Deposition of Triglyceride on Soft Contact Lenses from Lipid-Containing Artificial Tears

Abstract

Objective: To determine the amount of triglyceride deposition from a lipid-containing artificial tear eye drop (Endura^®) on three different types of contact lenses after one day and one month of simulated use.

Methods: Simulated use of artificial tears was performed in vitro on three different types of contact lenses, including: high water content (HW), low water content (LW), and silicone hydrogel (SI) contact lenses. To simulate one day of use, contact lenses were incubated in artificial tear solution for 16 hours. To simulate a one month of use, they underwent repeated cycles of 16-hour incubation in artificial tear solution, lens cleaning, and 8-hour storage in a multipurpose solution daily for 30 days. Triglyceride deposited was extracted and determined.

Results: After one day of simulated use, amount of deposited triglyceride was significantly different among 3 types of contact lenses with the highest deposition in SI followed by LW and HW contact lenses; the corresponding values (mean ± SD) were 3.79 ± 0.35, 0.84 ± 0.27, and 0.26 ± 0.17 µg/lens, respectively. Only between SI and HW was it found to be statistically different. After one month of simulated use, deposition on SI lenses was slightly increased (6.56 ± 1.10 µg/lens) with that on LW and HW lenses remaining low (0.10 ± 0.12 and 0.55 ± 0.34 µg/lens, respectively).

Conclusion: Triglyceride from lipid-containing artificial tears can absorb into contact lenses, particularly those made of silicone hydrogel, most notably after long periods of use. However, levels of triglyceride deposition are relatively low, when compared to lipid deposition from normal tear films during regular use.