64 results on '"Suhwan Lee"'
Search Results
2. Growth and Forage Value of Two Forage Rice Cultivars According to Harvest Time in Reclaimed Land of South Korea
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Yeongmi Jang, Khulan Sharavdorj, Priscilla Nadalin, Suhwan Lee, and Jinwoong Cho
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land reclamation ,forage value ,Mogwoo ,Mogyang ,Agriculture - Abstract
This study compares the growth of two forage rice cultivars (Oryza sativa L.), Mogwoo and Mogyang, in Midwest reclaimed land (Seongmun Tide Embankment, Korea) for two years to find the most adaptable cultivars and the appropriate harvest time. In the case of high salinity soil, it was confirmed that the influence of precipitation was relatively high on soil condition and crop growth. In Mogyang, plant height and culm length tended to decrease slightly as the precipitation increased. As for the tiller number, Mogyang was higher than Mogwoo, but the leaf area was about 1.5 to 2 times higher in Mogwoo than in Mogyang. In addition, in both cultivars, dry weight increased rapidly during the dough stage, and Mogyang was 1538 and 1815 g/m2, respectively, while Mogwoo was 2090 and 2752 g/m2, which was significantly higher. Mogyang had a CP of 4.8%, a TDN and RFV of 59.4%, 94.0, respectively, and Mogwoo had a CP of 9.7%, a TDN and RFV of 60.1%, 103.8, respectively, resulting in Mogwoo having higher values, and in particular Mogwoo was found to have better forage quality in the milk stage than in the dough stage. In addition, in terms of soil and climate conditions in Midwest reclaimed land, it was confirmed that the Mogwoo variety was the most suitable compared to Mogyang, and dry weight was higher in the dough stage than in the milk stage, but it was concluded that high forage quality could be obtained by harvesting during the milk stage.
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- 2022
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3. Effects of Harvest Time on the Yield and Forage Value of Winter Forage Crops in Reclaimed Lands of Korea
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Yeongmi Jang, Bumsik Choi, Khulan Sharavdorj, Suhwan Lee, and Jinwoong Cho
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land reclamation ,forage value ,winter cereals ,growth stage ,Agriculture (General) ,S1-972 - Abstract
This research was conducted to select the most suitable winter forage crop varieties for silage in reclaimed land located in the Midwest of Korea by investigating the soil environment, crop growth characteristics, dry weight, and forage value according to growth stage. The slightly alkalescent soil was characterized by a pH of 7.41–7.84, by an electrical conductivity (EC) of 1–2.5 dS/m, and by 440–934 mg/kg of available phosphate. Barley showed the highest chlorophyll content in the heading stage and milk stages, while oats and triticale reached the highest content in the milk and dough stage. In both years, triticale achieved the highest leaf area index (LAI), reaching 4.3–4.8. In addition, triticale showed the highest percentage of dry matter and the highest dry weight in the milk stage. Forage value was the best in the heading stage for all cereal crops; however, its quality decreased as the growth stage proceeded. This study suggests cultivating triticale, which showed high adaptability to reclaimed soil and climatic conditions, as well as good growth and dry weight when harvested between the milk and dough stages. These results indicate that triticale can be cultivated all year round in salty soil and these data can be useful to increase forage production in reclaimed soil.
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- 2022
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4. Exploring the Suitability of Rule-Based Classification to Provide Interpretability in Outcome-Based Process Predictive Monitoring
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Suhwan Lee, Marco Comuzzi, and Nahyun Kwon
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business process ,event log ,predictive monitoring ,explainability ,rule-based classification ,Industrial engineering. Management engineering ,T55.4-60.8 ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
The development of models for process outcome prediction using event logs has evolved in the literature with a clear focus on performance improvement. In this paper, we take a different perspective, focusing on obtaining interpretable predictive models for outcome prediction. We propose to use association rule-based classification, which results in inherently interpretable classification models. Although association rule mining has been used with event logs for process model approximation and anomaly detection in the past, its application to an outcome-based predictive model is novel. Moreover, we propose two ways of visualising the rules obtained to increase the interpretability of the model. First, the rules composing a model can be visualised globally. Second, given a running case on which a prediction is made, the rules influencing the prediction for that particular case can be visualised locally. The experimental results on real world event logs show that in most cases the performance of the rule-based classifier (RIPPER) is close to the one of traditional machine learning approaches. We also show the application of the global and local visualisation methods to real world event logs.
