67095
document
Contact lens lipid spoliation of hydrogel and silicone hydrogel lenses . PURPOSE The purpose of the study was to measure contact lens lipid spoliation of silicone hydrogel PureVision ( balafilcon A ) and hydrogel Acuvue 2 ( etafilcon A ) contact lenses worn for 10 hours single use ( DD ) and 7 days of extended wear ( EW ) . METHODS Two similar study populations ( DD , n = 55 ; EW , n = 53 ) , were enrolled at four study sites . In each population , a bilateral , randomized , crossover ( lens material ) , subject-masked experimental design was followed . Worn contact lenses were analyzed for lipid uptake using high-performance liquid chromatography by two laboratories : Alcon Laboratories ( right lens total uptake ) and OTG Research & Consultancy ( left lens total uptake and individual lipid classes ) . RESULTS Lipid uptake was different for the two materials : total lipid ( p < 0.007 ) , cholesterol esters ( p < 0.001 ) , cholesterol ( p < 0.001 EW only ) , and triglycerides/phospholipids ( p < 0.001 ) were higher for balafilcon A , whereas fatty acid ( p < 0.0025 EW only ) was higher for etafilcon A . The ratio of the extracted lipids was also different : higher percentages of triglycerides/phospholipids ( p < 0.001 ) and cholesterol ( p < 0.001 EW only ) for balafilcon A and higher percentages of fatty acids/di- and monoglycerides ( p < 0.014 ) for etafilcon A . CONCLUSIONS Total lipid uptake was highly material dependent . Both laboratories measured a greater uptake of lipids by the silicone hydrogel than the hydrogel material , a difference that was evident after only 10 hours of DD . Total lipid uptake was greater after 7 days of EW compared with 10 hours of DD . Of interest for contact lens spoliation and its avoidance was the differential lipid uptake profile , indicating material selectivity . Whereas greater differentiation between materials was possible after 7 days of EW for each material , the lipid uptake profile was similar for DD and EW , indicating a greater material effect than a wear modality effect .
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Intervention_Physical
contact lens lipid spoliation of silicone hydrogel PureVision ( balafilcon A )
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Intervention_Physical
hydrogel Acuvue 2 ( etafilcon A ) contact lenses
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Outcome_Physical
Lipid uptake
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Outcome_Physical
total lipid
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Outcome_Physical
cholesterol esters
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Outcome_Physical
cholesterol
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Outcome_Physical
triglycerides/phospholipids
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Outcome_Physical
fatty acid
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Outcome_Physical
ratio of the extracted lipids
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Outcome_Physical
triglycerides/phospholipids
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Outcome_Physical
cholesterol
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Outcome_Physical
fatty acids/di- and monoglycerides
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Outcome_Physical
Total lipid uptake
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Outcome_Physical
uptake of lipids
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Outcome_Physical
Total lipid uptake
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Participant_Condition
contact lenses
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Participant_Condition
extended wear ( EW )
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Participant_Sample-size
55
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Participant_Sample-size
53