Performance Evaluation of STRATUS CS200 for Cardiac Markers

The STRATUS CS200 (Siemens Healthcare Diagnostics Inc., USA) has recently been developed as an on-site diagnostic instrument for assaying several kinds of cardiac markers within a short duration. The precision, linearity, comparison, limit of quantification, and turnaround time (TAT) were evaluated for troponin I, creatine kinase-MB (CK-MB), N-terminal pro-brain natriuretic peptide (NT-proBNP), and myoglobin assays according to guidelines provided by the Clinical and Laboratory Standards Institute. The total coefficients of variation of the four items were between 1.90% and 4.25%. All markers showed a linearity that was ≥0.99, and the values were within the manufacturer's range. All items showed a close correlation with E170 (Roche Diagnostics, Germany). The limits of quantification for troponin I, CK-MB, myoglobin, and NT-proBNP were 0.03 ng/mL, 0.3 ng/mL, 1 ng/mL, and 15 pg/mL, respectively. The TAT was 14 minutes. The performance of the STRATUS CS200 for assaying cardiac markers was highly satisfactory in terms of the precision, linearity, limit of quantification, and TAT, and it showed a good correlation with the comparative method.

Estratificación epidemiológica de riesgo / Epidemiological stratification of the risk

Fundamento: la estratificación la origina las unidades agregadas denominadas estratos, donde estas unidades presentan similitudes y diferencias entre sí. En diferentes países, la estratificación de riesgo emerge como enfoque estratégico. Desde la década de los 90 se ha incorporado al esquema de estratificación el enfoque epidemiológico de riesgo como base para la toma de decisiones. Objetivo: ofrecer elementos para la planificación y aplicación sobre la estratificación epidemiológica del riesgo. Método: se realizó un análisis bibliográfico que incluyó la búsqueda de investigaciones propias del tema así como documentos rectores y conferencias publicados, utilizando la herramienta artículos relacionados, en las bases de datos Medline-Pubmed, con el término estratificación epidemiológica del riesgo. Resultados: la bibliografía revisada coincide en la necesidad de aplicar los conceptos de estratificación epidemiológica de riesgo en el estudio de eventos sanitarios para la toma de decisiones. Se brindan elementos para la planificación y aplicación de la misma. Conclusiones: la decisión final sobre cuál método emplear y qué variables utilizar, se presenta como un dilema para el investigador, pues cualquiera de ellos puede servir perfectamente para los fines propuestos. Una vez conformados los estratos según la metodología escogida, se estará en condiciones de diseñar las estrategias de intervención para cada uno de ellos.

Background: aggregate units called stratums originate stratification; these units present similarities and differences among them. In some countries, the stratification of the risk appears as a strategic approach. Since the 90's, the epidemiological approach of the risk as a basis for the taking of decisions has been incorporated to the stratification system. Objective: to offer elements for the planning and application based on the epidemiological stratification of the risk. Method: a bibliographical analysis was conducted including the search of investigations related to the theme and published guiding documents and conferences. The tool of related articles was used to search in the data bases Medline and PubMed. The term used was epidemiological stratification of the risk. Results: the revised bibliography coincides with the necessity of applying the concepts of epidemiological stratification of the risk in the study of public health events for the taking of decisions. Elements for its planning and application are offered. Conclusions: the final decision about which method and variables to use is presented as a dilemma for the researchers since any of them can be perfectly good for the proposed aims. Once the stratums are made according to the chosen methodology, the conditions to design the strategies of intervention for each of them will be ready.

Changes of Peripapillary Retinal Nerve Fiber Layer Thickness Profile According to Aging in Myopic Eyes

PURPOSE: To evaluate the effects of age on the distributional variability of peripapillary retinal nerve fiber layer (RFNL) thickness measured by optical coherence tomography (OCT) in myopia. METHODS: Only the right eye of 64 myopic patients with long axial length (> or =24.5 mm) was included in the present study. The patients were divided into 2 age groups, 20 to 39 years of age and 40 to 59 years of age. Eventually, 42 subjects were selected and matched based on the difference of axial length not exceeding 0.5 mm between subjects in each group. The RFNL thickness was measured using Stratus OCT and average thickness, angular locations of double humps, and false-positive rate were compared. RESULTS: In both groups, the distribution of RNFL thickness in a double hump pattern was observed, which had a deviation to the temporal side only in the younger myopic eye group, but not in the middle-aged group. The middle-aged group had significantly thinner RNFL in 1, 7, and 8 clock-hour sectors compared to the younger myopic eyes (p < or = 0.02). Probability of abnormal OCT parameters at the 5% level of the 2 groups with the built-in RNFL normative database was not significantly different. CONCLUSIONS: The variability of RFNL thickness distribution related to axial length was less observed in the middle-aged group than the younger-aged group. These results should be considered in glaucoma diagnosis when using OCT.

