A study of pupillary assessment in outpatient neurosurgical clinics.

This study compared the accuracy of three methods of assessing pupil diameter Measurements from the ForSite pupillometer and visual assessments were compared with measurements obtained using a pupil gauge (the standard method). Two sets of measurements were obtained from 65 out-patients at four neurosurgical clinics. The correlation between the three methods showed significance; however, the pupil gauge measurements showed a more significant correlation with measurements from the pupillometer than with visual assessments. Pupil diameter measurements from the pupillometer were larger than those from either the pupil gauge or clinical observation. We conclude that the ForSite pupillometer is an easy-to-use and accurate measure of pupil diameter in a clinic setting. It may be more accurate than the pupil gauge.

Quantitative pupillometry, a new technology: normative data and preliminary observations in patients with acute head injury. Technical note.

The authors prospectively used a new hand-held point-and-shoot pupillometer to assess pupillary function quantitatively. Repetitive measurements were initially made in more than 300 healthy volunteers ranging in age from 1 to 87 years, providing a total of 2,432 paired (alternative right eye, left eye) measurements under varying light conditions. The authors studied 17 patients undergoing a variety of nonintracranial, nonophthalmological, endoscopic, or surgical procedures and 20 seniors in a cardiology clinic to learn more about the effects of a variety of drugs. Additionally, the authors carried out detailed studies in 26 adults with acute severe head injury in whom intracranial pressure (ICP) was continuously monitored. Finally, five patients suffering from subarachnoid hemorrhage were also studied. Quantitative pupillary measurements could be reliably replicated in the study participants. In healthy volunteers the resting pupillary aperture averaged 4.1 mm and the minimal aperture after stimulation was 2.7 mm, resulting in a 34% change in pupil size. Constriction velocity averaged 1.48 +/- 0.33 mm/second. Pupillary symmetry was striking in both healthy volunteers and patients without intracranial or uncorrected visual acuity disorders. In the 2,432 paired measurements in healthy volunteers, constriction velocity was noted to fall below 0.85 mm/second on only 33 occasions and below 0.6 mm/second on eight occasions (< one in 310 observations). In outpatients, the reduction in constriction velocity was observed when either oral or intravenous narcotic agents and diazepam analogs were administered. These effects were transient and always symmetrical. Among the 26 patients with head injuries, eight were found to have elevations of ICP above 20 mm Hg and pupillary dynamics in each of these patients remained normal. In 13 patients with a midline shift greater than 3 mm, elevations of ICP above 20 mm Hg, when present for 15 minutes, were frequently associated with a reduction in constriction velocity on the side of the mass effect to below 0.6 mm/second (51% of 156 paired observations). In five patients with diffuse brain swelling but no midline shift, a reduction in constriction velocities did not generally occur until the ICP exceeded 30 mm Hg. Changes in the percentage of reduction from the resting state following stimulation were always greater than 10%, even in patients receiving large doses of morphine and propofol in whom the ICP was lower than 20 mm Hg. Asymmetry of pupillary size greater than 0.5 mm was observed infrequently (< 1%) in healthy volunteers and was rarely seen in head-injured patients unless the ICP exceeded 20 mm Hg. Pupillometry is a reliable technology capable of providing repetitive data on quantitative pupillary function in states of health and disease.

Characterization of circulating endothelial cells in acute myocardial infarction.

Acute myocardial infarction (MI), which involves the rupture of existing atheromatous plaque, remains highly unpredictable despite recent advances in the diagnosis and treatment of coronary artery disease. Accordingly, a clinical measurement that can predict an impending MI is desperately needed. Here, we characterize circulating endothelial cells (CECs) using an automated and clinically feasible CEC three-channel fluorescence microscopy assay in 50 consecutive patients with ST-segment elevation MI and 44 consecutive healthy controls. CEC counts were significantly elevated in MI cases versus controls, with median numbers of 19 and 4 cells/ml, respectively (P = 1.1 × 10(-10)). A receiver-operating characteristic (ROC) curve analysis demonstrated an area under the ROC curve of 0.95, suggesting near-dichotomization of MI cases versus controls. We observed no correlation between CECs and typical markers of myocardial necrosis (ρ = 0.02, creatine kinase-myocardial band; ρ = -0.03, troponin). Morphological analysis of the microscopy images of CECs revealed a 2.5-fold increase (P < 0.0001) in cellular area and a twofold increase (P < 0.0001) in nuclear area of MI CECs versus healthy controls, age-matched CECs, as well as CECs obtained from patients with preexisting peripheral vascular disease. The distribution of CEC images that contained from 2 to 10 nuclei demonstrates that MI patients were the only subject group to contain more than 3 nuclei per image, indicating that multicellular and multinuclear clusters are specific for acute MI. These data indicate that CEC counts may serve as a promising clinical measure for the prediction of atherosclerotic plaque rupture events.