The concentration of lactoferrin in tears during post-operative ocular inflammation.

Tear concentration of lactoferrin (LF) was measured by an ELISA technique and followed in 25 patients undergoing cataract surgery. The pre-operative concentration of LF in tears was 773 +/- 60 micrograms/ml (+/- SE) (range: 407-1514 micrograms/ml). On the first day following surgery, there was a significant decrease in tear LF concentration to 377 +/- 45 micrograms/ml followed by a gradual return to the initial value during a post-operative observation period of twelve days. There was an inverse linear relationship between the LF concentration and the tear secretion rate measured by a modified Schirmer I test (1 min) suggesting a constant LF secretion rate by the tear glands. The contribution of LF from neutrophils to the tear fluid seems to be of minor importance. Since LF has known antibacterial and anti-inflammatory effects, our results may contribute to a further understanding of the microbial vulnerability or resistance of the eye following surgical procedures.