Numerical investigation of laser iridotomy influence on shear stress exerted on corneal endothelial cells / 医用生物力学

ABSTRACT

Objective To study the influence of laser peripheral iridotomy (LPI) on aqueous humor flow in eyes of patients and fluid shear stress exerted on the corneal endothelial cells. Methods A complete three-dimensional geometric eye model was established by CAD software with references to human eye geometric data from the literature. Numerical simulations on the flow conditions of aqueous humor and the shear stress exerted on corneal endothelial cells after LPI surgery were performed using finite element software. The simulation results of shear stresses at different positions of the laser hole in the iris before and after LPI surgery were compared. Results If the laser hole punched more closer to the pupil axis in iris, the shear stress exerted on corneal inner surface would be smaller. The maximum shear stress exerted on corneal endothelium was 16.5, 25.8, 57.0, 179.8 mPa when the distance between laser hole and the pupil axis was 4.0, 4.5, 5.0, 5.5 mm, respectively. With laser hole at 3 and 6 o’clock orientation, the maximum shear stress exerted on corneal inner surface was 13.7% and 4.2% greater than that at 12 o’clock position (56.95 mPa). ConclusionsLPI can influence the intraocular aqueous humor flow and shear stress exerted on corneal endothelial cells. The suitable position can decrease the shear stress exerted on corneal endothelial cells and reduce the risk of postoperative bullous keratopathy for patients after LPI surgery.