Changes in Corneal Epithelial Thickness in Different Areas After Femtosecond Laser-Assisted LASIK in Patients With High Astigmatism

J Refract Surg. 2024 Apr;40(4):e239-e244. doi: 10.3928/1081597X-20240311-04. Epub 2024 Apr 1.


Purpose: To explore changes in corneal epithelial thickness (CET) after femtosecond laser-assisted laser in situ keratomileusis in patients with high astigmatism.

Methods: CET was measured at every intersection of the concentric circles and specific axes using AngioVue optical coherence tomography (Angio-OCT) preoperatively and 1 month postoperatively. The average thickness of corneal central, paracentral, and peripheral regions was the mean of the points within the central 2, 2 to 5, and 5 to 7 mm areas, respectively. Correlation analysis was performed to investigate the association between CET along different axes and other preoperative and postoperative parameters.

Results: Forty-two eyes of 28 patients were included. CET along the astigmatic (K1) and perpendicular (K2) axes in the central and paracentral areas increased (P < .001), whereas that along the K2 axis decreased in the peripheral area 1 month postoperatively (P = .001). The amount of CET change in the peripheral area between the K1 and K2 axes was significantly different (P < .001). In the central area, the change in CET along the K2 axis was positively correlated with ablation depth (r = 0.315, P = .042) and negatively with refractive power after surgery (r = -0.347, P = .024). In the peripheral area, the changes in CET along both K1 and K2 axes were negatively correlated with ablation depth (r = -0.431, P = .004; r = -0.387, P = .011, respectively).

Conclusions: Epithelial modeling differed between the different astigmatism axes after refractive surgery. The compensatory response of the corneal epithelium is more pronounced along the steeper axis. [J Refract Surg. 2024;40(4):e239-e244.].

MeSH terms

  • Astigmatism* / surgery
  • Humans
  • Keratomileusis, Laser In Situ* / methods
  • Lasers
  • Lasers, Excimer / therapeutic use
  • Myopia* / surgery
  • Prospective Studies
  • Visual Acuity