Surface hydration of hydrogel contact lenses
A hand refractometer was used to measure the surface hydration of soft contact lenses of three different water contents, in a randomized, double masked study conducted on nine subjects. No statistically significant difference was found after 30 minutes of lens wear between the hydration levels at the front and back surfaces of Permathin (42.5% nominal water content) and Snoflex 50 (50% nominal water content) hydrogel lenses; however, there was a significant difference for Gelflex 60 (60^ nominal water content) lenses, the back surface being more hydrated than the front surface. These findings suggest that there may be a water gradient between the front and back surfaces of higher water content hydrogel lenses during wear. Whilst the magnitude of the difference between surface hydration levels is small and of little consequence in the routine clinical measurement of water content using a hand refractometer, this phenomenon could be of aetiological significance with respect to the occurrence of multiple corneal erosions observed in patients wearing very thin, high water content lenses.
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|Item Type:||Journal Article|
|Keywords:||Hydrogel contact lens, water content, surface hydration, hand refractometer|
|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 1986 Optometrists Association Australia|
|Deposited On:||19 Nov 2007|
|Last Modified:||10 Aug 2011 13:21|
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