Corneal healing after uncomplicated LASIK and its relationship to refractive changes: a six-month prospective confocal study.
OBJECTIVE
To investigate corneal healing and the factor(s) possibly responsible for refractive changes after laser in situ keratomileusis (LASIK).


METHODS
Twenty eyes of 10 patients who underwent LASIK for myopia were examined clinically and by real-time confocal microscopy for 6 months. Epithelial and posterior stromal thicknesses and the thickness of the keratocyte activation zone were measured, and refractive changes were compared with these values. Keratocyte morphology, flap thickness, and subbasal nerve fiber bundle morphology after LASIK were also investigated.


RESULTS
No significant change was detected over time in epithelial thickness after LASIK treatment; however, the posterior stromal thickness was found to be significantly higher 1 month after surgery. A slight but statistically significant negative correlation was detected between the thickness of the keratocyte activation zone and the spheroequivalent refraction after LASIK. The subbasal nerve fiber bundle's morphology returned to its preoperative appearance 6 months after LASIK, but in the flap stroma the nerve fiber bundle morphology remained abnormal at 6 months after LASIK surgery.


CONCLUSIONS
A weak but significant negative correlation between the thickness of the keratocyte activation zone and spheroequivalent refraction was found after LASIK. The different refractive properties of activated keratocytes may be responsible for the myopic shift after LASIK. Further studies are needed to clarify this hypothesis.
Avunduk
Avni Murat
AM
Department of Ophthalmology, LSU Eye Center, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA. avunduk@ttnet.net.tr
Senft
Carl Joseph
CJ
Emerah
Sherif
S
Varnell
Emily D
ED
Kaufman
Herbert E
HE
D000328:Adult; D001837:Body Weights and Measures; D015331:Cohort Studies; D003319:Corneal Stroma / Q000294:innervation / Q000473:pathology*; D019573:Epithelium, Corneal / Q000473:pathology; D005260:Female; D005347:Fibroblasts / Q000473:pathology; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D018613:Microscopy, Confocal; D009216:Myopia / Q000601:surgery*; D009412:Nerve Fibers / Q000473:pathology; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology*; D013524:Surgical Flaps / Q000473:pathology*; D014945:Wound Healing