Artificial tears are the mainstay of dry eye therapy. However, there is a lack of quality research informing whether different artificial tears have advantages over others or placebo drops for the relief of signs and symptoms of dry eye.

Eligible participants were randomly allocated to the HP-Guar nanoemulsion or saline eye drops in this study for use 4 times a day for 4 weeks. Following a minimum washout period of 4 weeks, participants were crossed over to the alternate eye drop for 4 weeks of use. Subjective comfort and tear film parameters were measured 1 hour and 2 hours post eye drop instillation at the first visit, and again after 4 weeks of daily use.

With HP-Guar nanoemulsion eye drops, participants reported less symptoms of dryness and grittiness/burning/stinging, and greater overall satisfaction, whereas saline improved symptoms of dryness only. Both HP-Guar nanoemulsion and saline transiently increased tear lipid layer thickness, but no changes in tear film stability, tear osmolarity or tear film inflammatory markers were observed.

HP-Guar nanoemulsion eye drops were more effective for improving a range of dry eye symptoms in both the short and long term compared to saline.