Dry eyes are caused by a lack of tear production or fast evaporation. One method for managing the systems is to use “artificial tear” products—eye drops that can lubricate eyes. Hyaluronic acid (HA) has been investigated as a component of artificial tear products due to its ability to bind to ocular surface cells, enhance wound healing, and reduce the viscosity of the overall fluid.[1]
A 2021 meta-analysis of randomized, controlled trials on participants with dry eye syndrome compared eye drops containing HA with eye drops not containing HA, including many artificial tear products with other ingredients.[2] Hyaluronic acid improved tear production relative to saline and some artificial tear products, but not all artificial tear products. The same was true of tear break-up time and Ocular Surface Disease Index, while an analysis comparing HA products to those without HA didn’t find a difference for Corneal Fluorescein Staining Score. Trials where HA is compared to artificial tear products are often confounded with other ingredients that make it difficult to discern the efficacy of HA. A 0.3% HA solution appeared to be the most effective relative to saline, though the evidence doesn't allow us to say that this dose is the best with much certainty. Doses as low as 0.1% have seen some benefit and may be useful as an addition to multi-ingredient artificial tear products, though much more research with the proper study design is needed to evaluate the ideal formulae.