Long-term prospective assessment of subconjunctival triamcinolone acetonide in addition to topical therapy in the management of chronic superficial keratitis

Abstract

Chronic superficial keratitis (CSK) is a progressive inflammatory disease in adult dogs, associated with corneal vascular proliferation, edema and melanic pigment deposition. In the absence of a curative therapy, the current approach for the management of CSK aims to control disease progression and eventually decrease the severity of corneal lesions. Subconjunctival injections of corticosteroids may be effective in severe cases, where topical therapy alone is inadequate. The aim of this study was to comprehensively evaluate the effectiveness of subconjunctival triamcinolone acetonide (TA) injection in addition to topical steroid treatment for the long-term management of CSK, in dogs unresponsive to conventional topical steroids. Treatment efficacy was assessed in 11 dogs with bilateral CSK by periodic evaluation of the cornea in terms of vascularization, edema and pigmentation for up to 120 weeks. Clinically significant reductions in corneal pigmentation (P<0.0001), vascularization (P<0.0001) and edema scores (P<0.0001) were achieved during therapy. The greatest reduction was exhibited by corneal edema, closely followed by vascularization. Corneal pigmentation was less responsive and complete regression has not been achieved in any of the dogs. Severely affected corneas exhibited greater improvements in terms of pigmentation, whereas moderately affected corneas showed a slight decrease. Corneal edema and vascularization were adequately controlled, whereas corneal pigmentation exhibited a lower decrease in severity and was more difficult to manage on a long-term basis. This study suggests that subconjunctival injection of TA in addition to topical steroids could represent an effective option for long-term management of CSK in dogs unresponsive to topical steroids alone