Based on a literature review of all reported cases of ectasia, the incidence of post-refractive ectasia in eyes without identifiable preoperative risk factors is 20 per 100,00 eyes for PRK, 90 per 100,000 eyes for LASIK, and 11 per 100,000 eyes for SMILE

Ectasia was found to be 4.5 times more likely after LASIK than PRK

Although SMILE appears to have the lowest rate of ectasia, its incidence may increase as more procedures are performed and cases are reported

The prevalence of keratoconus in the general population may contribute to postoperative ectasia, as patients seeking refractive surgery could have subclinical disease

The present study poses the question whether iatrogenic post-refractive ectasia may be a progression of pre-existing keratoconus