Biomaterial Database

Computer modeling of wound gape following radial keratotomy. 1992

M R Sawusch, and P J McDonnell

Department of Ophthalmology, University of Southern California School of Medicine, Los Angeles.

BACKGROUND The edges of radial keratotomy incisions remain separated by epithelium or new collagen. To determine if the amount of gape of the incision edges agrees with the induced corneal flattening, two mathematical models of the cornea were studied. METHODS A finite element model of the eye was constructed; radial incisions through Bowman's membrane and stroma were simulated, as well as incisions confined to the stroma but not involving Bowman's or Descemet's membranes. Geometrical calculations were also performed in a second morphologic model of a spherical shell. RESULTS The finite element and geometrical models agree closely on the corneal curvature change for a given incision gape. Both models predict that linear intrastromal incisions that do not involve Bowman's layer would not produce significant corneal flattening. CONCLUSIONS Corneal flattening after radial keratotomy is closely related to incision gape, mediated through structural weakening of the cornea. Purely intrastromal radial incisions, as might be created with Nd:YAG lasers, prevent wound gape and would not appear to be a promising technique for flattening the cornea.

UI	MeSH Term	Description	Entries
D007646	Keratotomy, Radial	A procedure to surgically correct REFRACTIVE ERRORS by cutting radial slits into the CORNEA to change its refractive properties.	Radial Keratotomy,Keratotomies, Radial,Radial Keratotomies
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D003198	Computer Simulation	Computer-based representation of physical systems and phenomena such as chemical processes.	Computational Modeling,Computational Modelling,Computer Models,In silico Modeling,In silico Models,In silico Simulation,Models, Computer,Computerized Models,Computer Model,Computer Simulations,Computerized Model,In silico Model,Model, Computer,Model, Computerized,Model, In silico,Modeling, Computational,Modeling, In silico,Modelling, Computational,Simulation, Computer,Simulation, In silico,Simulations, Computer
D003315	Cornea	The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)	Corneas
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014945	Wound Healing	Restoration of integrity to traumatized tissue.	Healing, Wound,Healings, Wound,Wound Healings