Effect of Shear Stress on Attachment of Corneal Endothelial Cells in Association With Corneal Endothelial Cell Loss After Laser Iridotomy

Abstract

The resistance of corneal endothelial cell loss to shear stress is time dependent. Shear stress could be a cause of corneal endothelial cell loss in some conditions of laser iridotomy.

Stereo-PIV study of flow inside an eye under cataract surgery

“…Kaji et al (2005) found there was an increased detachment of the corneal endothelial cells when the shear stress was above 0.1 Pa, which is comparable to the maximum shear stress (0.45 Pa) we observed in the present study. In addition, shear stress has also been shown to affect other endothelial cells such as vascular endothelial cells (Thoumine et al 1995) and hybridomas (Born et al 1992).…”

“…The viscous shear stress on the corneal endothelium was computed based on the measured mean velocity distribution. The magnitude of shear stress for micro coaxial cases with direct impingement of the irrigation flow on the cornea reached 0.45 Pa, which is comparable to the value of shear stress that caused detachment of the corneal endothelial cells reported by Kaji et al (2005). By avoiding direct impingement of the irrigation flow, the shear stress was reduced considerably.…”

“…Even hydrodynamic forces acting on the endothelial cells without sonification or rubbing of the nuclear materials are deleterious to the endothelium (Binder et al 1976). The tangential component of the hydrodynamic forces, i.e., shear stress, affects the endothelial cells such as vascular endothelial cells (Thoumine et al 1995), hybridomas (Born et al 1992), and even cornea endothelial cells (Kaji et al 2005).…”

Visualization of irrigation fluid flow and calculation of its velocity distribution in the anterior chamber by particle image velocimetry

“…For example, high velocity of the irrigation flow in the anterior chamber induces shear stress on the corneal endothelial layer. Our previous study showed that shear stresses larger than 3.0 dynes/cm 2 significantly reduced the number of adherent corneal endothelial cells on the basement membrane [14]. In addition, the velocity of irrigation flow will be involved in the clearance of viscoelastic materials from the anterior chamber.…”

Combined micro and macro additive manufacturing of a swirling flow coaxial phacoemulsifier sleeve with internal micro-vanes

“…Despite its importance, several studies have shown that the impinging flow from the irrigation solution on the corneal endothelial cells in the inner eye can damage these cells during the procedure (Polack and Sugar 1976;Binder et al 1976;Miller et al 1996;Hayashi et al 1996;Topaz et al 2002;O'Brien et al 2004;Steinert and Schafer 2006). It is believed that these cells and others can be damaged by this impinging flow through shear stresses resulting from the tangential component of the hydrodynamic forces (Binder et al 1976;Born et al 1992;Thoumine et al 1995;Kaji et al 2005). The present study was intended to develop a strategy for reducing the velocity of this impinging flow during the procedure and to demonstrate the feasibility of designing and manufacturing a new medical device that incorporates this new strategy.…”