Clinical study on the application of dexamethasone and cyclosporine/dimethyl sulfoxide combination eye drops in the initial therapy of chronic superficial keratitis in dogs

Abstract

Purpose: To assess the initial therapy of chronic superficial keratitis (CSK) in dogs with the use of dexamethasone and cyclosporine/ dimethyl sulfoxide combination eye drops.

Methods: The study was conducted on 41 dogs - 16 males and 25 females, aged 2 to 9 years, diagnosed with CSK. The disease was treated with two kinds of eye drops containing 0.1% dexamethasone and 0.75% cyclosporine in combination with 30% DMSO, administered three times a day. Prior to the treatment and after 5 weeks of therapy, depigmentation of the third eyelid margin, corneal neovascularization and pigmentation were assessed. The percentage of the corneal surface afflicted with inflammatory processes was calculated with the use of IsoCalc.com's Get Area software for CorelDRAW12.

Results: The administered therapy resulted in a significant decrease in the mean number of quadrants affected by corneal neovascularization in the right eye from 2.63 prior to treatment to 0.24 after treatment (p⟨0.001), and the left eye from 2.66 to 0.59 (p⟨0.001), respectively. Mean corneal surface afflicted with inflammatory processes was statistically significantly reduced from 53.5% to 26.3% (p⟨0.001) in the case of right corneas, and from 54.5% to 30.2% (p⟨0.001) in the case of left corneas. Of 77 corneas diagnosed with pigmentation, pigmentation reduction was observed in 54 and pigmentation increase in 27.

Conclusions: Using dexamethasone and cyclosporine/DMSO combination eye drops proved to be a viable initial therapy against CSK, which facilitates reduction of inflammatory processes and neovascularization atrophy, but in many cases does not inhibit the progress of pigmentation.

Keywords: DMSO; German Shepherd; chronic superficial keratitis; cyclosporine.