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.
Department of Ophthalmology, Mokdong Hospital, Medical Research Center, College of Medicine, Ewha Women's University, Seoul, Korea.
J H
JH
Chung
Y G
YG
Kang
H J
HJ
Kim
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