Evaluation of photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL) in feline infectious keratitis-patient demographics, treatment protocols, risk factors, and treatment outcome: a retrospective study.

OBJECTIVES: To describe patient demographics and treatment protocols in a population of feline patients undergoing photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL) as an adjunctive treatment for infectious keratitis. Furthermore, to determine the proportion of PACK-CXL treatment success in the population studied, explore risk factors for treatment failure, and provide recommendations for future PACK-CXL clinical studies. MATERIALS AND METHODS: Records from four veterinary ophthalmology practices were reviewed to identify eligible patients and extract data. Recorded variables included patient-related factors, ocular examination findings, PACK-CXL protocol parameters, and treatment outcome. RESULTS: Records for 153 cats (154 eyes) were included. Median age in the treatment success group was 8 years (interquartile range (IQR) 4-12), with a median ulcer depth of 30% (IQR 30-40). Median age in the treatment failure group was 10.5 years (IQR 4.75-12) with a median ulcer depth of 45.9% (IQR 30-75). Persian cats were the most represented brachycephalic breed (52 out of 64 cats). Modified PACK-CXL protocols were used, including fast energy delivery (134 eyes), and increased fluence (52 eyes). The overall proportion of success was 88% (95% CI 84-93), which was variable between clinics. Eighty-two of 89 mesocephalic cat eyes (92%), and 54 of 65 brachycephalic cat eyes (83%) were classified as treatment successes. CONCLUSIONS: PACK-CXL appeared to be a useful, adjunctive therapeutic modality for the treatment of infectious keratitis in the feline patient population presented here. Brachycephalic cats, older cats, and those with deeper ulcers may be at increased risk for treatment failure.

Fibrinolytic Capacity of Desmoteplase Compared to Tissue Plasminogen Activator in Rabbit Eyes.

PURPOSE: Desmoteplase (DSPA) was evaluated and compared with tissue plasminogen activator (t-PA) for its intraocular fibrinolytic effect and short-term toxicity in an in vivo study using rabbit eyes. METHODS: Fibrin clots were induced in the anterior chamber of 44 rabbit eyes, and drug efficacy was measured by clot size reduction over 24 h. Topical DSPA eye drops (1.4 and 2 mg/mL) were compared with vehicle solution in a multiple-drop regimen in 8 animals per group. Intracameral injections of 0.6 µg DSPA (n = 14) and 25 µg t-PA (n = 14) were evaluated for their fibrinolytic efficacy. Animals were euthanized 24 h after drug application. RESULTS: No significant differences were seen between topically treated DSPA and vehicle-treated animals. Intracameral t-PA had a higher fibrinolytic efficacy than DSPA at early time points, but no significant difference was seen between both groups at 24-h postapplication. Animals with t-PA treatment demonstrated significantly more side effects compared with DSPA-treated animals. DSPA showed no-to-mild side effects after topical and intracameral treatment. Histologically, no toxic effects were observed in any globe. CONCLUSIONS: DSPA is a promising drug with fewer side effects and similar fibrinolytic efficacy compared with t-PA 24 h after intracameral application in rabbit eyes at the tested concentration. Drug efficacy might be improved by increasing intracameral DSPA doses.

Septic keratitis in dogs, cats, and horses in Switzerland: associated bacteria and antibiotic susceptibility.

OBJECTIVE: To evaluate the most common bacterial pathogens associated with septic keratitis in veterinary patients from Switzerland. The second objective was to analyze antibiotic susceptibility test results of the identified bacterial pathogens. The third objective was to evaluate potential breed predispositions to septic keratitis. PROCEDURES: Two hundred and fifty-five cultures and antibiotic susceptibility reports from dogs, cats, and horses with septic keratitis that were presented to the University of Zurich Veterinary Medical Teaching Hospital between 2009 and 2013 were reviewed. Odds ratios for the risk of having a septic keratitis were estimated for all dog and cat breeds compared to the general nonbrachycephalic hospital population. RESULTS: Ninety-six, 29, and 31 positive cultures were obtained from 89 canine, 28 feline, and 29 equine eyes, respectively. Repeat sampling accounted for the differences in numbers. Negative culture results were obtained in 50, 31, and 18 cases. Staphylococci and streptococci accounted for 66% of the isolates in dogs and 80% of the isolates in cats and horses. Staphylococcus spp. had a higher percentage of fluoroquinolone-resistant isolates compared to previous reports. Brachycephalic breeds had elevated odds ratios for the presence of septic keratitis. CONCLUSION: Identified bacterial pathogens and their prevalence as well as the elevated odds ratios for septic keratitis in brachycephalics are roughly consistent with previous studies. Based on systemic breakpoint data, resistance to commonly used topical antibiotics, including the second-generation fluoroquinolones, was found.