Objective Monitoring of Corneal Backward Light Scattering After Femtosecond Laser-assisted LASIK

J Refract Surg. 2016 Jan;32(1):20-5. doi: 10.3928/1081597X-20151207-08.

Abstract

Purpose: To investigate the changes in corneal backward light scattering, as measured by a rotating Scheimpflug camera with automated corneal densitometry software, in eyes treated with femtosecond laser-assisted LASIK (FS-LASIK).

Methods: The cornea was examined preoperatively and postoperatively at 1 day, 1 week, and 1, 3, and 6 months in 23 patients who underwent myopic FS-LASIK. Local analysis of corneal backscatter was performed on four concentric radial zones across a 12-mm diameter (0 to 2, 2 to 6, 6 to 10, and 10 to 12 mm) and at a different corneal depth (anterior 120 µm, central and posterior 60 µm).

Results: A statistically significant increase in corneal backward light scattering (P < .0001) was detected within the central 10 mm of the anterior cornea. The increase in corneal densitometry was gradually reversed over 6 months. The difference compared to preoperative values was no longer statistically significant at 3 and 6 months after surgery in the central cornea, whereas it remained significant in the mid-peripheral annulus (ranging from 6 to 10 mm), where the flap edge was located.

Conclusions: FS-LASIK is followed by an increase in corneal backward light scattering during the early postoperative period that returns to baseline by 3 months. Whereas the increase in corneal densitometry at the flap edge location can be related to a scarring reaction, the explanation for such an increase in the central anterior cornea remains speculative.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Astigmatism / physiopathology
  • Astigmatism / surgery*
  • Cornea / physiopathology*
  • Densitometry
  • Female
  • Humans
  • Keratomileusis, Laser In Situ / methods*
  • Lasers, Excimer / therapeutic use*
  • Light
  • Male
  • Middle Aged
  • Myopia / physiopathology
  • Myopia / surgery*
  • Photography
  • Prospective Studies
  • Scattering, Radiation*
  • Visual Acuity / physiology
  • Young Adult