Biomechanics of human optic chiasmal compression: ex vivo experiment and finite element modelling  

作　　者：Xiaofei Wang Andrew J.Neely Neeranjali S.Jain Swaranjali V.Jain Sanjiv Jain Murat Tahtali Gawn G.McIlwaine Christian J.Lueck 

机构地区：[1]Laboratory for Biomechanics and Mechanobiology of Ministry of Education,Beijing Advanced Innovation Centre for Biomedical Engineering,School of Biological Science and Medical Engineering,Beihang University,Beijing,100083,China [2]School of Engineering and Information Technology,University of New South Wales,Canberra,Australian Capital Territory,Australia [3]Department of Neurology,The Canberra Hospital,Canberra,Australian Capital Territory,Australia [4]Faculty of Medicine,University of New South Wales,Kensington,Sydney,New South Wales,Australia [5]Department of Anatomical Pathology,The Canberra Hospital,Canberra,Australian Capital Territory,Australia [6]Queen׳s University Belfast,Belfast,Northern Ireland,UK [7]Belfast Health and Social Care Trust,Belfast,Northern Ireland,UK [8]Australian National University Medical School,Canberra,Australian Capital Territory,Australia [9]Ophthalmic Engineering&Visual Science Laboratory,School of Biological Science and Medical Engineering,Beihang University,Room 424,Building 5,37 Xueyuan Road,Beijing,10083,China

出　　处：《Medicine in Novel Technology and Devices》2022年第1期110-117,共8页医学中新技术与新装备（英文）

基　　金：Supported by National Natural Science Foundation of China(12002025);This study was approved by the ACT Health Human Research Ethics Committee(ETH 1.14.020).

摘　　要：The mechanism of bitemporal hemianopia arising as a result of chiasmal compression is unknown.In this study,we combined an ex vivo experiment and finite element modelling(FEM)to investigate its potential mechanism.A cadaveric human optic chiasm was scanned using micro-CT before and after deformation by inflation of Foley catheter,to simulate tumour growth from beneath.The geometry of the same chiasm was reconstructed and simulated using finite element analysis.Chiasmal deformations were extracted from the simulation and compared with those observed during micro-CT scanning.In addition,nerve fibre models examining variation in local fibre distribution patterns of the chiasm were incorporated to investigate the strain(deformation)distributions of the chiasm at an axonal level.The FEM model matched the micro-CT scans well both qualitatively and quantitatively.Compression of the chiasm induced high strains in the paracentral portions of the chiasm where the crossing optic nerve fibres are located.At an axonal level,the magnitude of strains affecting crossed fibres were greater than those affecting uncrossed fibres.The high strains in the paracentral portions of the chiasm,combined with the differences in strain between crossed and uncrossed nerve fibres,are consistent with a biomechanical explanation for the pattern of visual field loss seen in chiasmal compression.

关 键 词：Bitemporal hemianopia Pituitary tumour CHIASM Finite element modelling Optic nerve fibre 

分 类 号：R318[医药卫生—生物医学工程]