Comparison of tear proteomic and neuromediator profiles changes between small incision lenticule extraction (SMILE) and femtosecond laser-assisted in-situ keratomileusis (LASIK)

Abstract

In this randomized controlled and paired-eye study, we investigated the tear proteomic and neuromediator profiles following small incision lenticule extraction (SMILE) versus laser-assisted in-situ keratomileusis (LASIK). Tear samples were analyzed using sequential window acquisition of all theoretical fragment ion mass spectrometry and DAVID Bioinformatics for enriched gene ontology terms. Tear neuromediators levels were correlated with clinical parameters. We found SMILE and LASIK shared some similar biological responses postoperatively, but there was significant up-regulation in leukocyte migration and wound healing at 1 week, humoral immune response and apoptosis at 1 month, negative regulation of endopeptidase activity at 3 to 6 months, and extracellular structure organization at 1 year in the post-LASIK eyes. Post-SMILE eyes had significantly better Oxford staining scores and tear break-up time (TBUT) than post-LASIK eyes at 1 and 3 months, respectively. Tear substance P and nerve growth factor levels were significantly higher in the LASIK group for 3 months and 1 year, respectively. Tear mucin-like protein 1 and substance P levels were significantly correlated with TBUT (r = -0.47, r = -0.49, respectively). This is the first study to demonstrate the detailed proteomic changes in SMILE and LASIK, providing new insights into the biological responses on the ocular surface after refractive surgery. © 2020