PURPOSE: To investigate the biomechanical response of the optic nerve head (ONH) connective tissues to IOP elevation in three pairs of monkey eyes in which one eye had early experimental glaucoma (EG). METHODS: A serial imaging technique was used to reconstruct the ONH and peripapillary sclera of three pairs of unilateral EG eyes fixed at 10 mm Hg. Eye-specific finite element models of the posterior pole were constructed with inhomogeneous material properties defined for the lamina cribrosa (LC) based on local connective tissue volume fraction (CTVF) and predominant LC beam orientation. These models were used to simulate an IOP increase from 10 to 45 mm Hg. A laminar material constant was varied to produce a range of LC displacements and scleral canal expansions, and the associated LC stress and strain were characterized. RESULTS: The models suggest that the LC of normal and EG eyes can deform posteriorly or anteriorly when the LC material stiffness is low or high, respectively. Scleral canal expansion was generally, but not always, reduced in EG eyes. Strains in the EG eye were similar to or lower than those in the contralateral eye for the same average LC displacement and increased when the LC was more plaint. Laminar stresses were consistently lower in the EG eye, regardless of LC stiffness. CONCLUSIONS: Connective tissue remodeling in EG alters the biomechanical response of the LC to IOP elevation in an eye-specific manner. The models indicated that the LC tissues in EG eyes were more plaint than those in the contralateral normal eyes in two of three monkeys.
PURPOSE: To investigate the biomechanical response of the optic nerve head (ONH) connective tissues to IOP elevation in three pairs of monkey eyes in which one eye had early experimental glaucoma (EG). METHODS: A serial imaging technique was used to reconstruct the ONH and peripapillary sclera of three pairs of unilateral EG eyes fixed at 10 mm Hg. Eye-specific finite element models of the posterior pole were constructed with inhomogeneous material properties defined for the lamina cribrosa (LC) based on local connective tissue volume fraction (CTVF) and predominant LC beam orientation. These models were used to simulate an IOP increase from 10 to 45 mm Hg. A laminar material constant was varied to produce a range of LC displacements and scleral canal expansions, and the associated LC stress and strain were characterized. RESULTS: The models suggest that the LC of normal and EG eyes can deform posteriorly or anteriorly when the LC material stiffness is low or high, respectively. Scleral canal expansion was generally, but not always, reduced in EG eyes. Strains in the EG eye were similar to or lower than those in the contralateral eye for the same average LC displacement and increased when the LC was more plaint. Laminar stresses were consistently lower in the EG eye, regardless of LC stiffness. CONCLUSIONS: Connective tissue remodeling in EG alters the biomechanical response of the LC to IOP elevation in an eye-specific manner. The models indicated that the LC tissues in EG eyes were more plaint than those in the contralateral normal eyes in two of three monkeys.
Authors: J Crawford Downs; Richard A Blidner; Anthony J Bellezza; Hilary W Thompson; Richard T Hart; Claude F Burgoyne Journal: Invest Ophthalmol Vis Sci Date: 2002-07 Impact factor: 4.799
Authors: J C Downs; M E Ensor; A J Bellezza; H W Thompson; R T Hart; C F Burgoyne Journal: Invest Ophthalmol Vis Sci Date: 2001-12 Impact factor: 4.799
Authors: J Crawford Downs; J K Francis Suh; Kevin A Thomas; Anthony J Bellezza; Claude F Burgoyne; Richard T Hart Journal: J Biomech Eng Date: 2003-02 Impact factor: 2.097
Authors: Michael A Kass; Dale K Heuer; Eve J Higginbotham; Chris A Johnson; John L Keltner; J Philip Miller; Richard K Parrish; M Roy Wilson; Mae O Gordon Journal: Arch Ophthalmol Date: 2002-06
Authors: Michael D Roberts; Yi Liang; Ian A Sigal; Jonathan Grimm; Juan Reynaud; Anthony Bellezza; Claude F Burgoyne; J Crawford Downs Journal: Invest Ophthalmol Vis Sci Date: 2009-08-20 Impact factor: 4.799
Authors: Ian A Sigal; Richard A Bilonick; Larry Kagemann; Gadi Wollstein; Hiroshi Ishikawa; Joel S Schuman; Jonathan L Grimm Journal: Invest Ophthalmol Vis Sci Date: 2012-05-04 Impact factor: 4.799
Authors: Ian A Sigal; Hongli Yang; Michael D Roberts; Jonathan L Grimm; Claude F Burgoyne; Shaban Demirel; J Crawford Downs Journal: Invest Ophthalmol Vis Sci Date: 2011-11-21 Impact factor: 4.799
Authors: Hongli Yang; Hilary Thompson; Michael D Roberts; Ian A Sigal; J Crawford Downs; Claude F Burgoyne Journal: Invest Ophthalmol Vis Sci Date: 2011-01-21 Impact factor: 4.799
Authors: Ian A Sigal; Hongli Yang; Michael D Roberts; Claude F Burgoyne; J Crawford Downs Journal: Invest Ophthalmol Vis Sci Date: 2011-03-30 Impact factor: 4.799
Authors: Ian A Sigal; Jonathan L Grimm; Ning-Jiun Jan; Korey Reid; Don S Minckler; Donald J Brown Journal: Invest Ophthalmol Vis Sci Date: 2014-01-02 Impact factor: 4.799
Authors: Hongli Yang; Galen Williams; J Crawford Downs; Ian A Sigal; Michael D Roberts; Hilary Thompson; Claude F Burgoyne Journal: Invest Ophthalmol Vis Sci Date: 2011-09-09 Impact factor: 4.799
Authors: Ian C Campbell; Baptiste Coudrillier; Johanne Mensah; Richard L Abel; C Ross Ethier Journal: J R Soc Interface Date: 2015-03-06 Impact factor: 4.118
Authors: Howard Lockwood; Juan Reynaud; Stuart Gardiner; Jonathan Grimm; Vincent Libertiaux; J Crawford Downs; Hongli Yang; Claude F Burgoyne Journal: Invest Ophthalmol Vis Sci Date: 2015-02-03 Impact factor: 4.799
Authors: Jessica E Goetz; Nicole M Kunze; Erin K Main; Daniel R Thedens; Thomas E Baer; Ericka A Lawler; Thomas D Brown Journal: Ann Biomed Eng Date: 2013-04-24 Impact factor: 3.934