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- 2022
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5. Author Correction: A pilot study of scleral thickness in central serous chorioretinopathy using anterior segment optical coherence tomography
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Yun Ji Lee, Yeon Jeong Lee, Jae Yeon Lee, and Suhwan Lee
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Medicine ,Science - Published
- 2021
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6. A head-mounted goggle-type video-oculography system for vestibular function testing
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Youngsun Kong, Suhwan Lee, Jinseok Lee, and Yunyoung Nam
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Infrared camera ,Video-oculography ,VOG ,Videonystagmography ,VNG ,Electronics ,TK7800-8360 - Abstract
Abstract Disorders of the vestibular system possibly decrease vision, causing abnormal nystagmus and dizziness. To diagnose abnormal nystagmus, various studies have been reported including the use of rotating chair tests and videonystagmography. However, these tests are unsuitable for home use due to their high costs. Thus, a low-cost video-oculography system is necessary to obtain clinical features at home. In this paper, we present a goggle-type low-cost video-oculography system using an infrared camera and Raspberry Pi board for tracking the pupils and evaluating a vestibular system. Horizontal eye movement is derived from video data obtained from an infrared camera and infrared light-emitting diodes, and the velocity of head rotation is obtained from a gyroscope sensor. Each pupil was extracted using a morphology operation and a contour detection method. Rotatory chair tests were conducted with our developed device. To evaluate our system, gain, symmetry, and phase were measured and compared System 2000.
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- 2018
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7. Risk factors and outcomes of patients with ocular involvement of candidemia.
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Hyo-Ju Son, Min Jae Kim, Suhwan Lee, Sungim Choi, Kyung Hwa Jung, Jiwon Jung, Yong Pil Chong, Sung-Han Kim, Sang-Ho Choi, Yang Soo Kim, Jun Hee Woo, Joo Yong Lee, and Sang-Oh Lee
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Medicine ,Science - Abstract
BACKGROUND:Ocular involvement of candidemia can result in serious complications, including vision loss. This study investigated the risk factors for ocular involvement in patients with candidemia and the outcomes of treatment. METHODS:Episodes of candidemia in hospitalized adults who underwent ophthalmic examinations within 2 weeks of candidemia onset between January 2014 and May 2017 were retrospectively reviewed. Their demographic characteristics, antifungal treatments, and visual outcomes were evaluated. RESULTS:During the study period, 438 adults were diagnosed with candidemia, with 275 (62.8%) undergoing ophthalmic examinations within 2 weeks. Of these 275 patients, 59 (21.5%) had fundoscopic abnormalities suggestive of ocular involvement, including 51 with chorioretinitis and eight with Candida endophthalmitis. Eleven patients were symptomatic. Persistent candidemia (adjusted odd ratio [aOR], 2.55; 95% confidence interval [CI], 1.29-5.08; P = 0.01), neutropenia during the preceding 2 weeks (aOR, 2.92; 95% CI, 1.14-7.53; P = 0.03), and C. albicans infection (aOR, 2.15; 95% CI, 1.09-4.24; P = 0.03) were independently associated with ocular involvement. Among the 24 patients with neutropenia, 41.7% had ocular involvements at the initial examination. Ophthalmologic examination even before the neutrophil recovery was positive in one-third of neutropenic patients. Out of the 37 patients in whom ocular outcomes after 6 weeks were available, 35 patients showed favorable or stable fundoscopic findings. Two patients had decreased visual acuity despite the stable fundoscopic finding. CONCLUSION:Neutropenia within two weeks of candidemia was a risk factor for ocular involvement. More than 80 percent of patients with ocular involvements were asymptomatic, emphasizing the importance of routine ophthalmic examinations. The median 6 weeks of systemic antifungal treatment resulted in favorable outcomes in 89.2% of patients.
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- 2019
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8. 10-GSymbols/s Supply Modulated 250-GHz SiGe HBT Transmitter RF Front-End with 6.8-dBm Peak Modulated Power.
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Haidong Guo, Suprovo Ghosh, Frank Zhang, Suhwan Lee, Wooyeol Choi 0001, Shenggang Dong, and O. Kenneth
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- 2024
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9. Silicon Technology Innovation Opportunities for Applications at 0.1 to 1 THz Beyond that for Transistors.
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Kenneth K. O, Muhammad Awais, Salahuddin Tariq, Matthew Stark, Suprovo Ghosh, Farooq Muhammad Musab, Behnam Pouya, Haidong Guo, Goutham Murugesan, Suhwan Lee, Sarfraz Shariff, Walter Sosa Portillo, and Frank Zhang
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- 2023
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10. A Window of Opportunity: Active Window Tracking for Mining Work Practices.
