The refractive procedure, small incision lenticule extraction (SMILE) may create a lower risk of post-op dry eye. A retrospective study evaluated incision size’s influence on dry eye symptoms in the SMILE procedure. Researchers split 47 patients with myopia and/or myopic astigmatism into three groups based on the incision applied during the surgery, 2-, 3- and 4mm.

When comparing Ocular Surface Disease Index scores, tear break-up time (TBUT), ST1 and staining grades, the study found no significant differences among the three groups in respect to pre-op and then from first day post-op up to six months post-op. The TBUT and ST1 values returned to pre-op levels in the first month, and OSDI scores and staining values returned to pre-op levels in the third month for all groups in the study. There were also no significant differences in symptoms in respect to age and sex.

Researchers noted that incision size differed during the learning period of SMILE procedures. Once the surgeon gained experience, that person made narrower incision sites.