The Determination Of Ⅰ Precollagen On Epithelial Wound Healing And Stromal Remodelling After Excimer Laser Keratectomy In Rat Cornea

Objective To study the changes of corneal I precollagen on rats by Excimer Laser surgery. After comparing the difference of I precollagen content between non-operation area, transparent cornea area and haze area, the time content curve should be made. Making the correlation analysis of the haze area's area and the degree and the precollagen content to further study its secretion, external environment and the processing enzyme content and the active change to provides the powerful theory support.Methods Firstly, the PRK surgery model on rat is established. After the operation, we observe rats'cornea haze forming by the slit lamp microscope every day, and classify the haze level by Seiler's [1] 5 level separate criteria. Rats were killed on preoperative, the first day, the third day, the seventh day, the fifteenth day, the first month, the second month and the third month of operated. After taking out of rats'eyes, we marked the area of haze by needling on the slit lamp microscope, and then fixed the cornea by preserving fluid. Dyeing the collagen by HE technology, we observe the structure of collagen on light microscope. We use mouse anti-goat I precollagen antibody fixation SABC technology to detect and locate corneal I precollagen. Under the light microscope, we observe the change of the distribution and the quantity of corneal I precollange. With the image analysis software, we gather the optical density value of colored I precollagen from non-operation area, transparent cornea area and haze area in the different time. In this way, we can carry out quantitative analysis on I precollagen content using the average optical. Deepens gradually along with time expand its color, and the dying of haze area have the obvious difference with periphery. We test the average optical of corneal I precollagen by image analysis system.Result After 15 days of operation, haze begin to appear. Until later the second months after technique, the grade of haze achieves the highest. The graduation has the obvious relevance with I collagen conten(tr=0.406,p<0.05). Hereafter weakens has the retrogression, but does not drop along with I precollagen's content drops. The changes are obvious after 15 days of operation by HE dyeing, which presented the vacuole, the arrangement disorder of the corneal stroma collagenous fibre. This performance is more obvious in the haze mark place. With transmission electron microscope observation corneal stroma level,we find that collagenous fibre arrange disorder, and the vacuolus is presenting. We use mouse anti-goat I precollagen antibody fixation SABC technology to detect and locate corneal I precollagen. Under the light microscope, we observe that I precollagen mainly appear in the extracellular matrix, not inside cell. The content of I precollagen has not obviously changes in non-operation area and the normal cornea grey level on various time section(p>0.05). After PRK technique, the content of corneal I precollagen starts to increase obviously in the third day(p<0.05). The content of corneal I precollagen elevates gradually along with the time expand, and achieves the high point in the surgery latter two months. The content of corneal I precollagen obvious drop on technique latter 3 months but was still higher than before the surgery, and the first day after the technique(p<0.05). The content of cornealâ… precollagen in the haze area is higher than the non-haze area obviously after the technique, 15th day, the 1st month, the 2nd month, the 3rd month(p<0.05). The content of I precollagen in operation area increase obviously compared the non-operation area, which illust I precollagen participate in cornea's damage repair process. The content carries on along with the repair increases unceasingly. After the repair completes, its content starts to drop. The content of the corneal I precollagen compares non-haze in the haze area obviously to increase, and forms the degree with haze to have the obvious relevance. This indicated that I precollagen exceptionally increases are the substantial clause for haze forms. Possibly it is the most main reason for the arrangement disorder of the corneal collagen and haze formation.Conclusion 1. The quantity of corneal I precollagen increase maybe is one of the major factor. 2. Perhaps it is one of the major cause of indiscriminate construction of collagen, that the process obstacle of I precollagen results abnormal collagen forming. 3. After Excimer Laser Surgery, the corneal I precollagen increases. Which supply emphatic theory support for studying the secrete, external environment and processing enzyme content and active change of the corneal I precollagen. I precollagen is distributed in the normal cornea and the field of operation cornea, but in the normal cornea the content is constant.