PURPOSE: To determine the tear oxygen tension under a variety of conventional and silicone hydrogel contact lenses in human subjects. METHODS: Three hydrogel and five silicone hydrogel lenses (Dk/t = 17 to 329) were coated on the back surface with an oxygen sensitive, bovine serum albumin-Pd meso-tetra (4-carboxyphenyl) porphine complex (BSA-porphine). Each lens type was placed on the right eye of 15 non-contact lens wearers to obtain a steady-state open eye tear oxygen tension using oxygen sensitive phosphorescence decay of BSA-porphine. A closed-eye oxygen tension estimate was obtained by measuring the change in tear oxygen tension after 5 min of eye closure. In separate experiments, a goggle was placed over the lens wearing eye and a gas mixture (PO2 = 51 torr) flowed over the lens to simulate anterior lens oxygen tension during eye closure. RESULTS: Mean open eye oxygen tension ranged from 58 to 133 torr. Closed eye estimates ranged from 11 to 42 torr. Oxygen tension under the goggle ranged from 8 to 48 torr and was higher than the closed eye estimate for six out of the eight lenses, suggesting that the average closed eye anterior lens surface oxygen tension is <51 torr. For Dk/t >30, the measured tear oxygen tension is significantly lower than that predicted from previous studies. CONCLUSIONS: The phosphorescence decay methodology is capable of directly measuring the in vivo post lens PO2 of high Dk/t lenses without disturbing the contact lens or cornea. Our data indicate that increasing Dk/t up to and beyond 140 continues to yield increased flux into the central cornea.
PURPOSE: To determine the tear oxygen tension under a variety of conventional and silicone hydrogel contact lenses in human subjects. METHODS: Three hydrogel and five silicone hydrogel lenses (Dk/t = 17 to 329) were coated on the back surface with an oxygen sensitive, bovine serum albumin-Pd meso-tetra (4-carboxyphenyl) porphine complex (BSA-porphine). Each lens type was placed on the right eye of 15 non-contact lens wearers to obtain a steady-state open eye tear oxygen tension using oxygen sensitive phosphorescence decay of BSA-porphine. A closed-eye oxygen tension estimate was obtained by measuring the change in tear oxygen tension after 5 min of eye closure. In separate experiments, a goggle was placed over the lens wearing eye and a gas mixture (PO2 = 51 torr) flowed over the lens to simulate anterior lens oxygen tension during eye closure. RESULTS: Mean open eye oxygen tension ranged from 58 to 133 torr. Closed eye estimates ranged from 11 to 42 torr. Oxygen tension under the goggle ranged from 8 to 48 torr and was higher than the closed eye estimate for six out of the eight lenses, suggesting that the average closed eye anterior lens surface oxygen tension is <51 torr. For Dk/t >30, the measured tear oxygen tension is significantly lower than that predicted from previous studies. CONCLUSIONS: The phosphorescence decay methodology is capable of directly measuring the in vivo post lens PO2 of high Dk/t lenses without disturbing the contact lens or cornea. Our data indicate that increasing Dk/t up to and beyond 140 continues to yield increased flux into the central cornea.
Authors: Oliver D Schein; John J McNally; Joanne Katz; Robin L Chalmers; James M Tielsch; Eduardo Alfonso; Mark Bullimore; Denis O'Day; Joseph Shovlin Journal: Ophthalmology Date: 2005-12 Impact factor: 12.079
Authors: Robin L Chalmers; John J McNally; Oliver D Schein; Joanne Katz; James M Tielsch; Eduardo Alfonso; Mark Bullimore; Denis O'Day; Joseph Shovlin Journal: Optom Vis Sci Date: 2007-07 Impact factor: 1.973
Authors: Paola Ceroni; Artem Y Lebedev; Enrico Marchi; Min Yuan; Tatiana V Esipova; Giacomo Bergamini; David F Wilson; Theresa M Busch; Sergei A Vinogradov Journal: Photochem Photobiol Sci Date: 2011-03-15 Impact factor: 3.982
Authors: Vicente Compañ Moreno; Marcel Aguilella-Arzo; Roxana M Del Castillo; Francisco J Espinós; Luis Felipe Del Castillo Journal: J Optom Date: 2021-02-13