Acknowledgements Purpose Results References

Holden and Mertz hypothesized that a minimum oxygen transmissibility (Dk/t) of a lens should be 87±3.3 (barrers/cm) in order to prevent overnight corneal swelling.1 More recently, a value of 125 (barrers/cm) has been proposed as the critical Dk/t of a lens to prevent lens-induced overnight corneal anoxia.2 Studies have shown that silicone hydrogel lenses induce less corneal swelling compared to conventional hydrogel lenses when worn overnight.3-7 This is the first study comparing overnight corneal swelling induced by four different Silicone hydrogel lenses with three different powers