The Dk project: an interlaboratory comparison of Dk/L measurements.
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).
Holden
B A
BA
Cornea and Contact Lens Research Unit, School of Optometry, University of New South Wales, Australia.
Newton-Howes
J
J
Winterton
L
L
Fatt
I
I
Hamano
H
H
La Hood
D
D
Brennan
N A
NA
Efron
N
N
D003261:Contact Lenses; D008422:Materials Testing; D008433:Mathematics; D010100:Oxygen; D010539:Permeability; D011048:Polarography; D012044:Regression Analysis
D010100:Oxygen