Low concentration of sodium hyaluronate temporarily elevates the tear film lipid layer thickness in dry eye patients with lipid deficiency.

Aim: To investigate the effects of different concentrations of artificial tears on lipid layer thickness (LLT) and blink rate (BR) in dry eye patients.
Methods: This study included 106 eyes of 58 patients with dry eye. The lipid deficiency type was defined as the LLT baseline <75 nm. The LLT and BR were measured at baseline and 1, 5 and 15min after the instillation of 0.1% or 0.3% sodium hyaluronate (SH) eye drops by using the LipiView ocular surface interferometer.
Results: In the lipid deficiency group, the LLT increased from baseline at 1min post instillation. The LLT after the instillation of 0.1% SH was significantly higher than that after the instillation of 0.3% SH ( P <0.001). The LLT returned to baseline at 15min post instillation of 0.1% SH and at 5min post instillation of 0.3% SH. In the non-lipid deficiency group, the LLT decreased from baseline at 1min and returned to baseline at 5min for both treatments. The BRs were not significantly different at different time points for both treatments.
Conclusion: SH eye drops induce a short-term increase in LLT of patients with lipid deficiency. A low concentration of artificial tears have a stronger effect than a high concentration of artificial tears on the increase in LLT. In comparison, SH eye drops induce a transient and slight decrease in LLT of patients without lipid deficiency. A low concentration of artificial tears might be better for patients with lipid deficiency.