There are no dramatic differences in predictability and efficacy between SMILE and LASIK at this time. SMILE has been less well-studied, and further large-scale studies are necessary to understand the safety profile better.
At this time, there have been several reported cases of corneal ectasia associated with SMILE. Corneal ectasia is a rare complication of laser eye surgeries. It results from abnormal weakening of the cornea and can lead to severe vision problems. Further study needs to be done to determine the actual risk of ectasia associated with SMILE.
There is an increased risk of decentered treatments with SMILE. Decentration of the treatment can cause symptoms such as blurred vision or ghosting after surgery. The advanced eye-tracking system on the LASIK excimer laser makes instances of decentered ablations extremely rare. Eye-tracking technology is not available with SMILE surgery. The surgeon cannot make further centration adjustments once the SMILE suction ring is applied to the eye.