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


CONCLUSIONS
The epithelium seemed to have a role in the regression of refractive effect after LASIK to correct high myopia.
Spadea
L
L
Department of Ophthalmology, University of L'Aquila, Italy. lspadea@ntt.it
Fasciani
R
R
Necozione
S
S
Balestrazzi
E
E
D000328:Adult; D019781:Corneal Topography; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D006801:Humans; D006965:Hyperplasia; D020731:Keratomileusis, Laser In Situ; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000473:pathology / Q000601:surgery*; D011184:Postoperative Period; D012029:Refraction, Ocular; D016896:Treatment Outcome