3D Finite Element Modeling of Femtosecond Laser Trabeculotomy.

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Computational Modeling

Background:

• Open-angle glaucoma is a leading cause of blindness.
• Femtosecond laser image guided high precision trabeculotomy (FLigHT) offers a novel, minimally invasive treatment approach.
• FLigHT aims to reduce intraocular pressure (IOP) by creating a drainage channel for aqueous humor (AH).

Purpose of the Study:

• To develop a 3D finite element model (FEM) of the FLigHT procedure.
• To simulate the clinical outcomes of FLigHT for varying drainage channel dimensions.
• To predict the optimal channel size for maximum IOP reduction.

Main Methods:

• Constructed a 3D FEM of the human eye, including anterior chamber (AC), trabecular meshwork (TM), Schlemm's canal (SC), and collector channels (CCs).
• Modeled TM and CCs as porous materials, estimating permeability through iterative simulations against clinical IOP data.
• Simulated FLigHT by creating an AC-to-SC channel, varying its cross-sectional area from 200μm x 500μm down to 50μm x 50μm.

Main Results:

• The minimum achievable IOP post-FLigHT is determined by SC pressure, CC permeability, AH inflow, and episcleral venous pressure, not TM permeability.
• A drainage channel size of 100μm x 100μm was predicted to be sufficient for maximal IOP reduction.
• Increasing channel size beyond 100μm x 100μm yielded no significant additional IOP decrease.

Conclusions:

• The developed 3D FEM accurately simulates IOP reduction following FLigHT.
• The model demonstrates predictive capability for drainage channel geometry and IOP outcomes.
• This computational model can assist in optimizing the clinical design and application of FLigHT procedures.