Authors:Krzysztof Radziejewski and Ireneusz Balicki
The aim of this study was to evaluate the efficacy of tacrolimus eye drops in alleviating the clinical symptoms of canine keratoconjunctivitis sicca (KCS) and to compare this efficacy with that of cyclosporine. The clinical study was conducted on 40 dogs diagnosed with idiopathic KCS. The dogs were divided into two groups of 20 animals each. In Group I, 0.75% cyclosporine eye drops were administered three times a day, while in Group II 0.02% tacrolimus eye drops were given twice daily. In addition, each group was subdivided into three subgroups based on the results of Schirmer tear test I (STT I). Clinical and ophthalmologic examinations were performed prior to the treatment as well as after one and two months of therapy. The application of both tacrolimus and cyclosporine resulted in a significant reduction of neovascularisation after the first and second month of treatment (P < 0.05, P < 0.001); however, in moderate and advanced stages, the observed efficacy of tacrolimus was higher. Across all patients, a significant increase in STT I values was observed after both the first and second month of treatment with tacrolimus (P < 0.01), as well as after two months of treatment with cyclosporine (P < 0.05). In both groups, some patients were observed to exhibit inhibited development of pigmentation, but an analysis of particular clinical cases and statistical data revealed no statistically significant discrepancies in the course of the study. In cases of advanced canine KCS, the efficacy of tacrolimus may be higher than that of cyclosporine.
Authors:Ireneusz Balicki and Aleksandra Sobczyńska-Rak
The objective of this study was to measure the vascular endothelial growth factor (VEGF) levels in dogs diagnosed with chronic superficial keratitis (CSK). The study was performed on 25 German shepherds (14 males and 11 females, aged between 3 and 11 years). The VEGF levels were determined in blood serum using commercially available enzyme-linked immunosorbent assay (ELISA; Quantikine Canine VEGF Immunoassay, R&D Systems). The test group of affected German shepherds was subdivided into two subgroups, based on the area of corneal neovascularisation. The first subgroup (9 patients) comprised dogs with neovascularisation observed in 1 to 2 quadrants of the right and left cornea, while the second subgroup (16 patients) comprised dogs with neovascularisation observed in 3 to 4 quadrants of the right and left cornea. The control group comprised 12 clinically healthy German shepherds (7 males and 5 females, aged between 3 and 9 years). The results were then statistically analysed by the Mann-Whitney test. The study indicated that the median serum VEGF concentration in healthy dogs was 14.9 pg/mL. The VEGF level observed in sick German shepherds was elevated (19.5 pg/mL) as compared to the values found in healthy dogs; however, a statistically significant increase in VEGF concentration, as compared to the values observed in healthy dogs, was only noted in the first subgroup, where the median VEGF concentration was 22.0 pg/mL. Elevated serum VEGF concentration was observed in German shepherds diagnosed with CSK. A statistically significant increase in VEGF levels was observed in dogs in the first stage of the disease, i.e. the early stage of neovascularisation.
Authors:Krzysztof Radziejewski, Ireneusz Balicki and Mateusz Szadkowski
The purpose of this study was to assess the condition of cells in the conjunctiva and corneal epithelium prior to and during cyclosporine- or tacrolimusbased treatment of keratoconjunctivitis sicca (KCS). The study was performed on 40 dogs with KCS. The dogs were divided into two groups of 20 animals each. In Group I, 0.75% cyclosporine eye drops were administered three times a day, while in Group II 0.02% tacrolimus eye drops were administered twice daily. Additionally, each group was subdivided into three subgroups based on the results of the Schirmer I tear test (STT I). Evaluation of cellular metaplasia in the cornea and the palpebral and bulbar conjunctiva based on the Nelson–Adams scale was performed by impression cytology using Millipore round filters (Millipore VSWP 01300 DA) of 25 μm pore diameter applied to the studied area. Ophthalmological and cytological examinations were performed prior to the treatment as well as after one and two months of therapy. In both groups, a decrease in Nelson–Adams values was observed, corresponding to the increasing STT values [Rxy Spearman statistically significant correlation coefficient values between –0.75 (P < 0.001) and –0.45 (P < 0.01)]. The absence of goblet cells was observed in all dogs, regardless of the KCS stage. Goblet cells reappeared following both tacrolimus- and cyclosporine-based treatment in impression cytology specimens classified as 0 in the Nelson–Adams scale. The extent of corneal and conjunctival metaplasia in the course of tacrolimus- and cyclosporine-based treatment of KCS decreases with increasing STT values.