March 9, 2018 Conference
PURPOSE: To highlight the new technology and future trends in refractive surgery introduced by lenticular extraction (SMILE).
METHODS: Small incision lenticular extraction (SMILE) is a new generation form of laser vision correction that has been growing in popularity outside the U.S. over the past 9-10 years, and is now experiencing early U.S. adoption since its FDA approval 1 year ago. The technique involves a femtosecond laser created posterior lenticular shaped interface and anterior uniform thickness cap with a small external incision through which the refractive lenticule is extracted. The greater preservation of the ocular surface, anterior corneal fibers, and corneal nerves make it less invasive than LASIK. However, the steps of longer laser delivery, dissection and extraction make it more technically challenging than LASIK. With the laser assisted extraction of lenticules comes the possibility of lenticular implantation in the future.
RESULTS: SMILE has grown to greater than 1 million procedures world-wide this past year with over 500,000 Chinese procedures being performed in 2017 alone. In many OUS locations, SMILE has become the dominant refractive procedure being 80+% of cases in Shanghai and South Africa and 60% in Sydney, Australia. SMILE’s growth in the U.S. is more tempered, due to only spherical myopic approval, but astigmatism approval is forthcoming within the next year. SMILE is believe to be superior to LASIK in its avoidance of flap related complications, less potential dry eyes, less biomechanical instability, closed system precision and the momentum of a new procedure without the historical limitations of LASIK. The potential for intraoperative complications can be minimized by redocking in the case of suction loss, careful dissection of the anterior and then posterior interface, and inspection of the extracted lenticule to avoid partial removal. So far, the potential for lenticular implantation has been proposed for the correction of hyperopia, presbyopia and keratoconus.
CONCLUSION: SMILE has the potential to strongly co-exist and even replace LASIK as the dominant procedure in refractive surgery. With refractive eyebanking of extracted lenticules, a new era of tissue addition in refractive surgery could revolutionize the way we correct certain refractive errors.