Comparing the Efficacy and Tolerability of Two 0.3% Hyaluronic Acid Eye Drop Preparations for Dry Eye Disease: a Randomized Trial

Purpose: To evaluate the efficacy and tolerability of a new 0.3% non-preservative low viscosity hyaluronic acid (HA) preparation (Kynex 3), compared to the same concentration of HA (Hyalein Mini 0.3%) for the treatment of dry eye disease. Methods: A prospective, single-center, randomized, double-blinded trial (group 1; Kynex 3 vs group 2; Hyalein Mini 0.3%) was performed over 8 weeks. Patients with dry eye symptoms and ocular surface staining score ≥ 2 by the Oxford system, and tear break-up time (TBUT) < 10 s were included. Efficacy outcomes included improvements in TBUT, Schirmer I value, corneal and conjunctival staining scores, and ocular surface disease index (OSDI) at 4 and 8 weeks. Tolerability was assessed using instillation discomfort scores on day 0 and at 4 and 8 weeks. Results: Twenty-three patients were analyzed. Both 0.3% HA preparations significantly improved the TBUT and OSDI scores at 4 and 8 weeks compared with those on day 0. Reduction in the corneal staining score and instillation discomfort scores were significant in group 1 at week 4, and both groups showed a similar statistically significant reduction at week 8. Conjunctival staining and Schirmer I scores did not improve in either group. Conclusions: Both 0.3% HA eye drops effectively improved dry eye symptoms and TBUT. Regarding corneal staining and instillation discomfort scores, significant within-group reduction was shown in one group (Kynex 3) at week 4, without a significant between-group difference.