two patients received Systane (right eye) and Eyestil (left eye) and 21 patients received Tears Naturale (right eye) and Refresh (left eye). At each visit and for each outcome, each treatment group demonstrated a significant improvement from baseline (p < 0.001); however, none of these outcomes were significantly different among treatment groups at any visit. At week 12, the mean OSDI improvement was similar between the Systane/Eyestil group (-26.4 ± 10.6) and the Tears Naturale/Refresh group (-27.6 ± 14.8). The mean tear osmolarity decrease (mOsm/L) at week 12 was -33.8 ± 8.3 for Eyestil, -30.3 ± 9.2 for Refresh, -28.4 ± 8.2 for Systane and -25.7 ± 13.1 for Tears Naturale. The mean Schirmer's test increase at week 12 (mm/5 min) was 6.7 ± 3.4 for Eyestil, 6.4 ± 2.9 for Systane, 4.7 ± 2.4 for Tears Naturale and 4.7 ± 2.8 for Refresh. The mean TBUT increase at week 12 (s) was 7.0 ± 3.4 for Systane, 6.1 ± 3.3 for Eyestil, 5.8 ± 2.3 for Tears Naturale, and 5.6 ± 2.8 for Refresh.

Conclusion: All four artificial tear formulations were effective in relieving dry eye signs and symptoms. Although the greatest improvement in two of the objective tests was achieved by Eyestil, the drug with the lowest osmolality, differences among the four artificial tear eye drops were not statistically significant.