Prevalence of ocular hemorrhage in patients receiving warfarin therapy.

BACKGROUND: Warfarin, the drug most commonly used for outpatient anticoagulation therapy, has bleeding as its main side effect. The objective of this study was to determine the prevalence of ocular hemorrhage in patients receiving warfarin and to compare it to the prevalence in the general population. METHODS: Patients receiving warfarin therapy who were attending the anticoagulation clinic at a tertiary care hospital in Montreal between October and December 1996 received a flyer inviting them to have their eyes examined to look for "ocular bleeding." Consenting patients were examined for subconjunctival hemorrhage, gross hyphema, and vitreous and retinal hemorrhages through external ocular examination and funduscopic examination with the pupils dilated using direct and indirect ophthalmoscopy. RESULTS: Of the 1225 patients seen at the clinic 126 (10%) agreed to participate. Four patients (3%) were found to have intraretinal hemorrhage at the time of examination. All hemorrhages were visually insignificant. INTERPRETATION: The risk of retinal hemorrhage in patients without preexisting ocular disease, such as retinal neovascularization or choroidal vasculopathy, who are receiving warfarin therapy is so small that it should not deter physicians from prescribing this drug when indicated.

Experimental determination of dosimetry functions of Ir-192 sources.

Experimental data related to the dosimetric characteristics of Ir-192 brachytherapy sources are limited. The aim of this work was to obtain the dosimetry functions required by the American Association of Physicists in Medicine Task Group 43 for both a low and a high dose-rate iridium-192 brachytherapy source through dose measurements in a water-equivalent phantom. Dose measurements have been performed using lithium fluoride thermoluminescent detectors positioned in a polystyrene phantom at distances from the source that vary from 1 to 10 cm, with 1 cm intervals, and at angles that vary from 0 degree to 170 degrees with 10 degrees intervals. The anisotropy functions, radial dose functions, and dose rate constants were determined for both brachytherapy sources. The precision of results obtained on those relatively fine intervals of angles and distances provides clinics with the possibility to use and interpolate the complete data sets for treatment planning.

Psychological characteristics of volunteers in studies on gambling.

Advertisements were published in local newspapers asking for volunteers to participate in a study on gambling. A battery of eleven questionnaires was mailed to the subjects assessing pathological gambling behavior, sociodemographic characteristics, motivation to gamble, erroneous perceptions about gambling, superstitious beliefs, depressive symptoms, social anxiety and avoidance, alcohol and drug abuse, problem-solving skills, and marital satisfaction. Subjects received $10 when they returned the questionnaires fully completed. Response rate was over 95%. Surprisingly, 29% of the respondents met the criterion for probable pathological gambling (score of 5 or more on the SOGS) and a further 16% were identified as potential pathological gamblers (scores of 3 or 4). The potential and probable pathological gamblers showed significant differences on motivational and cognitive variables related to gambling compared to those subjects who showed no signs of pathological gambling. The probable pathological gamblers reported significantly more signs of poor psychosocial functioning than the other two groups, including depressive symptoms, poor problem orientation, drug and alcohol abuse, and interpersonal conflict. The practical and theoretical implications of these results are discussed.