Purpose: To evaluate the test-retest reliability of a contour-based stereoacuity test using a head-mounted display (HMD) and compare it with other stereotests. Methods: Thirty-two healthy adults aged 23-47 years were recruited from a tertiary hospital between August 2017 and July 2018. Two separate contour-based circles (crossed disparity: 135-1,350 arcsecs) were generated on a high-resolution phone display (Galaxy S7; Samsung, Seoul, Korea) using an HMD (Galaxy Gear VR). Two images were independently projected to each eye as graded circles with a random dot background. The results of the new HMD stereotest were compared to those of the standard Randot and TNO stereotests. The test-retest reliability was assessed using the Bland-Altman plot and Cohen’s kappa statistics. Results: Among the 32 study participants, 17 (53%) were males and the mean age was 30.1 ± 4.8 years (range: 23-47). The mean stereoacuity was 160.3 ± 53.5 arcsecs in the first HMD stereotest (HMD1), 28.4 ± 12.5 arcsecs in the Randot stereotest, 96.1 ± 83.5 arcsecs in the TNO stereotest, and 143.3 ± 47.7 arcsecs in the second HMD stereotest (HMD2). The Bland-Altman plot showed a mean difference of 0.042 (-0.189 to +0.272, 95% limits of agreement) between HMD1 and HMD2. The reliability analysis showed an intraclass correlation coefficient of 0.499 (p = 0.022) and agreement of 81.25% in Cohen’s kappa statistics (Cohen’s kappa index = 0.119, p = 0.017). Conclusions The HMD stereotest without monocular cues showed fair test-retest reliability and reproducibility. Further studies using a high resolution display are needed to confirm the validity of the HMD stereotest.

BACKGROUND: From May to July 2015, the Republic of Korea experienced the largest outbreak of Middle East respiratory syndrome (MERS) outside the Arabian Peninsula. A total of 186 patients, including 36 deaths, had been diagnosed with MERS-coronavirus (MERS-CoV) infection as of September 30th, 2015. MATERIALS AND METHODS: We obtained information of patients who were confirmed to have MERS-CoV infection. MERS-CoV infection was diagnosed using real-time reverse-transcriptase polymerase chain reaction assay. RESULTS: The median age of the patients was 55 years (range, 16 to 86). A total of 55.4% of the patients had one or more coexisting medical conditions. The most common symptom was fever (95.2%). At admission, leukopenia (42.6%), thrombocytopenia (46.6%), and elevation of aspartate aminotransferase (42.7%) were observed. Pneumonia was detected in 68.3% of patients at admission and developed in 80.8% during the disease course. Antiviral agents were used for 74.7% of patients. Mechanical ventilation, extracorporeal membrane oxygenation, and convalescent serum were employed for 24.5%, 7.1%, and 3.8% of patients, respectively. Older age, presence of coexisting medical conditions including diabetes or chronic lung disease, presence of dyspnea, hypotension, and leukocytosis at admission, and the use of mechanical ventilation were revealed to be independent predictors of death. CONCLUSION: The clinical features of MERS-CoV infection in the Republic of Korea were similar to those of previous outbreaks in the Middle East. However, the overall mortality rate (20.4%) was lower than that in previous reports. Enhanced surveillance and active management of patients during the outbreak may have resulted in improved outcomes.
Antiviral Agents ; Aspartate Aminotransferases ; Coronavirus Infections* ; Disease Outbreaks ; Dyspnea ; Extracorporeal Membrane Oxygenation ; Fever ; Humans ; Hypotension ; Leukocytosis ; Leukopenia ; Lung Diseases ; Middle East Respiratory Syndrome Coronavirus ; Middle East* ; Mortality ; Pneumonia ; Polymerase Chain Reaction ; Republic of Korea* ; Respiration, Artificial ; Thrombocytopenia

