Feng Xu, Li Guo-Yang, Jiang Yuxuan, Shortt-Nguyen Owen, Yun Seok-Hyun
Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, MA 02114, USA; Currently with the Department of Bioengineering, University of Texas at Dallas, TX 75080, USA.
Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, MA 02114, USA; Currently with the Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, China.
Acta Biomater. 2025 Jun 1;199:252-261. doi: 10.1016/j.actbio.2025.05.009. Epub 2025 May 2.
Lens tension is essential for accommodative vision but remains difficult to measure with precision. Here, we present an optical coherence elastography (OCE) technique that quantifies both tension and elastic modulus in the lens capsule and underlying tissue. This method derives mechanical parameters from surface wave dispersion across a critical frequency range of 1-30 kHz. Using isolated lenses from six-month-old pigs, we measured intrinsic anterior capsular tensions of 0-20 kPa and posterior capsular tensions of 40-50 kPa, induced by intra-lenticular pressure at the cortical surface. The mean shear moduli of anterior and posterior capsules were 630 kPa and 400 kPa, respectively, nearly 100-fold greater than that of the cortical tissues, where tensions were below 1 kPa. Biaxial zonular stretching (∼4% strain) increased anterior capsular tension by 67 kPa, with a low uncertainty of only 2 kPa. This optical method holds significant promise for diagnosing and managing accommodative dysfunctions through lens mechanics assessment in clinical settings. STATEMENT OF SIGNIFICANCE: Optical coherence elastography (OCE) is a rapidly advancing imaging modality, but its applications have been limited to stiffness measurements. This work represents a significant innovation by extending OCE capabilities to include force and stress quantification, broadening its potential applications in biomedical and clinical contexts. The ability to measure in situ capsular tension in the eye lens is a major breakthrough, as capsular tension is essential for transferring zonular fiber forces to the lens tissue during accommodation-a process critical for vision. This study provides quantitative insights into the mechanical mechanisms of accommodation and holds strong promise as a clinical tool for assessing lens tissue mechanics, addressing a capability gap in current clinical practice.
晶状体张力对于调节视力至关重要，但仍难以精确测量。在此，我们提出一种光学相干弹性成像（OCE）技术，该技术可量化晶状体囊膜及其下方组织的张力和弹性模量。此方法通过在1 - 30 kHz的临界频率范围内的表面波频散来推导力学参数。使用六个月大猪的离体晶状体，我们测量了皮质表面晶状体内部压力引起的前囊膜固有张力为0 - 20 kPa，后囊膜张力为40 - 50 kPa。前囊膜和后囊膜的平均剪切模量分别为630 kPa和400 kPa，比皮质组织的平均剪切模量大近100倍，皮质组织的张力低于1 kPa。双轴小带拉伸（约4%应变）使前囊膜张力增加了67 kPa，不确定性低至仅2 kPa。这种光学方法通过在临床环境中评估晶状体力学，在诊断和管理调节功能障碍方面具有重大前景。重要性声明：光学相干弹性成像（OCE）是一种快速发展的成像方式，但其应用仅限于刚度测量。这项工作通过扩展OCE的能力以包括力和应力量化，代表了一项重大创新，拓宽了其在生物医学和临床领域的潜在应用。测量眼内晶状体原位囊膜张力的能力是一项重大突破，因为囊膜张力对于在调节过程中将小带纤维力传递到晶状体组织至关重要——调节是视觉的关键过程。本研究为调节的力学机制提供了定量见解，并作为评估晶状体组织力学的临床工具具有很大前景，填补了当前临床实践中的能力空白。
