Confocal microscopy of corneal stroma and endothelium after LASIK and PRK.
OBJECTIVE
To compare with confocal microscopy the changes in stromal keratocyte density and endothelial cell count due to photorefractive keratectomy (PRK) and LASIK.


METHODS
In this prospective study, 32 eyes (16 myopic patients) were examined with the NIDEK Confoscan 3 confocal microscope before and 6 months after PRK and LASIK. The preoperative mean myopia was -2.85+/-0.99 diopters (D) (range: -1.00 to -4.00 D) in 24 eyes that underwent PRK and -2.94+/-0.96 D (range: -2.00 to -4.25 D) in 8 eyes that underwent LASIK. Keratocyte density in the anterior and posterior stroma and the endothelial cell count were measured. Statistically significant changes were assessed using the t test. P<.05 was considered statistically significant.


RESULTS
Preoperative hexagonal cell percentage in the LASIK group was 52.17+/-11.43 and 51.33+/-10.98 in the PRK group. Postoperatively, the percentages were 52.96+/-7.55 and 53.34+/-10.2, respectively. Six months postoperatively, keratocyte density changed by 367.12+/-103.35 cells/mm(2) (34.7% reduction) in the anterior stroma (P<.05) and 9.25+/-28.28 cells/mm(2) (1.31% reduction) in the posterior stroma (P>.05) for the LASIK group. In the PRK group, these values were 319.71+/-83.45 cells/mm(2) (31.13% reduction) in the anterior stroma (P<.05) and 0.17+/-38.97 cells/mm(2) (0.02% reduction) in the posterior stroma (P>.05). The changes in keratocyte densities were not statistically significant between groups (P>.05). The mean number of keratocytes decreased by 37.2% in the retroablation zone of the LASIK group (P<.05). No changes were noted in endothelial cell counts.


CONCLUSIONS
A significant decrease occurred in the number of stromal keratocytes in the anterior stroma. Despite differences in surgery, the change in keratocyte density and endothelial cell counts were similar between LASIK and PRK groups (P>.05).
Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Javad
J
Amoozadeh
Soheil
S
Aliakbari
Amir-Houshang
AH
Behesht-Nejad
Mohammad-Amin
MA
Seyedian
Bijan
B
Rezvan
Hassan
H
Hashemi
D000328:Adult; D001251:Astigmatism / Q000601:surgery; D002452:Cell Count; D003319:Corneal Stroma / Q000473:pathology*; D004728:Endothelium, Corneal / Q000473:pathology*; D005260:Female; D005347:Fibroblasts / Q000473:pathology; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D018613:Microscopy, Confocal; D009216:Myopia / Q000601:surgery; D018903:Photorefractive Keratectomy / Q000379:methods*; D011446:Prospective Studies; D055815:Young Adult