Experimental Study Of Conjunctival Reconstruction By Amniotic Extracellular Matrix And Conjunctival Extracellular Matrix

Objective To probe the effects of amniotic extracellular matrix and conjunctival extracellular matrix on recovering conjunctival structure and function by repairing conjunctival defects respectively with them, and to provide evidences for rebuilding ocular surface.Methods Modles of conjunctival defects were established in 24 eyes of 12 rabbits. Then the defect in one eye of every rabbit was repaired with amniotic extracellular matrix and another in the other eye was repaired with conjunctival extracellular matrix. After surgery, 12 rabbits were divided randomly into four groups, which were respectively done the pathologic and histologic examinations of transplant tissue by light and electron microscope and conjunctival impression cytology at week 1,2,3 and 5. And all rabbits were observed by slit lamp microscope every other day.Results1. In two groups, all of grafts lived and no dropped or resolved. There were no Complication such as symblepharon ,scar formation and so on.2. Slit lamp microscope observation: In Group amniotic ECM, tissue irritation was mild, while in Group conjunctival ECM tissue rejection occurred early, appeared serious and lasted long.At 5 weeks after transplantation renew conjunction of two groups were similar to normal.3. Impression cytology observation: After surgery, in two groups the number of goblet cells was increasingly larger and the grade of squamous metaplasia gradually lowed. Compared with Group amniotic ECM, in Group conjunctival ECM the degree of squamous metaplasia was lighter and goblet cells was fewer at different times.4. Histopathologic observations: At 1 week,in Group conjunctival ECM regene- rate epithelial cells completely covered the surface of grafts and a lot of inflammatory cells infiltrated, while in Group amniotic ECM the center part of grafts were naked. At 3 weeks, epithelial cells layer of Group conjunctival ECM was thicker than that of Group amniotic ECM.Conclusion1. Amniotic ECM and conjunctival ECM are ideal conjunctival substrates. Am- niotic ECM is more lower on antigenicity and more obvious on the aspect of inflammation inhibition than conjunctival ECM, while conjunctival ECM facilitates the recovery of conjunctival structure and function.