Variation in intraocular pressure following application of tropicamide in three different dog breeds.

OBJECTIVE: To record intraocular pressure (IOP) of three different dog breeds following administration of one drop of 1% tropicamide. ANIMALS: Three dog breeds -- Golden Retrievers (n = 20), Siberian Huskies (n = 20) and English Cocker Spaniels (n = 36) -- were studied. PROCEDURE: IOPs were measured using a Tonopen following corneal anesthesia with a single drop of 0.5% proxymetacaine. A drop of 0.5% tropicamide was then administered bilaterally and a second IOP measurement was taken 30 min later (postdilation). The difference between the two measurements was considered as the effect of mydriasis on IOP. RESULTS: Dogs had an average IOP of 14.9 +/- 3.2 mmHg, with 95% confidence limits ranging from 8 to 22 mmHg. There were significant differences between breeds (P < 0.006) with Siberian Huskies having higher IOPs (17.2 +/- 3.7 mmHg) than the other breeds (Spaniels: 14.2 +/- 2.8 mmHg, P < 0.01; Retrievers: 14 +/- 1.9 mmHg, P < 0.001). The majority (60%) of dogs displayed 5 mmHg or less in IOP change postmydriasis. Siberian Huskies showed the highest IOP levels, and also had the greatest variability with dilation. CONCLUSIONS AND CLINICAL RELEVANCE: Interbreed variability in effect of tropicamide of canine IOP is evident.

Contemporary issues in clopidogrel therapy: new evidence shaping clinical practice.

Antiplatelet therapy is a cornerstone in the management of acute coronary syndromes. Clopidogrel produces irreversible inhibition of the platelet adenosine diphosphate receptor, thereby attenuating activation and aggregation of platelets. Clopidogrel has been shown to prevent stent thrombosis in patients undergoing percutaneous coronary intervention (PCI) and reduces major adverse cardiovascular events in patients with unstable angina or non-ST-segment elevation myocardial infarction (non-STEMI). Recent studies have left clinicians with many questions regarding the role and dosing regimens of clopidogrel in STEMI, PCI, and primary or secondary prevention. Based on an analysis of the data, clopidogrel should be given in addition to aspirin and fibrinolytic therapy to patients with STEMI. In patients undergoing PCI, a loading dose of clopidogrel 600 mg should be given if the procedure needs to be performed within 15 hours of initial presentation. If PCI can be delayed for 15 hours or more, a loading dose of 300 mg can be used. Evidence also suggests that clopidogrel should not be prescribed for primary prevention in high-risk patients.