EFFECT OF TOPICAL TRANILAST AND CORTICOSTEROIDS ON SUBEPITHELIAL HAZEAFTER PHOTOREFRACTIVE KERATECTOMY IN RABBITS

BACKGROUND: Tranilast (trade name Rizaben), an anti-allergic drug with anti-inflammatory effects, is thought to inhibit synthesis of extrace llular matrix of fibroblasts through the suppression of TGF-beta. We e valuated the effect of topical tranilast on the subepithelial haze tha t developed after excimer laser keratectomy and its effect was compare d with that of betamethasone eye drops METHODS: Excimer laser keratect omy (phototherapeutic keratectomy mode) was performed with the Nidek E C-5000 excimer laser on 16 rabbit corneas (eight rabbits). From the se cond postoperative day, topical 2% tranilast was instilled in the righ t eye and the control solution in the left eye, four times daily. Unti l the fourth week after the operation, we measured the densitometric v alues of scattered light intensity of the subepithelial haze with an a nterior ocular analyzer, EAS-1000 (Nidek). At the fifth postoperative week, light and electron microscopy and immunohistochemistry with an a ntibody to TGF-P 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 corn eas, However, the values of the subepithelial haze in the betamethason e-treated corneas were significantly less than those in control cornea s. Histochemical examinations revealed that topical tranilast had a sm all effect on the subepithelial haze after excimer laser keratectomy i n rabbits. CONCLUSION: Topical 0.1% betamethasone can limit the amount of subepithelial haze and tranilast may inhibit development of subepi thelial haze by the suppression of TGF-beta.