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Iris Beerepoot, Daniël Barenholz, Stijn Beekhuis, Jens Gulden, Suhwan Lee, Xixi Lu 0001, Sietse Overbeek, Inge van de Weerd, Jan Martijn E. M. van der Werf, and Hajo A. Reijers
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- 2023
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11. Measuring the Stability of Process Outcome Predictions in Online Settings.
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Suhwan Lee, Marco Comuzzi, Xixi Lu 0001, and Hajo A. Reijers
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- 2023
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12. Federated learning for multi-omics: A performance evaluation in Parkinson's disease.
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Benjamin P. Danek, Mary B. Makarious, Anant Dadu, Dan Vitale, Paul Suhwan Lee, Andrew B. Singleton, Mike A. Nalls, Jimeng Sun 0001, and Faraz Faghri
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- 2024
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13. The Analysis of Online Event Streams: Predicting the Next Activity for Anomaly Detection.
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Suhwan Lee, Xixi Lu 0001, and Hajo A. Reijers
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- 2022
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14. Continuous Performance Evaluation for Business Process Outcome Monitoring.
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Suhwan Lee, Marco Comuzzi, and Xixi Lu 0001
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- 2021
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15. Gait analysis in patients with neurological disorders using ankle-worn accelerometers.
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Jung-Yeon Kim, Suhwan Lee, Hee Bum Lee, Byeong-Gwon Kang, Soo-Bin Im, and Yunyoung Nam
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- 2021
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16. Predicting Outpatient Process Flows to Minimise the Cost of Handling Returning Patients: A Case Study.
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Marco Comuzzi, Jonghyeon Ko, and Suhwan Lee
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- 2019
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17. Explainable Predictive Process Monitoring: A User Evaluation.
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Williams Rizzi, Marco Comuzzi, Chiara Di Francescomarino, Chiara Ghidini, Suhwan Lee, Fabrizio Maria Maggi, and Alexander Nolte
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- 2022
18. Autoencoders for improving quality of process event logs.
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Hoang Thi Cam Nguyen, Suhwan Lee, Jongchan Kim, Jonghyeon Ko, and Marco Comuzzi
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- 2019
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19. WHO HAS PRICE LEADERSHIP IN PAPRIKA TRADE BETWEEN KOREA AND JAPAN? EVIDENCE FROM THRESHOLD VECTOR AUTOREGRESSIVE MODEL APPROACH
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HANPIL MOON, JUN HO SEOK, SUHWAN LEE, and MICHAEL R. REED
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Economics and Econometrics - Abstract
Korea is not only a top paprika exporter to Japan, but also Japan is the largest Korean paprika importer. In this situation, investigating who has price leadership contributes to fill a gap in previous literature. This study examines paprika price relationships between wholesale prices in Korea, import prices in Japan and wholesale prices in Japan using monthly data from 2007 to 2017. A threshold vector autoregressive model (TVAR) and Granger causality test are used to test the price leadership between Korean exporters and Japanese importers. Moreover, forecasted prices based on TVAR show that Korean exporter’s paprika prices will be lower than Japanese importer’s price in the future. The results show that Japanese importers provide price leadership to wholesalers in Korea and Japan. Our findings suggest that paprika farmers could benefit from policies designed to address the trade situation.
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- 2022
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20. Changes in Ridge Height and Maize Growth with Various Conservation Treatments Affected by Rainfall Characteristics in Saemangeum Reclaimed Land
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Kwangseung Lee, Kangho Jung, Suhwan Lee, Jin Jung, and Banghun Kang
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- 2021
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21. Applicability of Conventionally Recommended Fertilizer Rates for Potato Cultivated in Saemangeum Reclaimed Land in the Fall Season
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Kangho Jung, Suhwan Lee, Kwangseung Lee, and Jin-Hee Ryu
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Land reclamation ,Agronomy ,engineering ,Environmental science ,Fertilizer ,engineering.material - Published
- 2021
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22. Gait analysis in patients with neurological disorders using ankle-worn accelerometers
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Byeong-Gwon Kang, Hee Bum Lee, Jung-Yeon Kim, Suhwan Lee, Yunyoung Nam, and Soo Bin Im
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020203 distributed computing ,medicine.medical_specialty ,Computer science ,02 engineering and technology ,Accelerometer ,Gait ,Theoretical Computer Science ,Physical medicine and rehabilitation ,medicine.anatomical_structure ,Gait (human) ,Hardware and Architecture ,Gait analysis ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,In patient ,Ankle ,human activities ,Software ,Information Systems ,Both ankles - Abstract
The purpose of this study is to investigate gait in patients with neurological disorders using accelerometers. Accelerometers were placed on both ankles of participants undergoing gait analysis. Data were collected during the 10-min walk test from healthy participants (n = 20) and patients with neurological deficits (n = 22) scheduled for surgery. Additional data were obtained after surgery for comparison. Both the time and frequency domain features were compared between healthy participants and patients. The interval between successive heel-strikes differed significantly, as did that between successive toe-offs. These features were correlated in healthy participants but not in patients, for whom the correlation coefficients tended to increase after surgery, indicating that the correlations can be used to monitor gait recovery and ankle-worn accelerometers were effective in collecting data for gait monitoring.
