Muñoz Sarmiento Diana Marcela, Rodríguez Montaño Óscar Libardo, Alarcón Castiblancoa Juan David, Cortés Rodríguez Carlos Julio
Grupo de Investigación en Biomecánica, Universidad Nacional de Colombia, Colombia.
Sociedad de Oftalmología Eduardo Arenas Archila, Colombia.
Heliyon. 2023 Feb 11;9(2):e13634. doi: 10.1016/j.heliyon.2023.e13634. eCollection 2023 Feb.
It has been proposed that eye movements could be related to glaucoma development. This research aimed to compare the impact of intraocular pressure (IOP) versus horizontal duction on optic nerve head (ONH) strains. Thus, a tridimensional finite element model of the eye including the three tunics of the eye, all of the meninges, and the subarachnoid space (SAS) was developed using a series of medical tests and anatomical data. The ONH was divided into 22 subregions, and the model was subjected to 21 different eye pressures, as well as 24 different degrees of adduction and abduction ranging from 0.5° to 12°. Mean deformations were documented along anatomical axes and in principal directions. Additionally, the impact of tissue stiffness was assessed. The results show no statistically significant differences between the lamina cribrosa (LC) strains due to eye rotation and IOP variation. However, when assessing LC regions some experienced a reduction in principal strains following a 12° duction, while after the IOP reached 12 mmHg, all LC subzones showed an increase in strains. From an anatomical perspective, the effect on the ONH following 12° duction was opposite to that observed after a rise in IOP. Moreover, high strain dispersion inside the ONH subregions was obtained with lateral eye movements, which was not observed with increased IOP and variation. Finally, SAS and orbital fat stiffness strongly influenced ONH strains during eye movements, while SAS stiffness was also influential under ocular hypertension. Even if horizontal eye movements cause large ONH deformations, their biomechanical effect would be markedly distinct from that induced by IOP. It could be predicted that, at least in physiological conditions, their potential to cause axonal injury would not be so relevant. Thus, a causative role in glaucoma does not appear likely. By contrast, an important role of SAS would be expectable.
有人提出眼球运动可能与青光眼的发展有关。本研究旨在比较眼内压（IOP）与水平转导对视神经乳头（ONH）应变的影响。因此，利用一系列医学测试和解剖学数据，建立了一个包括眼球三层膜、所有脑膜和蛛网膜下腔（SAS）的眼球三维有限元模型。将ONH分为22个子区域，该模型承受21种不同的眼压，以及24种不同程度的内收和外展，范围从0.5°到12°。记录沿解剖轴和主方向的平均变形。此外，还评估了组织刚度的影响。结果表明，由于眼球旋转和IOP变化导致的筛板（LC）应变之间没有统计学上的显著差异。然而，在评估LC区域时，一些区域在12°转导后主应变降低，而在IOP达到12 mmHg后，所有LC子区域的应变均增加。从解剖学角度来看，12°转导后对ONH的影响与IOP升高后观察到的影响相反。此外，眼球侧向运动在ONH子区域内产生了高应变离散，而IOP增加和变化时未观察到这种情况。最后，SAS和眶脂肪刚度在眼球运动期间强烈影响ONH应变，而SAS刚度在高眼压情况下也有影响。即使水平眼球运动导致ONH发生大的变形，其生物力学效应也将与IOP引起的效应明显不同。可以预测，至少在生理条件下，它们导致轴突损伤的可能性不大。因此，在青光眼发病中似乎不太可能起致病作用。相比之下，SAS可能起重要作用。
