Purpose:Tisochrysis lutea is a marine microalga known for its anticancer and antioxidant properties. This study aimed to investigate the efficacy and safety of T. lutea in adults with dry eye symptoms.

Methods:One hundred participants with dry eye symptoms were enrolled and divided into two groups: one received T. lutea powder (test group), and the other received control food (placebo, control group) for 12 weeks. Subsequently, the measurements of ocular surface disease index (OSDI), tear secretion (Schirmer’s test), tear break-up time (TBUT), corneoconjunctival staining, and safety assessments were compared between the test and control groups.

Results:In terms of the OSDI score, the value for the test group decreased by 6.51 points after 12 weeks of T. lutea powder intake, compared with baseline, whereas that in the control group decreased by 2.88 points, demonstrating a significant difference between the two groups (p = 0.002). The results of Schirmer's test also showed significant improvements: in the test group, the result for the right eye increased by 1.33 ± 3.71 after 12 weeks (p = 0.020), and that for the left eye increased by 1.93 ± 3.33 (p = 0.0003). However, no significant increases in the results were observed in the control group. Additionally, TBUT showed a significant increase from baseline in the right eye of the test group after 6 weeks of T. lutea powder intake (p = 0.043).

Conclusions:After 12 weeks of consumption in the powdered form, T. lutea improved the symptoms of dry eye and increased tear production. Therefore, T. lutea can be used as an eye supplement for adults with dry eye symptoms.