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- 2021
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23. 425-to-25-GHz CMOS-Integrated Downconverter
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Suhwan Lee, Shenggang Dong, Ibukunoluwa Momson, and K. O. Kenneth
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Physics ,business.industry ,Local oscillator ,Noise spectral density ,Transistor ,Noise figure ,Analog multiplier ,law.invention ,Intermediate frequency ,CMOS ,law ,Optoelectronics ,Radio frequency ,Electrical and Electronic Engineering ,business - Abstract
An integrated 425-GHz radio frequency (RF) to 25-GHz intermediate frequency (IF) second-order subharmonic downconverter, including an on-chip 8X local oscillator (LO) signal multiplier circuit that provides ~1 dBm at 200 GHz from an externally applied 25-GHz signal, and a 25-GHz IF amplifier, achieves a conversion gain of 6.7 dB and a noise figure of ~17 dB. The downconverter consumes 190 mW of dc power. Compared to the previously reported CMOS and SiGe HBT receivers/downconverters operating around 400 GHz and above, the downconverter achieves ~18−dB lower single side band noise figure. Finally, a passive switching mixer can have an available output noise spectral density less than kT , which can make its NF less than its conversion loss.
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- 2021
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24. Autoregulation of a trimeric transporter involves the cytoplasmic domains of both adjacent subunits
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Vanessa Leone, Richard T. Bradshaw, Caroline Koshy, Paul Suhwan Lee, Cristina Fenollar-Ferrer, Veronika Heinz, Christine Ziegler, and Lucy R. Forrest
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Membrane transporters mediate the passage of molecules across membranes and are essential for cellular function. While the transmembrane region of these proteins is responsible for substrate transport, often the cytoplasmic regions are required for modulating their activity. However, it can be difficult to obtain atomic-resolution descriptions of these autoregulatory domains by classical structural biology techniques if they lack a single, defined structure, as they may not be resolved or may be truncated or modified to facilitate crystallization. The betaine permease, BetP, a homotrimer, is a prominent and well-studied example of a membrane protein whose autoregulation depends on cytoplasmic N- and C-terminal segments. These domains sense and transduce changes in K+ concentration and in lipid bilayer properties caused by osmotic stress. However, structural data for these terminal domains is incomplete, which hinders a clear description of the molecular mechanism of autoregulation. Here we used µs-scale molecular simulations of the BetP trimer to compare reported conformations of the 45 amino-acid long C-terminal tails. The simulations provide support for the idea that the conformation derived from EM data represents a stable global orientation of the C-terminal segment under downregulating conditions. The simulations also allow a detailed molecular description of the C-terminal tail dynamics as well as its interactions with lipids, potassium ions, and the cytoplasmic surface of neighboring transporter subunits. Nevertheless, they do not provide information on the N-terminal segment, whose structure was not resolved by the structural studies. We therefore examined the possible interactions of the N-terminal tail by generating de novo models of its structure in the context of the EM-derived structure. The resultant full-length models of the BetP trimer provide a molecular framework for the arrangement of the terminal domains in the downregulated protein. In this framework, each C-terminal tail contacts the neighboring protomer in the clockwise direction (viewed from the cytoplasm), while the N-terminal tails only contact the protomer in the counterclockwise direction. This framework indicates an intricate interplay between the three protomers of BetP and, specifically, a multi-directionality that may facilitate autoregulation of betaine transport.
