Topical vitamin E and hydrocortisone acetate treatment after photorefractive keratectomy.
OBJECTIVE
To investigate the effects of topical vitamin E and hydrocortisone acetate treatments on corneal healing response after -10.0 D photorefractive keratectomy (PRK) in rabbits.


METHODS
Thirty-three New Zealand white rabbits were divided into four groups and -10 D PRK was performed under in vivo conditions. Following PRK, group 1 (n = 9) received no topical treatment and served as control. Group 2 (n = 8) received 0.1% hydrocortisone acetate ointment twice a day, group 3 (n = 8) received 1% vitamin E ointment and group 4 (n = 8) received both 0.1% hydrocortisone acetate and 1% vitamin E twice a day for a month. At the end of the third month, corneal haze was graded and the corneal hydroxyproline levels were measured, as a crude indicator of new collagen synthesis. Finally corneal samples were examined by transmission electron microscopy.


RESULTS
Non-homogeneously distributed strong haze was identified in group 1 which was greater than in the other groups; haze was least in groups 2 and 4. Corneal hydroxyproline levels were found to be significantly lower in groups 2, 3 and 4 compared with the control (Student's t-test, p < 0.05). Histopathologically, the most aggressive wound healing response was detected in group 1. The corneal wound healing response of group 2 was less than that of group 1 and equal to or more than that of group 4.


CONCLUSIONS
Deep corneal photoablation induces an aggressive healing response, and topical hydrocortisone acetate reduces this corneal wound healing effectively. The inhibitory effect of topical vitamin E on corneal wound healing seems to be less than that of hydrocortisone acetate, but combined treatment with these two drugs may have an additive effect in controlling corneal wound healing after PRK.
Bilgihan
K
K
Gazi University Medical Faculty, Department of Ophthalmology, Ankara, Turkey. bilgihan@behcet.tip.gazi.edu.tr
Ozdek
S
S
Ozoğul
C
C
Gurelik
G
G
Bilgihan
A
A
Hasanreisoğlu
B
B
D000287:Administration, Topical; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D003315:Cornea / Q000737:chemistry / Q000648:ultrastructure; D004359:Drug Therapy, Combination; D006854:Hydrocortisone / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006909:Hydroxyproline / Q000032:analysis; D054018:Lasers, Excimer; D008854:Microscopy, Electron; D018903:Photorefractive Keratectomy; D011817:Rabbits; D014810:Vitamin E / Q000627:therapeutic use*; D014945:Wound Healing / Q000187:drug effects*
D000893:Anti-Inflammatory Agents; D014810:Vitamin E; C021650:hydrocortisone acetate; D006909:Hydroxyproline; D006854:Hydrocortisone