Effect of topical tranilast and corticosteroids on subepithelial haze after photorefractive keratectomy in rabbits.
BACKGROUND
Tranilast (trade name Rizaben), an anti-allergic drug with anti-inflammatory effects, is thought to inhibit synthesis of extracellular matrix of fibroblasts through the suppression of TGF-beta. We evaluated the effect of topical tranilast on the subepithelial haze that developed after excimer laser keratectomy and its effect was compared with that of betamethasone eye drops


METHODS
Excimer laser keratectomy (phototherapeutic keratectomy mode) was performed with the Nidek EC-5000 excimer laser on 16 rabbit corneas (eight rabbits). From the second postoperative day, topical 2% tranilast was instilled in the right eye and the control solution in the left eye, four times daily. Until the fourth week after the operation, we measured the densitometric values of scattered light intensity of the subepithelial haze with an anterior ocular analyzer, EAS-1000 (Nidek). At the fifth postoperative week, light and electron microscopy and immunohistochemistry with an antibody to TGF-beta were also performed.


RESULTS
Densitometric values of the subepithelial haze in the corneas treated with 2% tranilast were slightly less than those of the subepithelial haze in the control corneas. However, the values of the subepithelial haze in the betamethasone-treated corneas were significantly less than those in control corneas. Histochemical examinations revealed that topical tranilast had a small effect on the subepithelial haze after excimer laser keratectomy in rabbits.


CONCLUSIONS
Topical 0.1% betamethasone can limit the amount of subepithelial haze and tranilast may inhibit development of subepithelial haze by the suppression of TGF-beta.
Furukawa
H
H
Kanai Juntendo University, Department of Ophthalmology, Tokyo, Japan.
Nakayasu
K
K
Gotoh
T
T
Watanabe
Y
Y
Takano
T
T
Ishikawa
T
T
Kanai
A
A
D000287:Administration, Topical; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000494:pharmacology*; D001623:Betamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D003315:Cornea / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D003318:Corneal Opacity / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control* / Q000601:surgery; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D007150:Immunohistochemistry; D054018:Lasers, Excimer; D009883:Ophthalmic Solutions; D018903:Photorefractive Keratectomy / Q000009:adverse effects*; D011817:Rabbits; D016212:Transforming Growth Factor beta / Q000378:metabolism; D062367:ortho-Aminobenzoates / Q000008:administration & dosage / Q000494:pharmacology*
D000893:Anti-Inflammatory Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D009883:Ophthalmic Solutions; D016212:Transforming Growth Factor beta; D062367:ortho-Aminobenzoates; D001623:Betamethasone; C012293:tranilast