The Concentration Of EGF,TGF-β₁ And IL-1α In Tears After PRK And The Expression Of Their Receptors In Corneal Epithelial Cells

Excimer laser photorefractive keratectomy (PRK) is an exciting refractive surgery for its excellent predictability, stability, effectiveness and safeness. In the past years, it has been accepted by ophthalmic surgeons and patients of myopia and astigmatism. Just like other operations, it possesses some special complications to be resolved, such as myopia regression and haze. With the use of LASIK procedure, such complications are reduced to some extends. Cytokines are a group of active and multi-functional peptides, which have been studied by many scholars. Corneal wound immerses in tears after PRK, where cytokins has been found, they must have effect on the wound healing, then effect the operative results. Whether there are variations of the concentration of cytokines in tears or not, the regularity of variation and the relationship between the concentration and the refractive condition are the questions to be resolved in this research.ELISA method was utilized to measure the concentration of EGF> TGF- P i and IL-1 a in tears before operation, the 1st, 2nd, 10th and 30th day postoperatively, variance analysis was used to treat the data. ABC method and indirect immunofluoreince method was chosen to detect the protein expression of the main receptors from these three kinds of cytokines. The results are as follows:1. EGF in tears remains a constant level before and after operation, maybe the main function of EGF is to maintain the hemogenesis of cells.2. TGF-P i in tears decreased in the 1st day postoperatively, then recovered on the 2nd day, we thought that the variation were related to the cellproliferation, after further analysis we found that the decrease only appeared in moderate and low myopia group. And the concentration of TGF- 3 | in moderate and low myopia group was lower than that of high myopia on the 1st , 2nd and 30th day postoperatively with no significant differences. We postulate that the higher concentration of TGF- 3 i in high myopia may be related to the deeper keratectomy and the more obvious corneal stromal healing. The higher concentration of TGF- 3 i in tears of high myopia may have effect on haze and regression.3. There were no significant differences between pre and postoperative IL-1a in tears, the surgical trauma may not affect the concentration of this kind of cytokine.4. ABC method and immunofluoreince method have all conformed the protein expression of the main receptors of these cytokines, the intensity was EGFR> IL-1R I >TGF3 R I .The healing of the cornea after PRK is a complex procedure, among which many details are still unknown, haze and regression are also the results of many factors. Cytokines may only take part effect. The objective of this research is to find the regularity of the changes of cytokines in tears in order to find the methods to inhibit haze and regression of myopia.