Comparison of Three Lubricant Eye Drop Solutions in Dry Eye Patients

Purpose. Lubricant eye drops that restore physiological osmolarity represent a promising strategy for dry eye syndrome as hyperosmolarity plays a central role in this disease. This preliminary study compared three lubricant eye drop solutions with different osmolarities and compositions in subjects with this condition. Methods. Subjects with dry eye syndrome undergoing treatment with benzalkonium chloride-containing lubricant eye drops were randomized to Carnidrop (n = 9), Optive (n = 9), or Blu Sal (n = 9). Fluorescein break-up time (FBUT) and Ocular Protection Index (OPI) were measured at baseline, 15 min, and 60 min after instillation to evaluate the stability and quality of the tear film. Results. At 15 min, a significant increase in FBUT vs. baseline was reported with Carnidrop (from 2.0 +/- 0.8 to 4.8 +/- 2.0; p = 0.004) but not in patients who received Optive or Blu Sal. At 60 min, FBUT was significantly increased vs. baseline with Carnidrop (from 2.0 +/- 0.8 to 6.0 +/- 2.8, p = 0.001) and Optive (from 2.9 +/- 2.8 to 4.3 +/- 2.9, p = 0.004) but not with Blu Sal. At 15 min, OPI was significantly increased from baseline in only the Carnidrop group (from 0.4 +/- 0.2 to 1.0 +/- 0.4, p = 0.003). This increase was significantly greater with Carnidrop than with Blu Sal (p = 0.003). At the 60 min evaluation, OPI remained significantly increased from baseline in only the Carnidrop group (p = 0.003). Conclusions. Carnidrop produces a larger increase in FBUT and OPI than Optive and Blu Sal in subjects with dry eye syndrome over a 1 h period, possibly because of its hypo-osmolarity and high osmolyte (in particular l-carnitine) content. The instillation of compounds that improve the quality and stability of the tear film, which are impaired in dry eye syndrome, could be effective in the treatment of this condition