Quantitative analysis of the Stratus optical coherence tomography fast macular thickness map reports.

The cross sectional optical coherence tomography images have an important role in evaluating retinal diseases. The reports generated by the Stratus fast macular thickness scan protocol are useful for both clinical and research purposes. The centerpoint thickness is an important outcome measure for many therapeutic trials related to macular disease. The data is susceptible to artifacts such as decentration and boundary line errors and could be potentially erroneous. An understanding of how the data is generated is essential before utilizing the data. This article describes the interpretation of the fast macular thickness map report, assessment of the quality of an optical coherence tomography image and identification of the artifacts that could influence the numeric data.

Usefulness of Table Parameters of Stratus OCT in Detection of Localized Retinal Nerve Fiber Layer Defects

PURPOSE: To evaluate the usefulness of table parameters of Stratus optical coherence tomography (OCT) in order to detect localized retinal nerve fiber layer (RNFL) defects. METHODS: The present study included 86 glaucoma patients with only localized, wedge-shaped RNFL defects, as determined by red-free RNFL photographs. All subjects were tested fast RNFL scans, using of Stratus OCT. The sensitivity of the clock hour parameter and 11 table parameters of RNFL thickness average analysis were compared. RESULTS: The best parameters in the superior table parameter of the Stratus OCT were Smax, Savg, and Smax/Tavg (sensitivity = 36.7%, 36.7%, 36.7%, respectively). The best parameters in the inferior table parameter of the Stratus OCT were Iavg, Imax, and Imax/Smax (sensitivity = 63.8%, 59.4%, and 50.7%, respectively). However, all were significantly lower than the sensitivity of the clock hour parameter (superior RNFL defect: 60%; inferior RNFL defect: 84.1%). CONCLUSIONS: The usefulness of the table parameters of the Stratus OCT used to detect localized RNFL defects in glaucoma patients is considered low because of its low sensitivity.

Comparison of Macular Thickness Measurements Between Fourier-Domain and Time-Domain Optical Coherence Tomography in Normal Eyes and Eyes With Macular Diseases

PURPOSE: To define and measure macular thickness and volume using Fourier domain OCT (FD OCT) and compare the values with Stratus OCT in normal eyes and eyes with macular disease. METHODS: On the same day, macular thicknesses of the ETDRS 9 subfield and total macular volumes were measured in 35 eyes of 23 normal subjects and 19 diseased eyes of 24 patients with FD OCT and Stratus OCT. The macular cube scan protocol for FD OCT and the fast macular thickness map protocol for Stratus OCT were used to measure macular thicknesses. RESULTS: Foveal thickness of the central subfield in FD OCT (251.49+/-79.45 micrometer) was thicker than the value of Stratus OCT (210.26+/-60.57 micrometer) (p<0.001) in all eyes. Total macular volume was 7.72+/-1.06 mm3 and 7.04+/-0.96 mm3 for FD OCT and Stratus OCT, respectively (p<0.001). Retina thickness of the ETDRS 9 subfields in FD OCT was thicker than the value obtained using Stratus OCT. In addition, foveal thickness differences were statistically significant in both the normal and diseased eye groups. CONCLUSIONS: Macular thickness and total macular volume as measured by the FD OCT were larger than the values obtained using the Stratus OCT in both the normal and the diseased eye groups. The measuring algorithm of FD OCT defines the top of RPE as the outer retinal boundary, but Stratus OCT defines the outer retinal boundary as the IS/OS junction of the photoreceptor. Therefore, macular thicknesses of FD OCT are thicker than those of Stratus OCT. This difference should be considered when comparing the results of FD OCT with those of Stratus OCT.

Comparison of Frequency Doubling Technology Perimeter and RNFL Photography for Early Diagnosis of Glaucoma

PURPOSE: To compare the frequency doubling technology perimeter (FDT) with retinal nerve fiber layer (RNFL) photography as a tool for the early detection of glaucoma. METHODS: Ninety-eight eyes of 98 patients were evaluated over a period of 3 months. According to the results of RNFL photography and FDT, Patients were divided into four groups based on the results of RNFL photography and optical coherence tomography (OCT). A comparison of the RNFL thickness of each group was performed using the OCT results. RESULTS: RNFL thickness in the group with abnormal FDT and normal RNFL were significantly decreased from those in the group with normal FDT and RNFL photography at the 6, 7 and, 10 o'clock area (p<0.05). CONCLUSIONS: There were statistically significant differences in the RNFL thickness between the group with abnormal FDT and normal RNFL photography, and the group with normal FDT and RNFL photography within the limited areas. These results imply that FDT is more useful for the early detection of glaucoma than RNFL photography.