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- 2022
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25. The Impact of the U.S.-China Trade Dispute on the Korean Agricultural Market Using Computational General Equilibrium Model
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Suhwan Lee, Hanpil Moon, and Byung Min Soon
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General equilibrium theory ,Economics ,International economics ,China ,Agricultural market - Published
- 2020
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26. Interpreting hydrogen-deuterium exchange experiments with molecular simulations: Tutorials and applications of the HDXer ensemble reweighting software [Article v1.0]
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Paul Suhwan Lee, Richard T. Bradshaw, Fabrizio Marinelli, Kyle Kihn, Ally Smith, Patrick L. Wintrode, Daniel J. Deredge, José D. Faraldo-Gómez, and Lucy R. Forrest
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Article - Abstract
Hydrogen-deuterium exchange (HDX) is a comprehensive yet detailed probe of protein structure and dynamics and, coupled to mass spectrometry, has become a powerful tool for investigating an increasingly large array of systems. Computer simulations are often used to help rationalize experimental observations of exchange, but interpretations have frequently been limited to simple, subjective correlations between microscopic dynamical fluctuations and the observed macroscopic exchange behavior. With this in mind, we previously developed the HDX ensemble reweighting approach and associated software, HDXer, to aid the objective interpretation of HDX data using molecular simulations. HDXer has two main functions; first, to compute H-D exchange rates that describe each structure in a candidate ensemble of protein structures, for example from molecular simulations, and second, to objectively reweight the conformational populations present in a candidate ensemble to conform to experimental exchange data. In this article, we first describe the HDXer approach, theory, and implementation. We then guide users through a suite of tutorials that demonstrate the practical aspects of preparing experimental data, computing HDX levels from molecular simulations, and performing ensemble reweighting analyses. Finally we provide a practical discussion of the capabilities and limitations of the HDXer methods including recommendations for a user’s own analyses. Overall, this article is intended to provide an up-to-date, pedagogical counterpart to the software, which is freely available at https://github.com/Lucy-Forrest-Lab/HDXer.
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- 2022
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27. Insights into autoregulation of a membrane protein complex by its cytoplasmic domains
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Vanessa Leone, Richard T. Bradshaw, Caroline Koshy, Paul Suhwan Lee, Cristina Fenollar-Ferrer, Veronika Heinz, Christine Ziegler, and Lucy R. Forrest
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Biophysics - Abstract
Membrane transporters mediate the passage of molecules across membranes and are essential for cellular function. While the transmembrane region of these proteins is responsible for substrate transport, often the cytoplasmic regions are required for modulating their activity. However, it can be difficult to obtain atomic-resolution descriptions of these autoregulatory domains by classical structural biology techniques, especially if they lack a single, defined structure. The betaine permease, BetP, a homotrimer, is a prominent and well-studied example of a membrane protein whose autoregulation depends on cytoplasmic N- and C-terminal segments. These domains sense and transduce changes in K
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- 2023
- Full Text
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28. Design of drain hole for household refrigerator fan module based on experiments and CFD simulation
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Jinxing Fan, Suhwan Lee, Sunghee Kang, Junghyuk Cho, Yongbum Cho, and Eunseop Yeom
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History ,Polymers and Plastics ,Energy Engineering and Power Technology ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2023
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29. Prevalence and Risk Factors of Tamoxifen Retinopathy
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Suhwan Lee, Hyun-Ah Kim, Kyu Sang Eah, and Young Hee Yoon
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Adult ,Selective Estrogen Receptor Modulators ,medicine.medical_specialty ,MEDLINE ,Breast Neoplasms ,Drug Prescriptions ,Retina ,Young Adult ,Tamoxifen retinopathy ,Text mining ,Retinal Diseases ,Risk Factors ,Internal medicine ,Photography ,Prevalence ,medicine ,Humans ,Young adult ,Aged ,Retrospective Studies ,Aged, 80 and over ,business.industry ,Retrospective cohort study ,Middle Aged ,Tamoxifen ,Ophthalmology ,Female ,business ,Tomography, Optical Coherence - Published
- 2020
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30. An Analysis of Agricultural Trade Structure Changes and Competitiveness between China and ASEAN Countries after the 'One Belt, One Road' Initiative
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Suhwan Lee and Ji Seong Tae
