Effect of in vivo and in vitro surface protein deposits on the oxygen permeability of polyhydroxyethylmethacrylate gel contact lenses.

The effect of surface protein deposits on the oxygen permeability of polyhydroxyethylmethacrylate ( polyHEMA ) gel contact lenses was studied using: (1) previously worn lenses with protein deposits accumulated in vivo, and (2) new lenses with protein deposited in vitro. The oxygen permeability (Dk) of the protein-deposited in vivo lenses was determined before and after cleaning, and that of the new lenses before and after in vitro protein deposition. For both groups of lenses, the oxygen permeability did not change significantly after either cleaning (in vivo lenses) or protein deposition (in vitro lenses). It is concluded that surface protein deposits on polyHEMA lenses do not alter the oxygen permeability of the lenses.