INTERLEUKIN-6 IN TEAR FLUID AFTER PHOTOREFRACTIVE KERATECTOMY AND ITSEFFECTS ON KERATOCYTES IN CULTURE

Purpose, To investigate the participation of interleukin-6 (IL-6) afte r photorefractive keratectomy (PRK) and its possible roles and sources in corneal wound healing. Methods, IL-6 levels were measured in the t ear fluids of patients before and after PRK and in conditioned media o f human corneal epithelial cells and keratocytes. Its effects on total collagen and collagen-type synthesis by keratocytes were studied with a H-3-proline incorporation assay and Northern blot analysis. Zymogra phy was used to evaluate the metalloproteinase content in the conditio ned medium of IL-6-stimulated keratocytes. Results, IL-6 is present in the tear fluid samples after photorefractive keratectomy, possibly sy nthesized by epithelial cells and keratocytes. Conclusions, IL-6 stimu lates collagen synthesis in general and collagen type I in particular. Furthermore, it reduces the production of MMP-2, the latent form of t he metalloproteinase, by cultured keratocytes. The results suggest tha t IL-6 might be regarded as a mediator involved in corneal healing aft er excimer laser.