BACKGROUND/AIMS: A subset of patients may develop colorectal cancer after a colonoscopy that was negative for carcinoma. These missed or de novo developed lesions were termed as interval cancers. Many studies regarding interval cancer have been conducted in Western countries, whereas very limited data are available in Asian populations. Therefore, the purpose of this study was to investigate prevalence, clinicopathologic features, and predictors of interval colorectal cancers in the Korean population. METHODS: Interval cancer was defined as a cancer that is diagnosed within 5 years of a negative colonoscopy result. Among the patients who were diagnosed colorectal cancers at Kangbuk Samsung Hospital from January 2007 to April 2012, clinicopathologic characteristics of interval cancers were compared with those of sporadic cancers. RESULTS: Among the 785 patients, 482 responded to telephone calls. Of these, 30 (6.2%) developed interval cancers. Finally, 28 patients who had interval cancers were compared with 415 patients who had sporadic cancers. Interval cancer group was significantly younger and more frequent in the right side colon than sporadic cancer group. There was no differences in sex, tumor size, differentiation, and staging between two groups. In multivariate analysis, young age and right side colon cancer were independent factors associated with an interval cancer. CONCLUSIONS: A significant proportion of Korean patients developed interval colorectal cancer, especially at the young age and in the proximal colon.
Asian Continental Ancestry Group ; Colon ; Colonic Neoplasms ; Colonoscopy ; Colorectal Neoplasms ; Humans ; Multivariate Analysis ; Prevalence ; Telephone

The pneumonia severity index (PSI) and CURB-65 are widely used tools for the prediction of community-acquired pneumonia (CAP). This study was conducted to evaluate validation of severity scoring system including the PSI and CURB-65 scores of Korean CAP patients. In the prospective CAP cohort (participated in by 14 hospitals in Korea from January 2009 to September 2011), 883 patients aged over 18 yr were studied. The 30-day mortalities of all patients were calculated with their PSI index classes and CURB scores. The overall mortality rate was 4.5% (40/883). The mortality rates per CURB-65 score were as follows: score 0, 2.3% (6/260); score 1, 4.0% (12/300); score 2, 6.0% (13/216); score 3, 5.7% (5/88); score 4, 23.5% (4/17); and score 5, 0% (0/2). Mortality rate with PSI risk class were as follows: I, 2.3% (4/174); II, 2.7% (5/182); III, 2.3% (5/213); IV, 4.5% (11/245); and V, 21.7% (15/69). The subgroup mortality rate of Korean CAP patients varies based on the severity scores and CURB-65 is more valid for the lower scores, and PSI, for the higher scores. Thus, these variations must be considered when using PSI and CURB-65 for CAP in Korean patients.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; Cohort Studies ; Community-Acquired Infections/*mortality ; Female ; Humans ; Intensive Care Units ; Male ; Middle Aged ; Pneumonia/*mortality ; Prospective Studies ; Republic of Korea ; *Severity of Illness Index ; Young Adult

BACKGROUND/AIMS: The red-blood-cell distribution width (RDW) is a newly recognized risk marker in patients with cardiovascular disease, but its role in nonalcoholic fatty liver disease (NAFLD) has not been well defined. The aim of the present study was to determine the association between RDW values and the level of fibrosis in NAFLD according to BARD and FIB-4 scores. METHODS: This study included 24,547 subjects who had been diagnosed with NAFLD based on abdominal ultrasonography and questionnaires about alcohol consumption. The degree of liver fibrosis was determined according to BARD and FIB-4 scores. The association between RDW values and the degree of fibrosis in NAFLD was analyzed retrospectively. RESULTS: After adjusting for age, hemoglobin level, mean corpuscular volume, history of hypertension, history of diabetes, and high-sensitivity C-reactive protein, the RDW values were 12.61+/-0.41% (mean+/-SD), 12.70+/-0.70%, 12.77+/-0.62%, 12.87+/-0.82%, and 13.25+/-0.90% for those with BARD scores of 0, 1, 2, 3, and 4, respectively, and 12.71+/-0.72%, 12.79+/-0.66%, and 13.23+/-1.52% for those with FIB-4 scores of <1.30, 1.31-2.66, and > or =2.67, respectively (P<0.05). The prevalence of advanced fibrosis (BARD score of 24 and FIB-4 score of > or =1.3) increased with the RDW [BARD score: 51.1% in quartile 1 (Q1) vs. 63.6% in Q4; FIB-4 score: 6.9% in Q1 vs. 10.5% in Q4; P<0.001]. After adjustments, the odds ratio of having advanced fibrosis for those in Q4 compared to Q1 were 1.76 (95%CI=1.55-2.00, P<0.001) relative to BARD score and 1.69 (95%CI=1.52-1.98, P<0.001) relative to FIB-4 score. CONCLUSIONS: Elevated RDW is independently associated with advanced fibrosis in NAFLD.
Adult ; Alcohol Drinking ; C-Reactive Protein/analysis ; Diabetes Mellitus/pathology ; Erythrocyte Indices ; Fatty Liver/complications/*diagnosis/ultrasonography ; Female ; Humans ; Hypertension/pathology ; Liver Cirrhosis/*diagnosis/epidemiology/etiology ; Male ; Middle Aged ; Odds Ratio ; Prevalence ; Questionnaires ; Severity of Illness Index

