New instruments for lenticule extraction in small incision lenticule extraction (SMILE)

Small incision lenticule extraction (SMILE) is an alternative to Laser-Assisted in situ Keratomileusis (LASIK) for correction of myopia. In cases where surgeons inadvertently dissect the posterior surface first, identification of the anterior surface and subsequent removal become difficult since the anterior surface of the lenticule is compacted against the anterior stromal surface. This may result in incomplete lenticule removal, and a remnant of intrastromal lenticule in SMILE may lead to visual sequelae. In order to aid surgeons in lenticule removal, we have designed and developed 5 novel SMILE lenticule strippers to locate and extract the lenticules more easily. The aim of this study was to investigate and compare the efficacy and quality of these lenticule strippers in assisting SMILE. Thirty porcine eyes were used. The ease of extraction and removal of the lenticule with different strippers was graded by an experienced SMILE surgeon, the extracted lenticule circularity was evaluated by calculating the lenticule circularity, and the intactness of the extracted lenticule edge was assessed using scanning electron microscopy. We found these novel strippers can be of great help to improve the safety and quality of SMILE surgery, particularly in those cases of difficult lenticule extraction.