"Meniscus Sign" to Identify the Lenticule Edge in Small-Incision Lenticule Extraction.

PURPOSE: To describe our technique of lenticule edge identification in small-incision lenticule extraction using the "meniscus sign" to prevent lenticule misdissection.

METHODS: Femtosecond laser application for small-incision lenticule extraction was performed. A "double ring" was visible, signifying the edge of the cap cut (outer ring) and lenticule cut (inner ring). The anterior and posterior lamellar planes were delineated in 2 different directions. During creation of the posterior lamellar channel, the lenticule edge was slightly pushed away from the surgeon to create a gap between the inner ring (diameter of the lenticule cut) and the lenticule edge. The lenticule edge assumed a frilled wavy appearance, and the meniscus sign was observed as a gap between the lenticule edge and the inner ring. The meniscus-shaped gap served as a landmark to identify the lenticule edge, and the relationship between the frilled lenticule edge and surgical instruments further acted as a guide to identify the correct plane of dissection.

RESULTS: This technique was successfully undertaken in 50 eyes of 25 patients. The meniscus sign was observed in all cases, and no case had cap lenticular adhesions.

CONCLUSIONS: The meniscus sign helps to identify the lenticule edge and correct dissection planes and provides a visual landmark during the entire surgical procedure.