Experimental research on implantation of β-TCP/PVA keratoprostheses into alkali-burned cornea in rabbit

Abstract

Objective To evaluate the biocompatibility of β-TCP/PVA keratoprosthesis and its therapeutic effects on the alkali-burned cornea in rabbit.Methods Firstly the models of alkali-burned cornea were induced by putting the filter paper dipped in 1 mol/L NaOH solution on whole cornea of left eyes in 10 New Zealand white rabbits.β-TCP/PVA keratoprosthesis was implanted into these model cornea by two stages.At stage Ⅰ,a superior half-thickness dissection was made from sclera,1.5 mm posterior to the limbus,extended into the cornea and formed an intralamellar pocket,the superior flap was retracted inferiorly and then a 3 mm central opening was created.The device was implanted into the pocket,centering the optic over the posterior opening.After 3 months,stage Ⅱ surgery was performed to expose the optic by removing the central lamella.The recepient cornea and anterior segment findings were clinically observed and evaluated.The dissected corneal tissues were examined pathologically.Results All the keratoprosthesis remained in situ after stage Ⅰ procedure.Comeal perforation caused by inflammatory occurred in No.4 rabbit 4 weeks after stage Ⅰ.The diffuse white posterior membrane was found in No.2 eye and the anterior membrane was seen in No.7 operative eye several weeks after stage Ⅱ surgery.No.9 rabbit died from a diarrhea.Others,implants had been retained,with no severe complications,such as extrusion,stromal malting or aqueous leakage.The intraocular pressure of all eyes was just in normal range.Fibroblasts migration into the skirt of the implants was found.The normal anatomical structure in implanted eyes was noted by anterior segment OCT.Conclusion β-TCP/PVA keratoprosthesis has good tissue biocompatibility,its skirt is helpful to fibroblasts migration.It is predicted that the device will has potential application prospects on the solution for corneal blindness in the future. Key words: Keratoprosthesis ; Hydrogel ; Keratoplasty; Biocompatibility, tissue