Wernicke's encephalopathy is a relatively underestimated disorder caused by a deficiency of thiamine and manifests with a classical triad of ocular abnormalities, ataxia, and mental-status changes. Specific laboratory tests are unavailable and the disease remains a clinical diagnosis. Among paraclinical studies, magnetic resonance imaging is currently considered the most valuable method to confirm a diagnosis of Wernicke's encephalopathy. Treatment is based on supplementation of thiamine that is administered parentally. We report a case of Wernicke's encephalopathy that was treated with thiamine and showed the characteristic clinical findings, as well as an extremely rare symptom of severe dysphagia that improved concurrently with neurological recovery. Only a few cases of dysphagia in Wernicke's encephalopathy have been reported worldwide.
Ataxia ; Deglutition Disorders ; Humans ; Magnetic Resonance Imaging ; Parents ; Thiamine ; Thiamine Deficiency ; Wernicke Encephalopathy

Atlantoaxial subluxation in undifferentiated spondyloarthropathy is extremely rare and has not been reported. We describe a case of 27-year-old man who was diagnosed as undifferentiated spondyloarthropathy with atlantoaxial subluxation with an initial complaint of painful swelling of right 1st metatarsophalangeal joint and posterior neck pain. Roentgenograms showed sclerotic change and increased hazziness in right 1st metatarsophalangeal joint. Magnetic resonance images and roentgenograms of the cervical spine showed inflammation of odontoid process and atlantoaxial subluxation. Bone scan showed hot uptakes in left sacroiliac joint, right 1st & 4th metacarpophalangeal joints and 1st metatarsophalangeal joint. HLA-B27 gene was positive. Spontaneous atlantoaxial subluxation and undifferentiated spondyloarthropathy was diagnosed and conservatively treated with oral medication. Currently, there is no definite neurological sign. Early recognition and awareness of potential clinical complications is important in preventing compressive damage on central nervous system.
Adult ; Central Nervous System ; HLA-B27 Antigen ; Humans ; Inflammation ; Magnetic Resonance Spectroscopy ; Metacarpophalangeal Joint ; Metatarsophalangeal Joint ; Neck Pain ; Odontoid Process ; Sacroiliac Joint ; Spine ; Spondylarthropathies

OBJECTIVES: After the investigation of one worker with occupational asthma, we surveyed the prevalence of occupational asthma and the exposure level of pharmaceutical dust of 32 workers in a pharmaceutical company. METHODS: Thirty-two of the 90 employees participated in the survey which consisted of questionnaire, blood sampling, spirometry and skin prick tests with 8 common allergens as well as 9 antibiotics and 2 enzymes. Various indices of the working environment were also measured. Subjects who had a symptom suggestive of work-related asthma or positive skin prick test were further investigated by PC20 methacholine. Nine subjects who had a PC20 result of 16 mg/ml or less (n=7) or had work-related symptoms and positive skin prick test (n=2) were referred to undergo a specific bronchial provocation test to pharmaceutical dust in an academic allergic disease center. RESULTS: Eleven of 32 workers (34.4%) had a work-related symptom suggestive of occupational asthma. Ten (31.2%) showed positive skin prick test. 8 (25.0%) had a PC20 result of 16 mg/ml or less (indicative of significant bronchial hyperresponsiveness), and 5 (15.6%) had a positive result on the specific bronchial provocation test. Exposure levels of stuffing, input of raw materials and screening process were relatively high. CONCLUSIONS: This survey showed that pharmaceutical workers have an increased risk of occupational asthma. Although pharmaceutical factories maintain a relatively good working environment, careful control of respiratory tract exposures, especially during stuffing, input of raw materials and screening process, is important to prevent occupational asthma. Pharmaceutical workers need to undergo regular skin prick and methacholine bronchial provocation tests, as well as asthmatic symptom survey, to ensure the early detection and prevention of occupational asthma.
Allergens ; Anti-Bacterial Agents ; Asthma ; Asthma, Occupational* ; Bronchial Provocation Tests ; Dust* ; Mass Screening ; Methacholine Chloride ; Prevalence* ; Questionnaires ; Respiratory System ; Skin ; Spirometry

