In collaboration with Payame Noor University and Iranian Society of Physiology and Pharmacology

Document Type : Article

Authors

Abstract

Abstract
The purpose of this project was to study the effect of intraocular pressure (IOP) stress on the cross section of the optic nerve. Specifications for the dimensional model based on a digital image of a person's eyes to the inner radius of the eye: 12 mm, sclera thickness mm 0.8 and cross section optic nerve: a circle of radius of 1.75 mm was done by the intraocular pressure to 15 mm Hg or 2 Kpa was considered.Using this model considers stress as a side effect placed on the optic nerve in an arbitrary and disparate examination. Within the two different kinds of models, both the sclera and the nerve are considered the properties of each from theanalysis softwareis incorporated. Utilizing software with element solid 95 for the analysis can create a whole model grid analysis, and the model is intended to be an isotropic model.The model results showed the effects of intraocular pressure and stress levels in the central area of ​​the sclera. The surrounding area around the nerve is greater and the surrounding area of the nerve level is lower than the range. The damages created the eyes as a result of the upward pressure first started from the surrounding area of the eye and eventually, the function of the nerve is destroyed and because these areas are very sensitive, to have knowledge of the change in tension is very important for us. Even slight pressure can cause applied tension to the optic nerve, leading to nerve damage that becomes irreparable.
 

Keywords

Abert & Jakobeic.; (2000) Principles and practice of ophthalmology, Forth edition, Philadelphia, Pensilvania, Saunders, 2663-2676.
Anthony, J.; Bellezza Richard T.; Hart Claude, F.; (2000) Burgoyne The Optic Nerve Head as a Biomechanical Structure: Initial Finite Element Modeling Investigative Ophthalmology & Visual Science, 41(10). Copyright © Association for Research in Vision and Ophthalmology 2991.
Britton, RJ.; Drance, SM.; Schulzer, M.; Douglas, GR.; Mawson, DK.; (1987) The area of the neuroretinal rim of the optic nerve in normal eyes. Am J Ophthalmol, 103: 497-504.
Dongqi, H.; Zeqin, R.; (1999) A biomathematical model for pressure-dependent lamina cribrosa behavior. J Biomech, 32: 579-584.
Hayreh, SS.; (1974) Pathogenesis of cupping of the optic disc. Br J Ophthalmol, 58: 863-76.
Jonas, JB.; Gusek, GC.; Guggenmoos–Holzmann, I.; Naumann, GOH.; (1988) Size of the optic nerve scleral canal and comparison with intravital determination of optic disc dimensions. Graefes Arch Clin Exp Ophthalmol, 226: 213-215.
Quigley, HA.; Brown, AE.; Morrison, JD.; Drance, SM.; (1990) The size and shape of the optic disc in normal human eyes. Arch Ophthalmol, 108: 51-57.
Timoshenko, SP.; Goodier, JN.; (1970) Theory of Elasticity. 3rded. New York: McGraw–Hill.
Yablonski, ME.; Asamoto, A.; (1993) Basic sciences in clinical glaucoma: hypothesis concerning the pathophysiology of optic nerve damage in open angle glaucoma. J Glaucoma, 2: 119-127