M.A. Albert

Comparison of Hemorrhagic Complications of Warfarin and Clopidogrel Bisulfate in 25-Gauge Vitrectomy versus a Control Group

PURPOSE To estimate the risk of hemorrhagic complications associated with 25-gauge pars plana vitrectomy (PPV) when warfarin (Coumadin; Bristol-Myers Squibb, New York, NY) or clopidogrel (Plavix; Bristol-Myers Squibb) are continued throughout the surgical period, as compared with a control group. DESIGN A single-center, retrospective, cohort study of 289 consecutive patients receiving either warfarin therapy or clopidogrel therapy or neither of those therapies who underwent 25-gauge PPV. PARTICIPANTS Included were 61 patients (64 eyes; 64 PPV procedures) in the warfarin group and 118 (125 eyes; 136 PPV procedures) in the clopidogrel group. Warfarin patients were subdivided into 4 groups by international normalized ratio (INR). A control group included 110 patients (110 eyes; 110 PPV procedures) who were not receiving warfarin or clopidogrel. METHODS Retrospective chart review for which the criteria included: 25-gauge PPV, minimum age of 19 years, warfarin or clopidogrel use, and, if taking warfarin, an INR obtained within 5 days of surgery. MAIN OUTCOME MEASURES Incidence of intraoperative and postoperative hemorrhagic complications. RESULTS The most common indications for anticoagulation therapy included: atrial fibrillation (38%), valvular heart disease (17%), and thromboembolic disease (16%). The most common indications for antiplatelet therapy included: cardiac stent (49%), coronary artery bypass grafting (24%), and history of transient ischemic attack (16%). No patient experienced anesthesia-related hemorrhagic complications resulting from peribulbar or retrobulbar block. Transient vitreous hemorrhage occurred in 1 (1.6%) of 64 PPV procedures in the warfarin group (P = 0.6531), 5 (3.7%) of 136 PPV procedures in the clopidogrel group (P = 1.0), and 4 (3.6%) of 110 PPV procedures in the control group. No choroidal or retrobulbar hemorrhages occurred in any patient. CONCLUSIONS The rate of 25-gauge PPV hemorrhagic complications in patients who underwent systemic anticoagulation or who were receiving platelet inhibitor therapy is extremely low. Given the risks associated with stopping these therapies, the authors recommend that patients continue their current therapeutic regimen without cessation.

Examining the association between age-related macular degeneration and motor vehicle collision involvement: a retrospective cohort study

Background Little is known about motor vehicle collision (MVC) risk in older drivers with age-related macular degeneration (AMD). The purpose of this study is to examine associations between MVC involvement and AMD presence and severity. Methods In a retrospective cohort study pooling the samples from four previous studies, we examined associations between MVC rate and older drivers with early, intermediate or advanced AMD as compared with those in normal eye health. MVC data were based on accident reports obtained from the state agency that compiles this information. Results MVC rate was highest among those in normal eye health and progressively declined among those with early and intermediate disease, and then increased for those with advanced AMD. However, only for drivers with intermediate AMD was the MVC rate significantly different (lower) as compared with those in normal eye health, regardless of whether the rate was defined in terms of person-years (RR 0.34, 95% CI 0.13 to 0.89) or person-miles (RR 0.35, 95% CI 0.13 to 0.91) of driving. Conclusions These results suggest that older drivers with intermediate AMD have a reduced risk of collision involvement. Further research should investigate whether self-regulatory driving practices by these drivers (avoiding challenging driving situations) underlies this reduced risk.