Efficacy of inferior vena cava filters in anticoagulated patients.

BACKGROUND AND OBJECTIVES: The benefit of an inferior vena cava (IVC) filter in addition to standard anticoagulation regimens is unknown. METHODS: We examined data for patients who received IVC filters with anticoagulation (AC-Filter) after an episode of venous thromboembolism (VTE) and compared them with data for those who received anticoagulation only (AC-Only). Outcome measures were new pulmonary embolism (PE), recurrent deep vein thrombosis (DVT), and mortality at 90 days and at 5 years. Demographic data included age, gender, and ethnicity/race, prior thromboembolic history, cancer, serum albumin, and time in therapeutic range. In addition, subsets matched for age, gender and race/ethnicity were examined in detail. RESULTS: AC-Filter patients (n = 251), when compared to AC-Only patients (n = 1377), did not differ significantly with regard to gender or cancer status, but white males in general had better outcomes. AC-Filter patients were more likely to have had a previous history of PE or VTE (P < 0.001). In comparison to AC-Only patients, AC-Filter patients had lower mean serum albumin levels (3.1 +/- 0.8 vs. 3.6 +/-0.8 mg dL(-1), P < 0.001) and were older (65 +/- 16.1 years vs. 60 +/- 17.5 years, P < 0.001). After stratification according to previous history of PE or VTE prior to the index VTE event, no differences in the outcome measures of new PE, recurrent DVT or mortality were identified between groups, but patients with a prior history of PE from either group were more likely to have a new PE (hazard ratio 1.9, P < 0.001). CONCLUSIONS: These data suggest that IVC filters may not provide any substantial additional benefit for patients who can tolerate anticoagulant therapy.

[Hemothorax and ectopic pregnancy]. / Haemothorax og ektopisk graviditet.

Ectopic pregnancy presenting as haemothorax is extremely rare and difficult to handle. A case report concerning this problem is presented and a possible mechanism is discussed. The importance of bearing pregnancy in mind when fertile women present obscure symptoms is emphasized.

Demonstration of a neural network expert system for recognition of glaucomatous visual field changes.

Expert systems (ESs) are computer programs designed to make decisions in a manner similar to the way human experts make them. There are many forms of ESs, ranging from those that are given specific If-Then rules to those that are capable of deriving their own rules. Some ESs use neural network simulations to analyze patterns of data. In this project, a commercially available neural network shell program was used to demonstrate the development of an ES capable of analyzing the visual field loss patterns produced by glaucoma. Potential applications of ESs for the diagnosis of glaucoma are discussed.

[Supravaginal or total hysterectomy?]. / Supravaginal eller total hysterektomi?

There has been a decline in the rate of hysterectomies in Denmark in general over the last thirteen years, together with a rise in the number of supravaginal operations over the last two years. The literature concerning the relative merits of the supravaginal and the total abdominal operation is examined. It is concluded that the risk of developing carcinoma of the cervical stump is low, and no longer a weighty indication for the total in preference to the supravaginal hysterectomy as long as subsequent screening of the cervix is performed. At the same time it is important to inform the women carefully after the supravaginal operation in order to secure that subsequent screening actually is taking place. One must have a normal smear and offer a colposcopic examination before the operation. In general the rate of complications after both kind of hysterectomies is low. However, a few new studies indicate a reduced frequency of orgasm after the total hysterectomy compared with the supravaginal operation. When there are technical problems peroperatively with an increased urologic risk the supravaginal operation is recommended.

Tank crew vision.

Army optometrists stationed at The Armor Center, Fort Knox, identify the vision conservation needs and the functional visual requirements of each member of the tank crew. This article contains recommendations for vision conservation and for enhancement of visual function of the tank crewmen.

Automated decision making: the role of expert computer systems in the future of optometry.

BACKGROUND: Artificial intelligence (AI) refers to the ability of a machine, or system, or computer program to make intelligent decisions using the same methods that humans would use. By definition, and expert system (ES) is a computer program that uses knowledge and inference procedures to solve problems which would otherwise require the application of human expertise. METHODS: The role of expert systems in current and future applications in a number of fields were reviewed. RESULTS: Expert systems have and will be making an impact in many fields, including optometry in the future. CONCLUSIONS: Expert systems present an opportunity for the profession of optometry to become more efficient or accurate, provided that their development cost could be justified.

[Oophorectomy per occasionem and ovarian cancer]. / Oophorectomia per occasionem og ovariecancer.

The mortality from ovarian cancer is responsible for 450-500 cancer deaths annually in Denmark. This high mortality rate has remained unchanged for decades. No effective screening method is available. Oophorectomy per occasionem may reduce the incidence of ovarian cancer. The literature suggests a reduction in the incidence of ovarian cancer of 5.7% which corresponds to approximately 30 women annually in Denmark when OPO is performed at the age of forty or later. OPO also avoids reoperation due to the Residual Ovarian Syndrome, which is detected in approximately 2% of women after pelvic surgery.

Exploring the optometric application of expert computer systems: refractive error correction.

Using the commercially available shell programs NeuroShell and EXSYS, example-based and rule-based expert computer systems were developed to explore how such systems could be applied in an optometric environment. To demonstrate such an application, the example-based NeuroShell system was taught to prescribe sphere and cylinder powers for low refractive error myopes. When the system learned with only the chief complaint, habitual prescription and acuity through the habitual, and best refraction with resulting acuity, it predicted the sphere and cylinder powers prescribed by human optometrists within 0.25 diopter 97 and 98 percent of the time, respectively, for 60 test eyes. With a set of only three rules, the rule-based EXSYS system predicted sphere powers within 0.25 diopter of the prescribed powers for 100 percent of the 60 test eyes. Results with these very simple refractive problems suggest that teaching expert computer systems to prescribe ophthalmic lens corrections is possible, and further suggest that the concept could be extended to more complex and challenging patient populations.

Applications of expert computer systems.

An expert system is a computer program which uses artificial intelligence to make logical decisions on the basis of input data. The rules the system uses to make its decisions are called heuristics which can be provided in the form of IF . . . THEN statements, or they can be learned by the system from examples. The term "expert" is used because the rules or examples come from human experts and the program is considered to have captured their expertise. Currently there are many expert systems in business and medical use but few, if any, are used in optometry. The rule-oriented nature of many ophthalmic procedures suggests a future role for these systems, but their cost-effectiveness may not yet be favorable enough to justify development of expert systems for optometric practice.

Applications of catastrophe theory to optometry.

Catastrophe theory, a recently developed area of mathematics, is used to model two aspects of visual behavior. Visual behavior measured in a patient undergoing phorometry and the visual behavior of some patients with anomalous retinal correspondence undergoing the Walraven technique are characterized as catastrophes.