In vivo dehydration of silicone hydrogel contact lenses
Morgan, Philip B. & Efron, Nathan (2003) In vivo dehydration of silicone hydrogel contact lenses. Eye and Contact Lens, 29(3), pp. 173-176.
PURPOSE: To benchmark the performance of new-generation silicone hydrogel contact lenses in terms of their in vivo hydration characteristics and to highlight the possible clinical ramifications of any changes observed. METHODS: Thirteen subjects (four men and nine women with a mean age of 24.8 +/- 5.0 years) wore a silicone hydrogel lens (PureVision, Bausch & Lomb, Rochester, NY) in one eye and a conventional hydrogel lens (ACUVUE 2, Johnson & Johnson Vision Care, Jacksonville, FL) in the other eye for 4 weeks on an extended-wear basis. A gravimetric method was used to determine lens water content and dehydration during the intended lifespan of the lenses. RESULTS: For the PureVision lens, the water content was 38.3% +/- 0.9%, 35.2% +/- 1.1%, and 35.3% +/- 1.7% at baseline and after 2 and 4 weeks of wear, respectively (F=28.4, P<0.0001). For the ACUVUE 2 lens, the water content was 58.1% +/- 0.6% and 52.1% +/- 1.3% at baseline and after 2 weeks of wear, respectively. Thus, after 2 weeks of wear, absolute dehydration was 2.8% +/- 1.8% and 6.0% +/- 1.3% for the PureVision and ACUVUE 2 lenses, respectively (t=6.8, P<0.0001). The mass of deposition was calculated to be 568 +/- 457 microg for the PureVision lens and 1,660 +/- 499 microg for the ACUVUE 2 lens (t=5.1, P=0.0003). CONCLUSIONS: The ACUVUE 2 lens underwent a greater degree of lens dehydration, causing a reduction in oxygen permeability (3.6 barrer), and deposition after 2 weeks of extended wear. The loss of water from the PureVision lens was paradoxically associated with a 6.0-barrer increase in oxygen permeability after 4 weeks of extended wear.
Impact and interest:
Citation counts are sourced monthly from and citation databases.
These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.
Citations counts from theindexing service can be viewed at the linked Google Scholar™ search.
|Item Type:||Journal Article|
|Additional Information:||Self-archiving of the author-version is not yet supported by this publisher.
For more information, please refer to the journal’s website (see hypertext link) or contact the author.
|Keywords:||Dehydration, Deposition, Hydrogel contact lens, Silicone hydrogel contact lens, Water content|
|Subjects:||Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > OPTOMETRY AND OPHTHALMOLOGY (111300)|
|Divisions:||Current > Research Centres > Centre for Health Research
Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
|Copyright Owner:||Copyright 2003 Lippincott Williams & Wilkins|
|Deposited On:||28 Nov 2007 00:00|
|Last Modified:||29 Feb 2012 13:29|
Repository Staff Only: item control page