Simulation of fluid-structure interaction during the phaco-emulsification stage of cataract surgery

During cataract surgery the clouded lens is broken up by phacoemulsification. The iris can become highly mobile and could be entrained phacoemulsification probe, under a condition known as intraoperative floppy syndrome (IFIS). In this study we explore mechanism of IFIS during phacoemulsification-based using fluid-structure interaction (FSI) simulations. As first its kind, developed simplified two-dimensional simulation framework utilized it to elucidate dynamics surrounding aqueous humor phaco-emulsification. Three types were observed when phaco probe was operated in torsional vibration mode placed at various locations anterior chamber, which termed repulsion (where repelled probe), attraction drawn toward probe) adhesion adhered some point along length), respectively. chamber partitioned into different zones exhibit each these three modes. Furthermore, effects stiffness length well power frequency operation investigated. It found that mitigated increasing stiffness, shortening (i.e., pupil dilation), decreasing emulsification maintaining range around iris’ fundamental bending mode. This provides new physical insights fluid-iris phaco-emulsification, may guide clinicians optimize their surgical protocol.