Role of the corneal epithelium in refractive changes following laser in situ keratomileusis for high myopia

J Refract Surg. 2000 Mar-Apr;16(2):133-9. doi: 10.3928/1081-597X-20000301-05.


Purpose: Epithelial hyperplasia is one of the factors that plays a role in myopic regression after photorefractive keratectomy (PRK). We evaluated the role of the epithelium following excimer laser in situ keratomileusis (LASIK) performed on highly myopic eyes.

Methods: Fifty eyes of 32 patients (18 females and 14 males; mean age, 31.7+/-6.5 years) were treated with LASIK for myopia with an attempted correction ranging between -8.50 and -12.25 D (mean, -10.48+/-1.43 D). No sutures were placed. The thickness of the central epithelium was evaluated either with a 50-MHz ultrasonic pachymeter or an ultrasound biomicroscope. Postoperatively, topical corticosteroid drops were administered for at least 1 month.

Results: Follow-up was at least 12 months. Epithelium measurements were thicker compared to preoperative measurements from the first week postoperatively (mean, +1.9 microm, +2.77%; P<.05). Epithelial thickness peaked at the third month after LASIK (mean, +6.5 microm, +9.5%; P<.05) and remained stable through 12 months. A negative correlation between epithelium thickness and manifest refraction from the first month postoperatively to the end of follow-up was present.

Conclusion: The epithelium seemed to have a role in the regression of refractive effect after LASIK to correct high myopia.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Corneal Topography
  • Epithelium, Corneal / pathology*
  • Female
  • Humans
  • Hyperplasia
  • Keratomileusis, Laser In Situ*
  • Male
  • Middle Aged
  • Myopia / pathology
  • Myopia / surgery*
  • Postoperative Period
  • Refraction, Ocular
  • Treatment Outcome