The concentration of lysozyme and secretory IgA in tears from healthy persons with and without contact lens use

. A comparison of tear lysozyme and tear secretory IgA, determined by micropipette sampling and immunoassay technique, between 18 long-term contact lens wearers (median age 35 years, median lysozyme concentration 1.93 g/l, median IgA concentration 0.72 g/l) and 42 non-contact lens wearers (median age 41 years, median lysozyme concentration 2.21 g/l, median IgA concentration 2.42 g/l) disclosed a significant decrease (P 0.05). The duration of lens wear was 8.5 years in average ranging from 1 to 23 years. These findings of decreased secretory IgA might partly explain the fact that contact lens wearers are more exposed to infectious corneal and conjunctival complications than non-contact lens wearers.