The Differential Expression of Cytokines and Growth Factors After SMILE Compared With FS-LASIK in Rabbits

Invest Ophthalmol Vis Sci. 2020 May 11;61(5):55. doi: 10.1167/iovs.61.5.55.


Purpose: To investigate the differential expression of cytokines and growth factors in the cornea and aqueous humor after small incision lenticule extraction (SMILE) compared with femtosecond LASIK (FS-LASIK) using rabbit model.

Methods: Sixteen eyes of 16 rabbits in each group underwent SMILE or FS-LASIK with refractive correction of -6.00 DS/-1.00 DC. Eight additional rabbits served as controls. Pre- and 24 hours, 1 week, 1 month, and 3 months postoperatively, slit-lamp and anterior segment optical coherence tomography were performed, followed by cornea and aqueous humor collection. Apoptosis and proliferation were evaluated with TUNEL assay and Ki-67 immunostaining, respectively. The mRNA and protein expression of cytokines and growth factors was determined by RT-qPCR and Western blotting, respectively. Cytokine levels in the aqueous humor were detected with ELISA.

Results: Compared with FS-LASIK, SMILE induced less apoptosis and proliferation in the cornea within 1 week postoperatively. Levels of IL-1β, TNF-α, and EGFR in the cornea were significantly increased after FS-LASIK compared with SMILE within 24 hours. Levels of IL-8 in the aqueous humor remained elevated until 1 week after FS-LASIK but not SMILE. TGF-β1 level was elevated up to 1 month after both procedures, while BFGF level was kept high within 1 month after SMILE but not FS-LASIK.

Conclusions: SMILE could induce significantly less acute inflammation than FS-LASIK in the cornea and aqueous humor. The differential expression of TGF-β1 and BFGF between two procedures until 1 month might contribute to the post-SMILE delayed recovery and underline the importance of continued treatment postoperatively.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aqueous Humor / metabolism*
  • Cornea / metabolism*
  • Cornea / surgery*
  • Cytokines / biosynthesis*
  • Female
  • Intercellular Signaling Peptides and Proteins / biosynthesis*
  • Keratomileusis, Laser In Situ*
  • Postoperative Period
  • Rabbits
  • Refractive Surgical Procedures* / methods
  • Time Factors


  • Cytokines
  • Intercellular Signaling Peptides and Proteins