The relationship of alignment hyperacuity to stereopsis

The term alignment hyperacuity , a monocularly measured entity, is functionally described as the ability to detect an alignment of two points in space. It produces spatial thresholds usually 8 to 13 arc seconds of visual angle, which is smaller than those expected given the relatively large receptor density of the human retina. It has not been firmly established whether or not alignment hyperacuity performance is related to threshold stereopsis. This study examines the correlation between threshold stereoacuity and the sum of right and left eyes\u27 monocular alignment detection hyperacuity measures. Twenty-one subjects were evaluated measuring threshold stereoacuity with the Mentor BVAT II and monocular alignment hyperacuity with software designed at Pacific University College of Optometry. This study indicates that the sum of each eyes\u27 alignment hyperacuity data should be equal to or slightly less sensitive (greater value) than an individual\u27s threshold stereoacuity. The lack of valid baseline knowledge about alignment detection hyperacuity and its relation to threshold stereopsis may be withholding optometric practitioners from understanding and/or testing certain aspects of alignment hyperacuity that might be of importance clinically including unexplained asthenopia, monitoring improvements in amblyopic therapy, and predicting potential stereoacuity in anti-strabismic treatment

Prognostic Significance of Hemodynamic Parameters in Patients with Cardiogenic Shock.

BACKGROUND: Invasive hemodynamic assessment with a pulmonary artery catheter is often used to guide management of patients with cardiogenic shock (CS) and may provide important prognostic information. We aimed to assess prognostic associations and relationships to end-organ dysfunction of presenting hemodynamic parameters in CS. METHODS: The Critical Care Cardiology Trials Network (CCCTN) is an investigator-initiated multicenter registry of cardiac intensive care units (CICUs) in North America coordinated by the TIMI Study Group. Patients with CS (2018-2022) who underwent invasive hemodynamic assessment within 24 hours of CICU admission were included. Associations of hemodynamic parameters with in-hospital mortality were assessed using logistic regression, and associations with presenting serum lactate were assessed using least squares means regression. Sensitivity analyses were performed excluding patients on temporary mechanical circulatory support and adjusted for vasoactive-inotropic score. RESULTS: Among the 3,603 admissions with CS, 1,473 had hemodynamic data collected within 24 hours of CICU admission. Median cardiac index was 1.9 (IQR, 1.6-2.4) L/min/m2 and mean arterial pressure (MAP) was 74 (66-86) mmHg. Parameters associated with mortality included low MAP, low systolic blood pressure, low systemic vascular resistance, elevated right atrial pressure (RAP), elevated RAP/pulmonary capillary wedge pressure ratio, and low pulmonary artery pulsatility index. These associations were generally consistent when controlling for intensity of background pharmacologic and mechanical hemodynamic support. These parameters were also associated with higher presenting serum lactate. CONCLUSIONS: In a contemporary CS population, presenting hemodynamic parameters reflecting decreased systemic arterial tone and indicators of right ventricular dysfunction are associated with adverse outcomes and presenting lactate