Evaluation of corneal biomechanics in patients with keratectasia following LASIK using dynamic Scheimpflug analyzer

Jpn J Ophthalmol. 2018 Jul;62(4):443-450. doi: 10.1007/s10384-018-0594-5. Epub 2018 Apr 26.


Purpose: To investigate the corneal biomechanics in eyes with keratectasia following LASIK using a dynamic Scheimpflug analyzer.

Design: Case-Control study.

Method: The subjects in the study included 12 eyes with keratectasia after LASIK (KE), 24 eyes with keratoconus (KC), 17 eyes without keratectasia after LASIK (LASIK), and 34 eyes with normal corneas (Normal). Corneal biomechanics of the four groups were evaluated using a dynamic Scheimpflug analyzer.

Results: Compared with Normal (7.06 ± 0.54), the radius at the highest concavity (radius, mm) of LASIK (5.96 ± 0.76), KE (4.93 ± 0.61) and KC (5.39 ± 1.02) were significantly small. The Deflection Amplitude (HCDLA, mm) of Normal (0.94 ± 0.07) was significantly lower than those of KE (1.11 ± 0.10) and KC (1.06 ± 0.16), and was not significantly different from that of LASIK (0.98 ± 0.07). There were significant differences between LASIK and KE in radius and HCDLA (P < 0.05), whereas KE and KC had no differences in these parameters.

Conclusions: Corneal biomechanical features evaluated using the dynamic Scheimpflug analyzer suggest that biomechanical properties in eyes with keratectasia, keratoconus, and LASIK are different from those of normal eyes. Although the biomechanics in eyes with keratectasia differs from that in eyes with LASIK, it is similar to that in eyes with keratoconus.

Keywords: Biomechanics; Dynamic Scheimpflug analyzer; Keratectasia; Keratoconus; LASIK.

MeSH terms

  • Adult
  • Biomechanical Phenomena
  • Cornea / pathology
  • Cornea / physiopathology*
  • Corneal Diseases / diagnosis
  • Corneal Diseases / etiology
  • Corneal Diseases / physiopathology*
  • Corneal Topography / instrumentation*
  • Dilatation, Pathologic
  • Female
  • Humans
  • Keratoconus / surgery
  • Keratomileusis, Laser In Situ / adverse effects*
  • Male
  • Postoperative Complications / diagnosis
  • Postoperative Complications / etiology
  • Postoperative Complications / physiopathology*
  • Retrospective Studies