Mitomycin C alters corneal stromal wound healing and corneal haze in rabbits after argon-fluoride excimer laser photorefractive keratectomy.
OBJECTIVE
To investigate the effects of mitomycin C (MMC) on rabbit cornea wound healing after photorefractive keratectomy (PRK).


METHODS
Rabbit corneas were stained with dichlorotriazinyl aminofluorescein immediately after PRK. MMC was applied to the right eye and phosphate-buffered salt solution (PBS) to the left. Corneal epithelial wound healing rate and corneal haze were examined. Ultrasound pachymetry was performed. Stromal collagen regeneration was evaluated by fluorescent microscopy. We used terminal deoxyribonucleotidyl transferase-mediated D-uridine 5'-triphosphated-digoxigenin nick-end labeling (TUNEL) assay and transmission electron microscopy (TEM) to evaluate keratocyte apoptosis.


RESULTS
In eyes treated with MMC, there was no delay to the healing rate of corneal epithelial wound, and less haze 4 weeks after PRK. Ultrasound pachymetry showed thinner corneal thickness in MMC-treated eyes at week 4. Corneal stromal thickness regression was less in MMC-treated eyes observed by fluorescent microscope at week 4. Keratocyte apoptosis was noted in both MMC- and PBS-treated eyes by TUNEL assay and TEM observation. This study discovered the phenomenon that MMC prolongs keratocyte apoptosis.


CONCLUSIONS
Applying MMC after PRK is an effective method to decrease haze formation and corneal stromal thickness regression in rabbit corneas. The effect may be related to MMC prolonging keratocyte apoptosis.
Lai
Yu-Hung
YH
Department of Ophthalmology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung, Taiwan.
Wang
Hwei-Zu
HZ
Lin
Chang-Ping
CP
Chang
Shun-Jen
SJ
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001128:Argon; D003318:Corneal Opacity / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D003319:Corneal Stroma / Q000187:drug effects / Q000473:pathology / Q000601:surgery*; D005459:Fluorides; D007322:Instillation, Drug; D054018:Lasers, Excimer; D008297:Male; D016685:Mitomycin / Q000008:administration & dosage / Q000627:therapeutic use*; D018903:Photorefractive Keratectomy / Q000009:adverse effects*; D011817:Rabbits; D014945:Wound Healing / Q000187:drug effects*
D016685:Mitomycin; C047730:argon fluoride; D001128:Argon; D005459:Fluorides