Kinetic Deposition of Polar and Non-polar Lipids on Silicone Hydrogel Contact Lenses

ABSTRACT

Purpose: This study investigated kinetic lipid uptake to four silicone hydrogel (SiHy) lenses over a period of four weeks, using an in-vitro radiolabel method.

Methods: Four contemporary monthly replacement SiHy lenses (lotrafilcon B, senofilcon C, comfilcon A, samfilcon A) were incubated in three different solutions: 1) An artificial tear solution (ATS) containing ¹⁴C-labeled phosphatidylcholine (PC), 2) an ATS containing ¹⁴C-cholesteryl oleate (CO) and 3) an ATS containing four ¹⁴C-radiolabeled lipids (PC, phosphatidylethanolamine, CO, and cholesterol (total lipid)). After 16 hours, lipids were extracted twice from the lenses with chloroform:methanol and the radioactive counts determined the lipid quantities to simulate 1 day of wear. OPTI-FREE PureMoist (Alcon) was used to clean and disinfect the remaining lenses daily and the lipid quantities were further determined after 2 weeks and 4 weeks.

Results: The amount of total lipid increased for all lenses over time (p < .01). After four weeks, total lipid accumulated was 20.26 ± 0.15 µg/lens for senofilcon C, which was significantly higher (p < .01) than all other lens materials (samfilcon A – 17.84 ± 0.21; comfilcon A – 16.65 ± 0.12; lotrafilcon B – 7.41 ± 0.56 µg/lens). CO was highest on lotrafilcon B (1.26 ± 0.13 µg/lens) and senofilcon C attracted the most PC (3.95 ± 0.12 µg/lens) compared to the other materials.

Conclusion: The amount of both polar and non-polar lipid deposition on monthly replacement SiHy lenses increased over 4 weeks, with significant differences being seen between lens materials.

KEYWORDS:

• Lipid deposition
• silicone hydrogel contact lenses
• cholesteryl oleate
• phosphatidylcholine
• artificial tear solution

Declaration of interest

Over the past 3 years, L. Jones or his research group at CORE has received research funding and/or honoraria from one or more of the following companies: Advanced Vision Research, Alcon, Allergan, Contamac, CooperVision, Essilor, GL Chemtech, Inflamax Research, Johnson & Johnson Vision Care, Inc., SightGlass, Menicon, Nature’s Way, Novartis, Ocular Dynamics, Oculus, Safilens, Ophtecs, Santen, Shire, TearLab, TearScience. Supported by Alcon Research, Ltd.

L. Subbaraman was employed at CORE while the study was conducted and is currently at Alcon Laboratories, Inc.

C. Scales and Z. Fadli are currently employed by Johnson & Johnson Vision Care, Inc.

Additional information

Funding

Funding for this study was provided by Johnson & Johnson Vision Care, Inc.