Local oxygen transmissibility of disposable contact lenses.

Abstract

AIM: Despite global standardisation in measurement of oxygen transmissibility (Dk/t), in our clinic we continue to see limbal vasculature changes in patients wearing some disposable lenses. The use of central Dk/t as a simple designator of a contact lens oxygen performance has clearly failed, it being acknowledged as often unrelated to the oxygen performance of the lens periphery. This study investigates a new criterion for contact lens oxygen transmissibility, the local Dk/t. METHOD: The study measured 20 spherical disposable lens brands (power range: -15.00 to +8.00 D) and 8 toric lens brands (power range: -8.00 to +4.00 D sphere, with a -1.00 D/-1.25 D x 180). An electro-mechanical gauge ..