In vitro lipid deposition on hydrogel and silicone hydrogel contact lenses.
OBJECTIVE
To understand various soft contact lens materials' ability to adsorb common tear lipids.


METHODS
Ten unworn polymers of nine types were individually soaked in 1.0 mL of 1.75 μg/mL cholesterol oleate or 1.0 mL of 0.5 μg/mL phosphatidylcholine solutions for 1 or 14 days. The adsorbed lipids were extracted with chloroform-methanol, which underwent assay quantification for cholesterol oleate and inorganic phosphate.


RESULTS
More phosphatidylcholine was extracted after 14 days than after 1 day in only lotrafilcon B, balafilcon A, and enfilcon A (all P < 0.005). After 1 day of incubation in phosphatidylcholine, 0.54 to 4.17 μg/lens phosphatidylcholine was recovered from the polymers, and after 14 days of incubation in phosphatidylcholine, 0.58 to 5.77 μg/lens phosphatidylcholine was recovered from the polymers. Etafilcon A had significantly more cholesterol oleate at 1 day than at 14 days, and lotrafilcon A, lotrafilcon B, and balafilcon A had significantly more cholesterol oleate at 14 days than at 1 day (P < 0.005). After 1 day of incubation in cholesterol oleate, 0.14 to 4.80 μg/lens cholesterol oleate was recovered from the polymers. After 14 days of incubation in cholesterol oleate, 1.40 to 6.84 μg/lens cholesterol oleate was recovered from the polymers.


CONCLUSIONS
Hydrogel and most silicone hydrogels appear to adsorb lipids relatively quickly (i.e., within the first day). Although there is some variability in the amounts recovered across materials, it is uncertain whether these differences have any clinical significance.
Pucker
Andrew D
AD
Ohio State University, College of Optometry, Columbus, Ohio 43218-2342, USA.
Thangavelu
Mirunalni
M
Nichols
Jason J
JJ
D000042:Absorption; D002788:Cholesterol Esters / Q000378:metabolism*; D003263:Contact Lenses, Hydrophilic; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D020100:Hydrogels; D050356:Lipid Metabolism; D010713:Phosphatidylcholines / Q000378:metabolism*; D012828:Silicones
D002788:Cholesterol Esters; D020100:Hydrogels; D010713:Phosphatidylcholines; D012828:Silicones; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C014409:cholesteryl oleate