Effect of 0.1% dexamethasone on epithelial healing in experimental corneal alkali wounds: morphological changes during the repair process.
BACKGROUND
The effect of 0.1% dexamethasone on epithelial healing was evaluated in corneal alkali wounds.


METHODS
Epithelial wounds were induced by a 60-s application of a round filter paper (5.5 mm) soaked in 1 N NaOH onto the central cornea of the rabbit. Animals were treated with 0.1% dexamethasone 4 times each day for 8 weeks in one subgroup and only for the 1st week in the other subgroup. The control eyes were treated with a balanced salt solution. The repair processes of epithelium and its basement membrane were evaluated morphologically and morphometrically.


RESULTS
Treatment with 0.1% dexamethasone was found to retard the repair process of epithelial healing compared with the control eyes. Morphologically, the basement membrane in the control cornea was damaged focally at 2 days, maximally disrupted at 4 weeks, and regained the normal integrity at 8 weeks after the initial alkali damage. In 0.1% dexamethasone-treated corneas, regardless of the application period, the basement membrane structure was visible up to 4 weeks but disappeared at 8 weeks after the initial alkali wounds. The eyes treated with 0.1% dexamethasone for 8 weeks showed an intense infiltration of inflammatory cells in the superficial stroma 4 weeks after treatment.


CONCLUSIONS
A topical application of 0.1% dexamethasone retarded the corneal epithelial healing. The cornea treated with 0.1% dexamethasone only for the 1st week maintained a well-preserved basement membrane for as long as 4 weeks after initial damage without enhancement of the inflammatory cell infiltration. However, further study is needed to prevent late disintegration of the basement membrane.
Chung
J H
JH
Department of Ophthalmology, Mokdong Hospital, Medical Research Center, College of Medicine, Ewha Women's University, Seoul, Korea.
Kang
Y G
YG
Kim
H J
HJ
D000818:Animals; D002057:Burns, Chemical / Q000188:drug therapy / Q000473:pathology*; D003907:Dexamethasone / Q000008:administration & dosage*; D019573:Epithelium, Corneal / Q000187:drug effects / Q000648:ultrastructure*; D005126:Eye Burns / Q000139:chemically induced* / Q000188:drug therapy / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000008:administration & dosage*; D009883:Ophthalmic Solutions; D011817:Rabbits; D012008:Recurrence; D012972:Sodium Hydroxide; D016896:Treatment Outcome; D014945:Wound Healing / Q000187:drug effects*
D005938:Glucocorticoids; D009883:Ophthalmic Solutions; D012972:Sodium Hydroxide; D003907:Dexamethasone