Comparison of Time Domain OCT and Spectrum Domain OCT for Retinal Nerve Fiber Layer Assessment

PURPOSE: To compare retinal nerve fiber layer (RNFL) thickness obtained with Stratus optical coherence tomography (OCT) and Cirrus OCT. METHODS: Sixty-one normal eyes were evaluated with Stratus and Cirrus OCT on the same day, and the RNFL thicknesses measured by the two OCT machines were compared. The correlation between the two data sets was obtained using Pearson's correlation coefficient. The correlation between RNFL thickness and the difference in data measured by the two OCT machines was then assessed. RESULTS: The average RNFL thickness was significantly higher with Stratus OCT by 6.54+/-4.48 micrometer (p=0.0008). A strong correlation was present between the two RNFL thickness data sets (r=0.883), and the difference between Stratus and Cirrus values tended to increase as RNFL thickness increased. CONCLUSIONS: RNFL thickness measurements in normal eyes scanned with Cirrus OCT correlate well with Stratus OCT measurements. Average RNFL thickness was significantly higher with Stratus OCT, and as the RNFL thickness increased, the difference between Stratus and Cirrus values increased.

Structural and Functional Relationships in Glaucoma Using Standard Automated Perimetry and the Humphrey Matrix

PURPOSE: To evaluate and compare correlations between structural and functional loss in glaucoma as assessed by optical coherence tomography (OCT), scanning laser polarimetry (GDx VCC, as this was the model used in this study), standard automated perimetry (SAP), and the Humphrey Matrix (Matrix). METHODS: Ninety glaucomatous eyes identified with SAP and 112 eyes diagnosed using Matrix were independently classified into six subgroups, either S1/M1 (MD>-6dB), S2/M2 (-12

Stratus OCT, SWAP, Matrix FDT in Preperimetric Glaucoma

PURPOSE: To evaluate the peripapillary retinal nerve fiber layer (RNFL) thickness with optical coherence tomography (OCT) in normal subjects and preperimetric glaucoma patients, as well as compare the results of OCT, short wavelength automated perimetry (SWAP), frequency doubling technology perimetry (FDT) in preperimetric glaucoma patients. METHODS: Thirty-six eyes of 36 preperimetric glaucoma patients who have definitive localized RNFL defects in disc photograph and normal standard visual field, as well as 35 eyes of 35 normal subjects, were enrolled in this study. We compared the peripapillary RNFL thickness between the two groups using Stratus OCT. Stratus OCT, FDT, and SWAP results in preperimetric glaucoma group were also compared. RESULTS: Compared with normal controls, peripapillary RNFL thickness, including the average, superior, and inferior quadrant, was significantly low (P<0.05) in the preperimetric glaucoma group, 93.40+/-11.16 micrometer, 118.33+/-21.17 micrometer, and 108.72+/-16.76 micrometer respectively. In preperimetric glaucoma group, functional and structural abnormalities were found in 55.6% with Stratus OCT, 31.4% with SWAP, and 79.4% with Matrix FDT. CONCLUSIONS: Statistically significant reduction of RNFL thickness was revealed in the preperimetric glaucoma group, and Matrix FDT was the most sensitive test for detecting early glaucomatous change, followed by Stratus OCT, and SWAP.

Factors Influencing Optic Disc and Retinal Nerve Fiber Layer Parameters Measured by Optical Coherence Tomography

PURPOSE: To determine the factors influence retinal nerve fiber layer (RNFL) and optic nerve head (ONH) parameters measured by Stratus optical coherence tomography (OCT). METHODS: Topographic RNFL thickness and optic disc parameters of 129 healthy Korean subjects of aged 14 to 87 were measured using the fast retinal nerve fiber layer thickness and fast optic disk algorithms of Stratus OCT. One eye of each subject was randomly selected for statistical analysis. Using multiple linear regression, the effect of optic disc area, age, refractive error, and zone beta on each parameter was analyzed. RESULTS: Large discs had large horizontal integrated rim width (HIRW), cup area, rim area, C/D area ratio, and vertical C/D ratio. The thickness of average, superior, inferior, and nasal quadrant RNFL increased significantly with an increase in optic disc area. Average and superior quadrant RNFL thickness, and HIRW decreased with age. Refractive error showed a correlation with the vertical integrated rim area, horizontal C/D ratio, and temporal quadrant RNFL thickness. Gender and zone beta had no statistically significant influence on ONH and RNFL parameters. CONCLUSIONS: This study shows that optic disc size affects most RNFL thickness and ONH parameters. Because of the relationships revealed in this study, optic disc area in addition to age should be considered when the Stratus OCT RNFL thickness and ONH parameters are interpreted.

