title: Computing the influences of different Intraocular Pressures on the human eye components using computational fluid-structure interaction model.
abstract: BACKGROUND
  Intraocular Pressure (IOP) is defined as the pressure of aqueous in the eye. It has been reported that the normal range of IOP should be within the 10-20 mmHg with an average of 15.50 mmHg among the ophthalmologists. Keratoconus is an anti-inflammatory eye disorder that debilitated cornea unable to reserve the normal structure contrary to the IOP in the eye. Consequently, the cornea would bulge outward and invoke a conical shape following by distorted vision. In addition, it is known that any alterations in the structure and composition of the lens and cornea would exceed a change of the eye ball as well as the mechanical and optical properties of the eye.
  
  
  OBJECTIVE
  Understanding the precise alteration of the eye components' stresses and deformations due to different IOPs could help elucidate etiology and pathogenesis to develop treatments not only for keratoconus but also for other diseases of the eye.
  
  
  METHODS
  In this study, at three different IOPs, including 10, 20, and 30 mmHg the stresses and deformations of the human eye components were quantified using a Three-Dimensional (3D) computational Fluid-Structure Interaction (FSI) model of the human eye.
  
  
  RESULTS
  The results revealed the highest amount of von Mises stress in the bulged region of the cornea with 245 kPa at the IOP of 30 mmHg. The lens was also showed the von Mises stress of 19.38 kPa at the IOPs of 30 mmHg. In addition, by increasing the IOP from 10 to 30 mmHg, the radius of curvature in the cornea and lens was increased accordingly. In contrast, the sclera indicated its highest stress at the IOP of 10 mmHg due to over pressure phenomenon. The variation of IOP illustrated a little influence in the amount of stress as well as the resultant displacement of the optic nerve.
  
  
  CONCLUSIONS
  These results can be used for understanding the amount of stresses and deformations in the human eye components due to different IOPs as well as for clarifying significant role of IOP on the radius of curvature of the cornea and the lens.
authors.affiliation: Department of Mechanical Engineering, Kyushu University, Fukuoka 819-0395, Japan.
authors.forename: Alireza
authors.initials: A
authors.lastname: Karimi
authors.affiliation: Basir Eye Health Research Center, Tehran 14186, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Razaghi
authors.affiliation: Department of Biomechanics, Science and Research Branch, Islamic Azad University, Tehran 755/4515, Iran.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Navidbakhsh
authors.affiliation: Department of Mechanical Engineering, Kyushu University, Fukuoka 819-0395, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Sera
authors.affiliation: Department of Mechanical Engineering, Kyushu University, Fukuoka 819-0395, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kudo
mesh_terms: D000465:Algorithms; D004548:Elasticity; D005123:Eye; D006801:Humans; D021621:Imaging, Three-Dimensional; D007429:Intraocular Pressure / Q000502:physiology*; D007640:Keratoconus; D008954:Models, Biological; D009799:Ocular Physiological Phenomena
keywords: Human eye; Intraocular Pressure; fluid-structure interaction; keratoconus; stresses and deformations