A combined experimental-computational approach for retinal characterization

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Materials Science

Background:

• Subretinal injections for inherited retinal diseases risk tissue damage from mechanical stress.
• Existing methods like uniaxial tensile testing have limitations for characterizing retinal mechanical properties.
• A standardized protocol is needed to understand retinal biomechanics for safer surgical interventions.

Purpose of the Study:

• To introduce a combined experimental-computational approach using small punch testing and finite element simulations.
• To investigate the retina's elastic behavior under biaxial deformations.
• To establish a reproducible method for measuring retinal mechanical properties.

Main Methods:

• Evaluated environmental impacts (air, saline, temperature) on retinal elasticity via uniaxial tensile tests.
• Developed and validated a small punch test protocol for measuring load-displacement response under biaxial stress.
• Utilized finite element simulations to analyze retinal deformations and determine elastic modulus.

Main Results:

• Environmental conditions did not significantly alter retinal elastic modulus.
• Successfully established a reproducible small punch test for biaxial deformation analysis.
• Determined the retina's elastic modulus to be 5.5 kPa using the combined approach.

Conclusions:

• The combined small punch test and finite element simulation approach is a viable alternative to uniaxial testing for retinal biomechanics.
• Accurate characterization of retinal mechanical properties is essential for minimizing complications during gene therapy injections.
• This methodology can inform predictive in silico models and the development of biomimetic scaffolds for retinal repair.