Comparative Analysis of Silk Fibroin Membranes across Cross-Linking Methods: Processing and Characterization.

Silk fibroin (SF) extracted from silkworm silk can be transformed into transparent membranes with well-suited physical properties for ophthalmic applications. There is ample literature on the fabrication and characterization of SF-based membranes; however, the use of diverse SF extraction protocols and characterization methods or their settings makes it difficult to compare different silk membrane properties across studies. In this work, we fabricated 10 families of SF-based membranes by physical cross-linking and one non-cross-linked as a control.

A simple computational model for scleral stiffness assessments via air-puff deformation OCT.

The mechanical properties of the sclera are related to its structural function, and changes to these properties are believed to contribute to pathologies such as myopia. Air-puff deformation imaging is a tool that uses an imaging system coupled with an air-puff excitation source to induce and measure deformation in a tissue . Typically used for the study of the cornea's mechanical properties and IOP, this tool has been proposed as a method to evaluate scleral stiffness.

Estimation of Crystalline Lens Material Properties From Patient Accommodation Data and Finite Element Models.

Purpose: The mechanical properties of the crystalline lens are related to its optical function of accommodation, and their changes with age are one of the potential causes for presbyopia. We estimated the mechanical parameters of the crystalline lens using quantitative optical coherence tomography (OCT) imaging and wavefront sensing data from accommodating participants and computer modeling.

Methods: Full-lens shape data (from quantitative swept-source OCT and eigenlens representation) and optical power data (from Hartmann-Shack wavefront sensor) were obtained from 11 participants (22-30 years old) for relaxed accommodation at infinity and -4.

Estimation of scleral mechanical properties from air-puff optical coherence tomography.

We introduce a method to estimate the biomechanical properties of the porcine sclera in intact eye globes , using optical coherence tomography that is coupled with an air-puff excitation source, and inverse optimization techniques based on finite element modeling. Air-puff induced tissue deformation was determined at seven different locations on the ocular globe, and the maximum apex deformation, the deformation velocity, and the arc-length during deformation were quantified. In the sclera, the experimental maximum deformation amplitude and the corresponding arc length were dependent on the location of air-puff excitation.

Material Properties from Air Puff Corneal Deformation by Numerical Simulations on Model Corneas.

Objective: To validate a new method for reconstructing corneal biomechanical properties from air puff corneal deformation images using hydrogel polymer model corneas and porcine corneas.

Methods: Air puff deformation imaging was performed on model eyes with artificial corneas made out of three different hydrogel materials with three different thicknesses and on porcine eyes, at constant intraocular pressure of 15 mmHg. The cornea air puff deformation was modeled using finite elements, and hyperelastic material parameters were determined through inverse modeling, minimizing the difference between the simulated and the measured central deformation amplitude and central-peripheral deformation ratio parameters.