Higher concentrations of hyaluronic acid (0.30%) have proven to be more effective than 0.10% and 0.18% HA in dry eye experimental studies in mouse. In order to confirm whether the same assumptions apply in humans, Calonge and colleagues report for the first time the results of a multicentric, non-inferiority clinical trial comparing Vismed Gel (0.3% HA) to Vismed (0.18% HA) in patients with moderate to severe dry eye disease. Eighty-one patients were randomised and followed up for 12 weeks.
At Day 35, both groups had a significant improvement in corneal and conjunctival staining by fluorescein compared to baseline, with no significant difference between the two treatment groups. The sensitivity analysis on the intention-to-treat population confirmed this non-inferiority.
Global performance of 0.30% and 0.18% hyaluronic acid (HA) evaluated by investigators and patients with moderate to severe dry eye disease over 84 days of follow-up. The figures represent the percentage of subjects “satisfied” or “very satisfied” with either concentration.
At Day 35 and 84, the score of ocular symptoms significantly improved compared to baseline for both treatment groups. The tear break-up time (TBUT) was slightly but significantly improved at Day 84 for the Vismed group only. The increase was at the limit of significance for the Vismed Gel group. The difference between both groups was not statistically significant. Both products were well tolerated, with three mild to moderate adverse events in each group.
In conclusion, the Calonge study demonstrated the non-inferiority of Vismed Gel compared to Vismed over 12-week follow-up period, in patients with moderate to severe DED. Both concentrations induced significant and equivalent improvements in DED signs and symptoms, with reduced Oxford and van Bijsterveld scores and less ocular dryness symptoms. A non-significant numerical decrease in the frequency of instillation and faster conjunctival epithelial healing were noted with Vismed Gel, probably related to its gel structure and higher HA concentration providing prolonged comfort without causing visual disturbances. Based on these findings, the authors propose that the use of Vismed Gel might be of interest particularly at bedtime or during the day in more severe conditions.
Further investigations (possibly including sub-groups of patients) and a different study design are needed to better clarify the difference between the two concentrations of hyaluronic acid in our eye-drops.
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