Detection of complement regulatory proteins on soft contact lenses

Purpose. To determine whether the regulators of complement activation, decay-accelerating factor (DAF) and CD59, which have been identified on the cornea and conjunctiva and in soluble forms in tears and lacrimal secretions, are transferred to soft contact lenses worn by normal subjects. Methods. Following overnight wear of group 3 extended-wear hydrophilic contact lenses by five normal subjects, we examined the lenses immunohistochemically for decay-accelerating factor (DAF) and CD59, two regulators which interfere with the complement cascade at the C3 and C9 steps, respectively. Results. Both proteins were detected on ail worn lenses but not on controls. Conclusions. These findings raise the question of whether these proteins, as do other contact lens-bound proteins, have deleterious effects, or to the contrary, if they maintain their natural activity, might they have protective functions for contact lens wearers.