title: The Dk project: an interlaboratory comparison of Dk/L measurements.
abstract: The oxygen transmissibilities (Dk/L) of a set of 48 contact lenses made from 8 different materials were measured by 4 laboratories. The L/Dk measurements from each laboratory were compared and correlated. Samples which were not masked with a fixed front surface aperture during measurement were corrected for edge effects. This paper shows that provided L/Dk is calculated for each lens using the same technique and Dk is derived using a graphical method of calculation, similar results can be obtained by all laboratories. However, the agreement was less good for materials of Dk greater than 70 x 10(-11) (cm2/s) (ml O2/ml x mm Hg).
authors.affiliation: Cornea and Contact Lens Research Unit, School of Optometry, University of New South Wales, Australia.
authors.forename: B A
authors.initials: BA
authors.lastname: Holden
authors.forename: J
authors.initials: J
authors.lastname: Newton-Howes
authors.forename: L
authors.initials: L
authors.lastname: Winterton
authors.forename: I
authors.initials: I
authors.lastname: Fatt
authors.forename: H
authors.initials: H
authors.lastname: Hamano
authors.forename: D
authors.initials: D
authors.lastname: La Hood
authors.forename: N A
authors.initials: NA
authors.lastname: Brennan
authors.forename: N
authors.initials: N
authors.lastname: Efron
mesh_terms: D003261:Contact Lenses; D008422:Materials Testing; D008433:Mathematics; D010100:Oxygen; D010539:Permeability; D011048:Polarography; D012044:Regression Analysis
chemical_list: D010100:Oxygen