An elongate electrode is configured to flex and generate plasma to incise tissue. An electrical energy source operatively coupled to the electrode is configured to provide electrical energy to the electrode to generate the plasma. A tensioning element is operatively coupled to the elongate electrode. The tensioning element can be configured to provide tension to the elongate electrode to allow the elongate electrode to flex in response to the elongate electrode engaging the tissue and generating the plasma. The tensioning element operatively coupled to the flexible elongate electrode may allow for the use of a small diameter electrode, such as a 5 μm to 20 μm diameter electrode, which can allow narrow incisions to be formed with decreased tissue damage. In some embodiments, the tensioning of the electrode allows the electrode to more accurately incise tissue by decreasing variations in the position of the electrode along the incision path.