| When limbal stem cells mail1taining corneal epithelial renewal were irreversiblydestroyed, severe ocular surface damage might occur which was characterized bypersistent epithelial defects, corneal stromal melting, corneal neovascuIarization withscarring and conjunctival epithelial ingrowth. These manifestations were tota1Iycalled ocular surface disorder.The treatment for ocular surface disorder was arduous. Conservative therapyand traditional penetrating or lamellar keratoplasty had poor curative effect. By theend of 1970's, people understood that ocular surface disorder may be associatedwith abnormal corneaI epithelium. In l977 Thoft first reported auto-conjunctivatransplantation fOr ocular surface disorder and got partial success. After that,keratoepithelioplasty auto-limbal transplantation and allo-limbal transplantationemerged one after another which perfected treatment for ocular surface disorderRecently, a new operation calIed amniotic membrane transplantation wasperformed for ocuIar surface disorder. According to documents, it had partialcurative effects on some ocular surface disorder including recurrent pterygium, acutethermal/chemical-burned eye, severe burned eye with proliferating scarring andsome chronic inflammation. HoweveF, up to today, there were still many questionson mechanism of amniotic membrane transpIantation for ocuIar surface disorder,what's the rational choice oftransplantation types and effects of amniotic epitheliumon corneal re-epitheIization. In order to expIain effects of different amnioticmembrane transplantation types on success ratio of operation and improving ocularsurface disorder, and effects of amniotic epithelium on corneal re-epithelization invivo, we performed a study through a alkili-burn rabbit eye model.Snbjects and MethodsRabbits were used for alkili-burn eye model. According to Tseng's method, theprocedure was performed by lameIlar removal of Iimbal area combined with cornealsodium hydroxide burn. After preparation of models, three kinds of amnioticmembrane transplantation were performed which included mesenchymal-side down,mesenchymal-side up and denuded amniotic membrane transplantation.Post-operation, recorded corneal re-epithelizative procedure. And half a month lateF,eva1uated the degree of corneal neovascu1arization, and corneal epithelialconjunctivalization by impression cytology examination. Also took specimens forhistology examination including HE, PAS and Masson trichrome stain.Resultsl.Alldli-burn eye modelThere were l8 rabbits 34 eyes for the experiment. During feeding, 4 rabbits (8eyes) died. The residual 26 alkili-burn eyes accomplished corneal epithelization in36.85t9.26 days. Finished models showed severe comeal opacity, severe cornealneovascularization and scarring. Corneal impression cytology examination indicatedcorneal surface conjunctivalization. Histology examination (l model) indicatedabnormal corneal epithelium which arranged mussily, distortion of stromal collagen,invading of vascular and infiltration of inflammative cel1s.2.Different type's amniotic membrane transplantationThe residuaI l3 rabbits 25 modeIs were divided into three groups fOr differenttype's amniotic membrane transplantation: mesenchymal-side down 9 eyes,mesenchymal-side up 9 eyes and denuded amniotic membrane 7 eyes. Duringoperation and post-operation 6 rabbits (l2 eyes) died. Only 7 rabbits l3 eyescompleted the whoIe experiment which included mesenchymal-side down 5 eyes,mesenchymal-side up 5 eyes and denuded amniotic membrane 3 eyes. Duringoperation aIl residual eyes had no complication. Post-operation also no graftdetachment, infection and so on occurred.3.Corneal re-epithelizationAfter different type's amniotic membrane transplantation, alI corneasre-epithelizated steady and progressively. The group of mesenchymal-side downaccomplished re-epithelization in 8.6fl.52 days. The groups of mesenchymal-sideup and de... |
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