Comparison of the Results between Heidelberg Retina Tomography II and Stratus Optical Coherence Tomography in Glaucoma

PURPOSE: To evaluate the ability of Stratus OCT and HRT II with Moorfields' analysis to detect localized RNFL defects and to evaluate the accordance of Stratus OCT and HRT II results in glaucoma patients. METHODS: A total of 60 patients (119 eyes) who had localized RNFL defects of either eye in red-free fundus photographs unserwent evaluation by Stratus OCT and HRT II. For the results of Stratus OCT and HRT II with Moorfields' analysis, normal distribution percentiles less than 5% were considered a significant RNFL defect. For each disc, superotemporal and inferotemporal portions were evaluated. The diagnostic abilities of Stratus OCT and HRT II to detect localized RNFL defects were calculated. The results of HRT II were compared with those of Stratus OCT. RESULTS: The overall sensitivity, specificity, positive predictive value and negative predictive value to detect localized RNFL defects were 67.9%, 88.9%, 84.3% and 76.5% in Stratus OCT and 67.3%, 64.8%, 62.2% and 69.6% in HRT II, respectively. Compared with Stratus OCT, 67.2% of HRT II results were in accord in the superotemporal portion and 68.9% in the inferotemporal portion. The accordance of detection of RNFL defects between the two instruments in the inferotemoral portion was higher (79.2%) than others. CONCLUSIONS: Stratus OCT with a normative database is a useful aid to detect localized RNFL defects in early glaucoma. If observation of topographic changes of the optic disc with HRT II is added, results will be even better.

Diagnosis of Glaucoma in the Cases of the Opposed Results of GDx and OCT

PURPOSE: To investigate the coincidence of visual field loss in cases with different GDx VCC and Stratus OCT results, and to analyze the cause of these differences. METHODS: We retrospectively reviewed the medical records of patients who had visited our hospital for glaucoma evaluation from September 2003 to August 2005 for sensitivity, specificity, positive predictive rate, and negative predictive rate of GDx and OCT. In order to analyze the cause of discrepancy between the GDx and OCT results, we divided patients into Group A, consisting of GDx abnormal and OCT normal eyes, and Group B, consisting of GDx normal and OCT abnormal eyes. We compared optic disc tilting, peripapillary atrophy, and cup-disc ratio between the two groups. RESULTS: In cases of differing results between GDx and OCT, sensitivity, specificity, positive predictive rate and negative predictive rate were higher in Stratus OCT than in GDx. Peripapillary atrophy did not represent a statistically significant difference between group A and group B (p=0.601), where as the difference in cup-disc ratio between the two groups was statistically significant (p=0.000). CONCLUSIONS: OCT parameters coincided better than GDx with cases having different results on GDx and OCT. In cases with a large cup/disc ratio, there was a tendency to be normal according to GDx and abnormal by OCT.

The Stress Level According to the Working Status in the Migrant Workers / 대한산업의학회지

The number of foreign workers, which has increased since 1989, can be classified into industrial trainees and illegal migratory workers. As of January 1995, the official number of foreign workers reached 49,805 according to the Ministry of Labor. But the real number is estimated to be around 100,000 and industrial trainees are 22,583 among them. The stress induced by the culture shock, 3D (dirty, difficult and dangerous) working conditions, and illegal status of the foreign workers is greater than that of regular Korean workers. By using a psychological well-being index (PWI) measuring stress on 144 foreign workers, it was revealed that 68 people experienced "high risk stress", 76 "latent stress", and the average score was 62.8. The overall stress level was very high. Considering the distribution of high risk stress group and latent stress group by socio-demographic factors, the percentage of high risk stress group was higher among workers whose contract periods are less than 2 years than among workers whose contract periods are longer than 2 years. And the percentage of high risk stress group was higher when the number of workers at factory becoming larger, and also higher among workers who can not communicate well than among workers communicate well. After having a multiple stepwise regression analysis to find the socio-demographic factors which influence the PWI score, we found that the PWI score goes higher when the contract period is becoming shorter and the work hours is becoming longer, and these two factors are able to explain the score to the level 16.3%.