The iris plays an important role in certain types of glaucoma, including primary angle-closure glaucoma and pigmentary glaucoma. Iris mechanics are also important in influencing trabecular meshwork deformation in response to intraocular pressure changes in some animal species. Although mice are widely used to study ocular disease, including glaucoma, the in vivo biomechanical properties of the murine iris are unknown. Thus, the primary objective of this study was to estimate murine iris biomechanical stiffness. We used optical coherence tomography (OCT) images of the anterior segment of living mice (n = 13, age = 7.3 ± 3.2 [mean ± SD] months) at sequentially increasing IOP levels, observing IOP-dependent iris deformations. We then used an inverse finite element model to predict iris deformations under the same conditions, estimating iris stiffness by maximizing agreement between OCT data and numerical simulations. Our results show an in vivo murine iris stiffness of 96.1 ± 54.7 kPa (mean ± SD), which did not correlate with age but was dependent on gender. Our results further showed strong evidence of reverse pupillary block, with mean posterior chamber pressure remaining at approximately 12 mmHg even as anterior chamber pressure was set to much higher levels. Our approach to monitoring iris stiffness in vivo is applicable to study potential changes of iris stiffness in various pathophysiological conditions and thus has significant potential for clinical care of ocular disease involving iris biomechanics.

虹膜在某些类型的青光眼中起着重要作用，包括原发性闭角型青光眼和色素性青光眼。虹膜力学对于影响某些动物物种响应眼压变化的小梁网变形也很重要。尽管小鼠被广泛用于研究包括青光眼在内的眼部疾病，但小鼠虹膜的体内生物力学特性尚不清楚。因此，本研究的主要目的是估计小鼠虹膜生物力学硬度。我们使用连续增加 IOP 水平的活体小鼠（n = 13，年龄 = 7.3 ± 3.2 [平均值 ± SD] 个月）的前段光学相干断层扫描 (OCT) 图像，观察 IOP 依赖性虹膜变形。然后，我们使用逆有限元模型来预测相同条件下的虹膜变形，通过最大化 OCT 数据和数值模拟之间的一致性来估计虹膜刚度。我们的结果显示，体内小鼠虹膜硬度为 96.1 ± 54.7 kPa（平均值 ± 标准差），这与年龄无关，但取决于性别。我们的结果进一步显示了反向瞳孔阻滞的有力证据，即使前房压力设置为更高的水平，平均后房压力仍保持在大约 12 mmHg。我们监测体内虹膜硬度的方法适用于研究虹膜硬度在各种病理生理条件下的潜在变化，因此对于涉及虹膜生物力学的眼部疾病的临床护理具有巨大潜力。