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 less than 0.01) of secretory IgA in the contact lens group. The decrease of secretory IgA was associated (P less than 0.01) with the presence of deposits on lens surface. No differences in lysozyme concentration was found between the two groups (P greater than 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.