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Asean countries ,business.industry ,Agriculture ,International trade ,business ,China - Published
- 2019
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31. Autoencoders for improving quality of process event logs
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Jongchan Kim, Marco Comuzzi, Jonghyeon Ko, Suhwan Lee, and Hoang Thi Cam Nguyen
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0209 industrial biotechnology ,Process modeling ,Computer science ,Business process ,General Engineering ,Process (computing) ,02 engineering and technology ,computer.software_genre ,Missing data ,Computer Science Applications ,Business process discovery ,020901 industrial engineering & automation ,Artificial Intelligence ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Anomaly detection ,Data mining ,computer ,Event (probability theory) - Abstract
Low quality of business process event logs, as determined by anomalous and missing values, is often unavoidable in practical contexts. The output of process analysis that uses event logs with missing and anomalous values is also likely to be of low quality, thus decreasing the quality of any decisions based on it. While previous work has focused on reconstructing missing events in an event log or removing anomalous traces, in this paper we focus on detecting anomalous values and reconstructing missing values at the level of attributes in event logs. We propose methods based on autoencoders, which are a class of neural networks that can reconstruct their own input and are particularly suitable to learn a model of the complex relationships among attribute values in an event log. These methods do not rely on any a-priori knowledge about the business process that generated an event log and are evaluated using real world and artificially-generated event logs. The paper also discusses a qualitative analysis of the impact of event log cleaning and reconstruction on the output of process discovery. The proposed approach shows remarkable performance regarding activity labels and timestamps in artificial event logs. The performance in the case of real world event logs, in particular timestamp anomaly detection, is lower, which may be due to high variability of attribute values in the chosen event logs. Process models discovered from reconstructed event logs are characterised by lower variability of allowed behaviour and, therefore, are more usable in practice.
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- 2019
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32. OCT Angiography Findings of Tamoxifen Retinopathy
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Suhwan Lee, Hyun-Ah Kim, and Young Hee Yoon
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medicine.medical_specialty ,Visual acuity ,genetic structures ,Fundus (eye) ,03 medical and health sciences ,0302 clinical medicine ,Breast cancer ,Ophthalmology ,Medicine ,skin and connective tissue diseases ,030304 developmental biology ,Macular telangiectasia ,0303 health sciences ,Plexus ,medicine.diagnostic_test ,business.industry ,Retrospective cohort study ,medicine.disease ,Fluorescein angiography ,eye diseases ,030221 ophthalmology & optometry ,sense organs ,medicine.symptom ,business ,Tamoxifen ,medicine.drug - Abstract
Purpose We aimed to describe the vascular changes in eyes associated with tamoxifen retinopathy using OCT angiography (OCTA) and to compare these changes with abnormalities in macular telangiectasia type 2 (MacTel 2) previously reported in the literature. Design Retrospective, observational study. Participants Seventeen eyes with tamoxifen retinopathy and 17 eyes of age-matched healthy control participants. Methods The medical records of patients who visited the ophthalmology department with a history of taking tamoxifen were reviewed. Tamoxifen retinopathy was diagnosed based on typical spectral-domain (SD) OCT findings, such as intraretinal cavitation, photoreceptor disruption, or both. Multimodal imaging, particularly focused on OCTA, was analyzed. To compare vessel density in OCTA, age-matched normal control participants also were enrolled. Main Outcome Measures Descriptive appraisal of the vascular abnormalities and objective quantification of vessel density associated with tamoxifen retinopathy. Results Among 292 patients who were screened, 26 were diagnosed with tamoxifen retinopathy. Of these, 17 eyes of 10 patients who were evaluated using OCTA were included. All patients were women, with a median patient age of 65.0 years. They were treated with tamoxifen as adjuvant endocrine therapy for breast cancer. All eyes showed intraretinal cavitation, and 8 eyes showed focal photoreceptor disruption as well, on OCT. On OCTA imaging, 14 eyes (82.4%) showed saccular capillary telangiectasia at the deep capillary plexus and 6 eyes (35.3%) showed right-angled vessels. Foveal vessel density of the superficial plexus was significantly lower in eyes with tamoxifen retinopathy than in control participants (P = 0.003). Crystalline deposits on fundus photographs (12 eyes [70.6%]) and increased autofluorescence on fundus autofluorescence (16 eyes [94.1%]) also were noted as characteristic findings of tamoxifen retinopathy. Conclusions In addition to morphologic changes of tamoxifen retinopathy in SD OCT, its vascular changes on OCTA, such as telangiectatic vascular change at the deep capillary plexus and right-angled vessels, are similar to those observed in the early stages of MacTel 2.
