Changes in the concentration of secretory immunoglobulin A in tears during post-operative inflammation of the eye.

Twenty-five patients operated for cataract were examined for secretory immunoglobulin A (sIgA) content of tears by an enzyme-linked immunosorbent assay technique. The patients were examined before operation and throughout the post-operative period. The pre-operative level was 795 micrograms/ml, significantly dropping on the first post-operative day to 461 micrograms/ml. Thereafter the level increased to pre-operative value, and finally decreased once more to half the pre-operative level on the 12th post-operative day. The first drop in sIgA concentration is proposed to be a dilution effect by a significantly increased tear volume as determined by the Schirmer test. The reason for the second drop is up to now unexplained, but might be the result of an exhaustion of the sIgA production by the tear glands.