Nasolacrimal Stent with Shape Memory as an Advanced Alternative to Silicone Products

Abstract

Epiphora is the overflow of tears typically caused by obstruction or occlusion of the nasolacrimal duct. Implantation of a silicone stent is the preferred treatment for epiphora; however, introducing a silicone stent into a narrow duct with complex geometry is challenging as it requires guidance by a sharp metal wire. Additionally, silicone can cause adverse reactions such as biofilm formation and tear flow resistance due to its extreme hydrophobicity. To overcome these problems, in this study we developed a new type of biocompatible shape memory polymer (SMP) stent with elasticity capacity for self-expansion. We demonstrate both in vitro and in vivo that the SMP stent is more efficient in terms of tear drainage capacity and exhibits greater resistance to biofilm formation than a silicone control, suggesting that it is a superior alternative to currently used materials for nasolacrimal stents.