The Experimental Study Of One-piece P(HEMA) Keratoprosthesis Implanted Into Alkali Burned Rabbit Corneas

Objective: We developed two new types one-piece keratoprosthesis(KPro) made of P(HEMA)(KProI and KProII). The aim of this study was to evaluate biological response to the porous P(HEMA) material as skirt of one-piece Kpro and also to assess the long term clinical outcomes of KProI and KPro II implanted to alkali burned rabbit coraeas(including Kpro designs,operative methods and compalications) Methods: By taking use of polymer swelling phenomenon, mass polymerization and NaCl particles, artificial cornea with an optical region surrounded by porous skirt was fabricated. One biocompatible methods was introduced to enhance the mechanical property of porous skirt. The porous discs of P(HEMA) were inserted into the lamellar pocket of twleve alkali-burned corneas and the corneas were observed clinically , histologically and ultrastructurally at various time. Two KProI and six KProII were implanted in alkli burned corneas, and followed up to 62.5d(17d-108d). Results: By two weeks after impantation fibroblast cells and deposion of collagens were found in the pores of the P(HEMA) dics.The fibroblasts aroundand in the pores looked healthy and functionally active by TEM.No calcification was seen in all specimens.Both of the porous discs and one-piece KPros have been retained during the experiment without severe complications such as cataract, retinal detachment and extrusion. Retroprosthetic membrane occurred in KProI(one case).Synechia was seen in almost one-piece Kpros implanted animals.Conclusion:P(HEMA) material is suitable for making one-piece KPros with low complications.Its flexibility and good qualities allowed control of intraoperative sutures.The new Kpros have shown advantages,especially in operative procedures.The preliminary results were satisfactory.