title: Biomechanics of Corneal Ring Implants.
abstract: OBJECTIVE
  To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus.
  
  
  METHODS
  The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant designs. The strengthening factor is a measure of the amount of strengthening of the cornea induced by the implant.
  
  
  RESULTS
  For ring segments and incomplete rings, sf = 1.0, which indicates that these implants are not able to strengthen the cornea. The intracorneal continuous complete ring (MyoRing) has a strengthening factor of up to sf = 3.2. The MyoRing is, therefore, able to strengthen the cornea significantly.
  
  
  CONCLUSIONS
  The result of the presented biomechanical analysis of different ring-shaped corneal implant designs can explain the different postoperative clinical results of different implant types in myopia and keratoconus.
authors: *Gutsehen Eye Center, Ybbs, Austria; and †Department of Ophthalmology, Medical University of Innsbruck, Innsbruck, Austria.
authors: Albert
authors: A
authors: Daxer
mesh_terms: D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D003315:Cornea / Q000503:physiopathology*; D003319:Corneal Stroma / Q000601:surgery*; D004548:Elasticity / Q000502:physiology*; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology* / Q000601:surgery; D008962:Models, Theoretical; D009216:Myopia / Q000503:physiopathology* / Q000601:surgery; D019904:Polymethyl Methacrylate; D019736:Prostheses and Implants; D019919:Prosthesis Implantation
chemical_list: D001672:Biocompatible Materials; D019904:Polymethyl Methacrylate