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Bayatpour D, Abouali O, Ghaffarieh A, Ahmadi G. In silico investigation of cornea deformation during irrigation/aspiration in phacoemulsification in cataract surgery. Med Eng Phys 2017; 43:77-85. [PMID: 28291699 DOI: 10.1016/j.medengphy.2017.02.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 01/25/2017] [Accepted: 02/12/2017] [Indexed: 10/20/2022]
Abstract
To analyze the stress, strain and displacement of the human cornea under the action of negative intraocular pressure, which occurs during phacoemulsification in cataract surgery, a multidisciplinary approach including biomedical engineering, solid mechanics, numerical analysis, and fluid dynamics was used. Fluid-structure interaction method was implemented using 3-dimensional nonlinear finite element analysis of cornea tissue in conjunction with CFD analysis of anterior chamber fluid flow to study the deformation of the cornea under negative gage pressure during irrigation and aspiration (I/A). The computational model of the eye includes both cornea and sclera. To increase the accuracy of the computational model, both cornea hyperelasticity and thickness variation were included in the analysis. The simulation was performed for both coaxial and bimanual I/A systems with different flow rates. The cornea deformations for various flow rates were evaluated, and the possibility of an unstable anterior chamber was assessed. The results show that the critical pressure in the anterior chamber, which may lead to the surge condition due to buckling of the cornea, is sub-ambient (below zero gauge pressure). Anterior chamber instability occurs at higher volume flow rates for coaxial I/A system compared with that for bimanual system, but the deformation of the cornea is more intense for the bimanual system.
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Affiliation(s)
| | - Omid Abouali
- School of Mechanical Engineering, Shiraz University, Shiraz, Iran.
| | - Alireza Ghaffarieh
- Department of Pathology and Laboratory Medicine, IndianaUniversitySchool of Medicine, Indianapolis, IN, USA
| | - Goodarz Ahmadi
- Aeronautical and Mechanical Engineering Department, Clarkson University, Potsdam, NY, USA
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Nakano CT, Motta AFP, Hida WT, Nakamura CM, Tzelikis PF, Ruiz Alves M, Werner L. Hurricane cortical aspiration technique: one-step continuous circular aspiration maneuver. J Cataract Refract Surg 2014; 40:514-6. [PMID: 24530022 DOI: 10.1016/j.jcrs.2014.01.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 10/24/2013] [Accepted: 11/01/2013] [Indexed: 11/18/2022]
Abstract
UNLABELLED We describe a modification of the original standard radial aspiration technique. The modified technique--hurricane 1-step continuous circular cortical aspiration--has the potential to improve this part of phacoemulsification surgery with benefits in surgical time and possible decreases in fluid, corneal edema, and traction on the zonular fibers through better distribution of tractional forces. The first results were encouraging and without complications. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Celso Takashi Nakano
- From the Department of Ophthalmology (Nakano, Motta, Hida, Nakamura, Tzelikis, Ruiz Alves), School of Medicine of São Paulo, University of São Paulo, Brazil; the John A. Moran Eye Center (Werner), University of Utah, Salt Lake City, Utah, USA
| | - Antonio Francisco Pimenta Motta
- From the Department of Ophthalmology (Nakano, Motta, Hida, Nakamura, Tzelikis, Ruiz Alves), School of Medicine of São Paulo, University of São Paulo, Brazil; the John A. Moran Eye Center (Werner), University of Utah, Salt Lake City, Utah, USA
| | - Wilson Takashi Hida
- From the Department of Ophthalmology (Nakano, Motta, Hida, Nakamura, Tzelikis, Ruiz Alves), School of Medicine of São Paulo, University of São Paulo, Brazil; the John A. Moran Eye Center (Werner), University of Utah, Salt Lake City, Utah, USA
| | - Cristiane Mitie Nakamura
- From the Department of Ophthalmology (Nakano, Motta, Hida, Nakamura, Tzelikis, Ruiz Alves), School of Medicine of São Paulo, University of São Paulo, Brazil; the John A. Moran Eye Center (Werner), University of Utah, Salt Lake City, Utah, USA
| | - Patrick Frensel Tzelikis
- From the Department of Ophthalmology (Nakano, Motta, Hida, Nakamura, Tzelikis, Ruiz Alves), School of Medicine of São Paulo, University of São Paulo, Brazil; the John A. Moran Eye Center (Werner), University of Utah, Salt Lake City, Utah, USA.
| | - Milton Ruiz Alves
- From the Department of Ophthalmology (Nakano, Motta, Hida, Nakamura, Tzelikis, Ruiz Alves), School of Medicine of São Paulo, University of São Paulo, Brazil; the John A. Moran Eye Center (Werner), University of Utah, Salt Lake City, Utah, USA
| | - Liliana Werner
- From the Department of Ophthalmology (Nakano, Motta, Hida, Nakamura, Tzelikis, Ruiz Alves), School of Medicine of São Paulo, University of São Paulo, Brazil; the John A. Moran Eye Center (Werner), University of Utah, Salt Lake City, Utah, USA
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Abouali O, Bayatpour D, Ghaffariyeh A, Ahmadi G. Simulation of flow field during irrigation/aspiration in phacoemulsification using computational fluid dynamics. J Cataract Refract Surg 2011; 37:1530-8. [DOI: 10.1016/j.jcrs.2011.02.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2010] [Revised: 02/16/2011] [Accepted: 02/17/2011] [Indexed: 10/18/2022]
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