PhD Defense: Vahoura Tahsini Maps and Characterizes Ocular Tissues

In this work, Vahoura focused on the characterization of the crystalline lens, cornea, and sclera to better understand their material properties with the goal of improvement of the clinical decision and treatment of occular conditions. To achieve this, she evaluated the mechanical properties of the porcine crystalline lens, cornea, and sclera using Optical Coherence Elastography (OCE). She further employed a novel analysis technique, the Strain-Stress Index (SSI), to characterize the age-related regional mechanical properties of the human cornea in vivo.

Her main findings demonstrate the strength of OCE for detailed biomechanical analysis of ocular tissues, both in vivo and ex vivo - revealing key differences in crystalline lens stiffness and viscoelasticity, as well as stress-dependent and auxetic behavior in the cornea. She combined OCE with uniaxial tensile testing, which enabled the assessment of the tissues' three-dimensional mechanical properties. Integrating SSI further allowed her to make the first in-vivo mapping of regional and age-related corneal stiffness, offering valuable insights for diagnostics and surgical planning.

Congratulations to Dr. Vahoura Tahsini on this incredible achievement and contributing to a better understanding of ocular biomechanics through her comprehensive characterization of ocular tissues!

Publications:

Tahsini, Vahoura; Redaelli, Elena; Frigelli, Matteo; Calvo, Begoña; Grasa, Jorge; Büchler, Philippe; Kling, Sabine (2025). Simultaneous axial and transverse mechanical characterization of the cornea and sclera: Insights from optical coherence elastography. Under internal revision.

Tahsini, Vahoura; Jiménez-García, Marta; Makarem, Ahmed; Elsheikh, Ahmed; Büchler, Philippe; Kling, Sabine; Rozema, Jos J. (2025). Regional corneal biomechanics assessment as a function of age using Strain-Stress Index maps. Ophthalmic and Physiological Optics.

Kling, Sabine; Tahsini, Vahoura; Hafezi, Farhad (2025). Dynamic in vivo mapping of the gradient refractive index and strain distribution of the human lens under accommodative stress. Experimental Eye Research 255. Elsevier 10.1016/j.exer.2025.110332

Kling, Sabine; Frigelli, Matteo; Aydemir, Enes; Tahsini, Vahoura; Torress-Netto, Emilio A.; Kollros, Leonard; Hafezi, Farhad (2024). Unveiling the Inner Mechanism of the Human Lens: Optical Coherence Tomography Measures Gradient Refractive Index and Mechanical Stiffness Gradient with High Resolution. Communications Medicine 4(162). Springer Nature 10.1038/s43856-024-00578-9

Tahsini, Vahoura; Gil, Iulen Cabeza; Kling, Sabine (2024). Storage-induced mechanical changes of porcine lenses assessed with optical coherence elastography and inverse finite element modeling. Frontiers in Bioengineering and Biotechnology 12. Frontiers Media 10.3389/fbioe.2024.1398659

Gil, Iulen Cabeza; Tahsini, Vahoura; Kling, Sabine (2023). Viscoelastic properties of porcine lenses using optical coherence elastography and inverse finite element analysis. Experimental Eye Research 233. Elsevier 10.1016/j.exer.2023.109558