NUS Graduate School for Integrative Science and Engineering, National University of Singapore, Singapore.
Ophthalmic Engineering & Innovation Laboratory, Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.
Br J Ophthalmol. 2021 Dec;105(12):1758-1764. doi: 10.1136/bjophthalmol-2020-318246. Epub 2021 Jan 19.
To assess gaze evoked deformations of the optic nerve head (ONH) in thyroid eye disease (TED), using computational modelling and optical coherence tomography (OCT).
Multiple finite element models were constructed: one model of a healthy eye, and two models mimicking effects of TED; one with proptosis and another with extraocular tissue stiffening. Two additional hypothetical models had extraocular tissue softening or no extraocular tissue at all. Horizontal eye movements were simulated in these models. OCT images of the ONH of 10 healthy volunteers and 1 patient with TED were taken in primary gaze. Additional images were recorded in the same subjects performing eye movements in adduction and abduction. The resulting ONH deformation in the models and human subjects was measured by recording the 'tilt angle' (relative antero-posterior deformation of the Bruch's membrane opening).
In our computational models the eyes with proptosis and stiffer extraocular tissue had greater gaze-evoked deformations than the healthy eye model, while the models with softer or no extraocular tissue had lesser deformations, in both adduction and abduction. In healthy subjects, the mean tilt angle was 1.46°±0.25 in adduction and -0.42°±0.12 in abduction. The tilt angle measured in the subject with TED was 5.37° in adduction and -2.21° in abduction.
Computational modelling and experimental observation suggest that TED can cause increased gaze-evoked deformations of the ONH.
利用计算建模和光学相干断层扫描（OCT）评估甲状腺眼病（TED）中视神经头（ONH）的眼球运动诱发变形。
构建了多个有限元模型：一个健康眼模型，两个模拟 TED 影响的模型；一个模型有眼球突出，另一个模型有眼外组织僵硬。另外两个假设模型具有眼外组织软化或根本没有眼外组织。在这些模型中模拟水平眼球运动。对 10 名健康志愿者和 1 名 TED 患者的原发性注视的 ONH 进行 OCT 成像。在相同的受试者中进行内收和外展眼球运动时记录额外的图像。通过记录“倾斜角”（Bruch 膜开口的相对前后变形）来测量模型和人体受试者中的 ONH 变形。
在我们的计算模型中，眼球突出和眼外组织僵硬的眼睛比健康眼模型具有更大的眼球运动诱发变形，而眼外组织较软或没有眼外组织的模型在内收和外展时变形较小。在健康受试者中，内收时的平均倾斜角为 1.46°±0.25，外展时为-0.42°±0.12。在 TED 患者中测量的倾斜角在 5.37°内收和-2.21°外展。
计算建模和实验观察表明，TED 可引起 ONH 的眼球运动诱发变形增加。