BACKGROUND: Post-transplantation lymphoproliferative disorder (PTLD) after liver transplantation is a rare but potentially fatal disease. Clinical manifestations and prevalence of PTLD after liver transplantation in Korea have not been investigated thoroughly. MATERIALS AND METHODS: A retrospective chart review was done for 284 liver transplant recipients at Samsung Medical Center, Seoul, Korea during the period from 1996 to 2003. RESULTS: The incidence of PTLD after liver transplantation was 3.9% (11/284). PTLDs were more prevalent in children (9/55, 16.4%) than in adults (2/237, 0.9%; P<0.01). Among the PTLD patients, four cases were male (36.3%) and seven were female (63.7%). Median time from the transplantation to PTLD diagnosis was 9 months. The type of PTLD was as follows:early lesion (6 cases, 54.5%), polymorphic PTLD (3 cases, 27.3%), and B cell lymphoma (2 cases, 18.2%). PTLDs were more prevalent in the patients with cyclosporine use (OR 13.28, 95% CI:1.29-136.31, P=0.03), acute rejection (OR 5.63, 95% CI:1.03-30.62, P=0.04), and negative serology for EBV VCA IgG (OR 19.15, 95% CI:1.99-183.98, P=0.01) by multivariate logistic regression. Three patients (27.3%) died of B cell lymphoma (2 cases) and polymorphic PTLD (1 case). The remaining patients were improved with reduction of immunosuppression and treatment with acyclovir. CONCLUSION: The incidence of PTLD was high in children. The risk factors of PTLD were negative serology for EBV VCA IgG, history of acute rejection, and cyclosporine use. Considering the poor prognosis of PTLD, effective strategies for prevention and early diagnosis for early treatment should be emphasized.
Acyclovir ; Adult ; Child ; Cyclosporine ; Diagnosis ; Early Diagnosis ; Female ; Herpesvirus 4, Human ; Humans ; Immunoglobulin G ; Immunosuppression ; Incidence ; Korea ; Liver Transplantation* ; Liver* ; Logistic Models ; Lymphoma, B-Cell ; Lymphoproliferative Disorders* ; Male ; Prevalence ; Prognosis ; Retrospective Studies ; Risk Factors ; Seoul ; Transplantation

BACKGROUND: Post-transplantation lymphoproliferative disorder (PTLD) after liver transplantation is a rare but potentially fatal disease. Clinical manifestations and prevalence of PTLD after liver transplantation in Korea have not been investigated thoroughly. MATERIALS AND METHODS: A retrospective chart review was done for 284 liver transplant recipients at Samsung Medical Center, Seoul, Korea during the period from 1996 to 2003. RESULTS: The incidence of PTLD after liver transplantation was 3.9% (11/284). PTLDs were more prevalent in children (9/55, 16.4%) than in adults (2/237, 0.9%; P<0.01). Among the PTLD patients, four cases were male (36.3%) and seven were female (63.7%). Median time from the transplantation to PTLD diagnosis was 9 months. The type of PTLD was as follows:early lesion (6 cases, 54.5%), polymorphic PTLD (3 cases, 27.3%), and B cell lymphoma (2 cases, 18.2%). PTLDs were more prevalent in the patients with cyclosporine use (OR 13.28, 95% CI:1.29-136.31, P=0.03), acute rejection (OR 5.63, 95% CI:1.03-30.62, P=0.04), and negative serology for EBV VCA IgG (OR 19.15, 95% CI:1.99-183.98, P=0.01) by multivariate logistic regression. Three patients (27.3%) died of B cell lymphoma (2 cases) and polymorphic PTLD (1 case). The remaining patients were improved with reduction of immunosuppression and treatment with acyclovir. CONCLUSION: The incidence of PTLD was high in children. The risk factors of PTLD were negative serology for EBV VCA IgG, history of acute rejection, and cyclosporine use. Considering the poor prognosis of PTLD, effective strategies for prevention and early diagnosis for early treatment should be emphasized.
Acyclovir ; Adult ; Child ; Cyclosporine ; Diagnosis ; Early Diagnosis ; Female ; Herpesvirus 4, Human ; Humans ; Immunoglobulin G ; Immunosuppression ; Incidence ; Korea ; Liver Transplantation* ; Liver* ; Logistic Models ; Lymphoma, B-Cell ; Lymphoproliferative Disorders* ; Male ; Prevalence ; Prognosis ; Retrospective Studies ; Risk Factors ; Seoul ; Transplantation