- Published
- 2019
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33. PRESERVATION OF THE FOVEAL FLAP IN MACULAR HOLE SURGERY
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Suhwan Lee and June-Gone Kim
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Pars plana ,medicine.medical_specialty ,Visual acuity ,genetic structures ,medicine.medical_treatment ,Vitrectomy ,03 medical and health sciences ,0302 clinical medicine ,Optical coherence tomography ,Foveal ,Medicine ,Surgical Flaps ,External limiting membrane ,Macular hole ,medicine.diagnostic_test ,business.industry ,General Medicine ,medicine.disease ,eye diseases ,Surgery ,Ophthalmology ,medicine.anatomical_structure ,030221 ophthalmology & optometry ,sense organs ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
PURPOSE To investigate the impact of preserving the foveal flap on surgical outcomes of full-thickness macular hole (MH) with foveal flaps. METHODS We retrospectively reviewed patients with Stages 2 and 3 idiopathic MH, who underwent pars plana vitrectomy by a single surgeon at Asan Medical Center from November 2011 to November 2016. In the study group, we included eyes with MH and a foveal flap on preoperative spectral domain optical coherence tomography and successfully preserved the flap during surgery. The control group included eyes with MH and an operculum in the posterior vitreous plane on preoperative optical coherence tomography. We compared the anatomical and functional surgical outcomes between these groups. RESULTS Postoperative mean best-corrected visual acuity at the last visit was 20/25 and 20/33 in the study (9 eyes) and control (23 eyes) groups, respectively. The study group showed a significantly better postoperative best-corrected visual acuity (P < 0.05). Restoration of both the external limiting membrane and ellipsoid zone, as assessed by spectral domain optical coherence tomography, was achieved in 9 (100%) and 15 (65.2%) eyes of the study and control groups, respectively. CONCLUSION Preserving the foveal flap might improve both functional and anatomical outcomes of vitrectomy for MHs with a foveal flap.
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- 2019
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34. A pilot study of scleral thickness in central serous chorioretinopathy using anterior segment optical coherence tomography
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Jae Yeon Lee, Suhwan Lee, Yeon Jeong Lee, and Yun Ji Lee
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Adult ,Male ,0301 basic medicine ,medicine.medical_specialty ,genetic structures ,Thick choroid ,Science ,Article ,03 medical and health sciences ,0302 clinical medicine ,Optical coherence tomography ,Ophthalmology ,Humans ,Medicine ,Thick sclera ,Author Correction ,Aged ,Multidisciplinary ,medicine.diagnostic_test ,Choroid ,business.industry ,Scleral diseases ,Significant difference ,Healthy subjects ,Middle Aged ,eye diseases ,Retinal diseases ,Sclera ,Serous fluid ,030104 developmental biology ,medicine.anatomical_structure ,Central Serous Chorioretinopathy ,Vision disorders ,Case-Control Studies ,030221 ophthalmology & optometry ,Female ,Enhanced depth imaging ,sense organs ,business ,Tomography, Optical Coherence - Abstract
The aim of this study is to compare the scleral thickness of central serous chorioretinopathy (CSC) eyes with controls using anterior segment optical coherence tomography (AS OCT). This prospective case control study included 15 patients (15 eyes) with CSC and 15 age and gender matched healthy subjects. All subjects underwent spectral domain OCT with enhanced depth imaging and swept source AS OCT of temporal sclera. We investigated difference in scleral thickness between the two groups and relationship between choroidal and scleral thickness. Among the 15 eyes in the study group, 1 eye had acute CSC, 4 had recurrent CSC, 7 had inactive CSC, and 3 had chronic CSC. There was no significant difference in terms of age, gender, axial length and spherical equivalent between the two groups. The choroidal and scleral thickness of the study group were significantly greater than those of the control group (P P = 0.034). Choroidal thickness was positively correlated with scleral thickness (P = 0.031). A thick sclera along with a thick choroid were demonstrated in CSC eyes using AS OCT. Scleral characteristics might be involved in the pathogenesis of CSC by affecting outflow resistance of venous drainage in choroidal circulation.
