To develop a better clinical application of the epikeratoprosthesis it is important to find the suitablesize of the artificial corneal epithelium, the way of the application of adhesive and the way of complete removal of the epithelium. The authors have an animal experiment basing on above various factors using isobutyl cyanoacrylate as an adhesive and methyl methacrylate as a material of the artificial corneal epithelium. Also we have successfuly performed epikeratoprosthesis operations in five cases of severe bullous keratitis patients. In the animal experimental group, Group 2(isobutyl cyanoacrylate was painted 2 mm broad along the periphery of the lens) showed markedly less extrusion of the artificial corneal epithelium than that of the Group 1 (adhesive was painted 1 mm broad). However, earlier appearance and more frequent incidence of the neovascularization of the cornea were noted in Group 2. On the other hand the result of the clinical 5 cases of the bullous keratitis was excelIent and there was no complications such as extrusion, infection and marked neovassularization for to 9 months, postoperative observation. On the basis of the data obtained from the series of clinical and experimental studies, it was revealed that the epikeratoprosthesis (artificial corneal epithelium) was effective to control the various diseased conditions of the corneal epithelium without significant complication.
Adhesives ; Animal Experimentation ; Bucrylate ; Cornea ; Cyanoacrylates ; Epithelium ; Epithelium, Corneal ; Hand ; Humans ; Incidence ; Keratitis ; Paint

It is well known that the corneal stroma will swell when it is exposed to an aqueous solution or water in vitro, or when the limiting layers are removed in vivo. These in vivo experiments are concerned with the measurement and comparisons of corneal swelling after destruction of either of its layers (epithelium, endothelium and Descemet's membrane) and of reduction of corneal swelling with the application of epikeratoprosthesis (EKP). MATERIALS AND METHODS: Adult albino rabbits weighing 2-3kg each were used throughout these experiments. To remove the limiting layers, the rabbit was anesthesized with 0.5% pontocaine topical in epithelium removal group and nembutal systemically in another groups, and the epithelium was removed with gauze (Kim et ai, 1971) and the endothelium or/and Descemet's membrane was carefully removed with a specially bent hypodermic needle (Maurice and Giardini, 1951) under the aid of slit-lamp biomicroscope with high magnification. Suspicious cases were confirmed by inspection of sections of the excised cerneal tissues under the microscope after end day of experiments. The changes of corneal thickness were measured with the Mishima-Hedbys modified pachometer which was mounted on Haag Streit 900 slit-lamp. And EKP was made from the material of methylmethacrylate (Kaufman type), and its periphery was painted one mm broad with isobutyl cyanoacrylate as an adhesive. RESULTS AND SUMMERY: 1. The mean central corneal thickness of 48 normal rabbit eyes was 0.409mm +/- 0.005(S.E.) 2. The average rate of increase was initially about 0.4% of the thickness per minute for the epithelium, 0.7-0.9% per minute for the endothelium and endothelium plus Descemet's membrane, and 1.2% per minute for the whole layers. 3. After the removal of the epithelium the cornea swelled on the average to one half its thickness until after about 48 hrs and then returned its normal thickness with epithelium regrowth. 4. A significant difference was not found between the endothelium removal and the endothelium plus Descemet's membrane removal groups, and the maximal swelling of these was a little more of double of its original thickness. 5. After the removal of the epithelium, the endothelium and Descemet's membrane the corneal stroma swelled over 3 times of its original thickness after 24 hrs. 6. With the application of EKP on the bared stroma, its swelling could be limited under a double of its original thickness, and EKP treatment produced corneal thickness reductions of approximately 50% in early to about 100% in late in comparing with the whole layers removal group.
Adhesives ; Adult ; Bucrylate ; Cornea ; Corneal Stroma ; Descemet Membrane ; Endothelium ; Epithelium ; Humans ; Methylmethacrylate ; Needles ; Paint ; Pentobarbital ; Rabbits ; Tetracaine