This randomized and controlled study aimed to examine the effects of hyaluronic acid on dry eyes. A total of 54 patients have been enrolled. All participants received topical hyaluronic acid. 30 patients received also oral hyaluronic acid (240 mg/day) for 3 months.
Results showed that topical hyaluronic acid can improve several markers of dry eyes. However, oral hyaluronic acid provided stronger effects. Even if the Ocular Surface Disease Index (OSDI) has been improved in both groups after one month, the Tear Break Up Time (TBUT) and the Corneal Fluorescein Staining (CFS) have been improved only in the oral hyaluronic acid group.
After 3 months, in comparison to 1 month, improvements in the OSDI and TBUT have been noted only in subjects receiving oral hyaluronic acid. Finally, at 3 months, significant differences were measured between the two groups for OSDI and CFS (p = 0.046 and p < 0.001 respectively).
Therefore, these results suggest that topical plus oral hyaluronic acid can reduce symptoms of dry eyes.
Kim Y, Moon CH, Kim BY, Jang SY. Oral Hyaluronic Acid Supplementation for the Treatment of Dry Eye Disease: A Pilot Study. J Ophthalmol. 2019 Sep 25;2019:5491626.