- Published
- 2021
35. Author Correction: A pilot study of scleral thickness in central serous chorioretinopathy using anterior segment optical coherence tomography
- Author
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Jae Yeon Lee, Suhwan Lee, Yeon Jeong Lee, and Yun Ji Lee
- Subjects
medicine.medical_specialty ,Multidisciplinary ,medicine.diagnostic_test ,business.industry ,Science ,Serous fluid ,Text mining ,Optical coherence tomography ,Ophthalmology ,medicine ,Medicine ,business ,Geology - Published
- 2021
36. Systemic factors and early treatment response to intravitreal injection for diabetic macular edema; the role of renal function
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Dong Yoon Kim, Hwanho Lee, Suhwan Lee, Ju Byung Chae, Eoi Jong Seo, Hye Seong Hwang, and Jin Young Kim
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Male ,Vascular Endothelial Growth Factor A ,Treatment response ,medicine.medical_specialty ,genetic structures ,Visual Acuity ,Urology ,Renal function ,Angiogenesis Inhibitors ,030209 endocrinology & metabolism ,Kidney ,Dexamethasone ,Macular Edema ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Diabetes mellitus ,medicine ,Humans ,Glucocorticoids ,Blood urea nitrogen ,Creatinine ,Diabetic Retinopathy ,business.industry ,Retinal ,General Medicine ,Middle Aged ,medicine.disease ,eye diseases ,Bevacizumab ,Ophthalmology ,chemistry ,Intravitreal Injections ,030221 ophthalmology & optometry ,Female ,Implant ,business ,Tomography, Optical Coherence ,Glomerular Filtration Rate ,medicine.drug - Abstract
PURPOSE To investigate the effect of systemic factors on early treatment response to intravitreal bevacizumab injection (IVBI) and intravitreal dexamethasone implant (IVDI) in patients with diabetic macular edema (DME). METHODS We reviewed the medical records of 117 treatment naive DME patients who underwent IVBI. We divided the patients according to their IVBI response. An IVDI was performed in patients with poor response to IVBIs. We investigated the various systemic factors of diabetic patients and examined the relationship between systemic factors and the treatment response to IVBI and IVDI. RESULTS In a total of 117 treatment naive DME eyes, 61 eyes (52.14%) were classified as IVBI responders. An IVDI was performed in 23 of 56 eyes with poor response to IVBI, and 17 eyes (73.91%) had a good response. Among various systemic factors of patients with diabetes, renal function (blood urea nitrogen, creatinine, and estimated glomerular filtration rate) showed a significant negative correlation with central subfield retinal thickness improvement after treatment (P < 0.05). However, there was no difference in HbA1C levels regarding the treatment response to IVBI and IVDI. CONCLUSION Renal function was significantly worse in patients with a poor response to IVBI and IVDI. Renal function could be used as a possible predictor for treatment response in certain patients with DME. Furthermore, for patients with DME with poor responses to anti-vascular endothelial growth factor or steroid treatments, assessment of renal function could help explain the poor treatment response.
- Published
- 2020
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37. Long-Term Visual/Anatomic Outcome in Patients with Fovea-Involving Fibrovascular Pigment Epithelium Detachment Presenting Choroidal Neovascularization on Optical Coherence Tomography Angiography
- Author
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Hwanho Lee, Kyung-Tae Kim, Jin Young Kim, Suhwan Lee, Ju Byung Chae, and Dong Yoon Kim
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fibrovascular pigment epithelial detachment ,medicine.medical_specialty ,Visual acuity ,genetic structures ,exudative age-related macular degeneration ,lcsh:Medicine ,choroidal neovascularization ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Ophthalmology ,medicine ,In patient ,anti-vascular endothelial growth factor ,Retina ,business.industry ,lcsh:R ,Retinal ,General Medicine ,Optical coherence tomography angiography ,Macular degeneration ,medicine.disease ,Epithelium ,eye diseases ,medicine.anatomical_structure ,Choroidal neovascularization ,chemistry ,030221 ophthalmology & optometry ,sense organs ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
Background: To evaluate long-term visual/anatomic outcome after anti-vascular endothelial growth factor (anti-VEGF) therapy in patients with fovea-involving fibrovascular pigment epithelium detachment (PED) presenting with choroidal neovascularization (CNV) on optical coherence tomography angiography (OCTA). Methods: Patients with fibrovascular PED or subretinal CNV confirmed by OCTA who were treated by a relaxed treat-and-extend regimen for 2 years were retrospectively reviewed. The best-corrected visual acuity (BCVA) and central subfield retinal thickness (CST) before and after anti-VEGF injection were analyzed. Furthermore, changes in photoreceptor layer (PRL) thickness and outer retinal bands in the fovea after injection were evaluated. Results: A total of 31 eyes with fibrovascular PED and 24 eyes with subretinal CNV were included. Following a relaxed treat-and-extend regimen with anti-VEGF agents, BCVA and CST were improved, and the PRL thickness was decreased significantly. There were no differences in BCVA, CST, changes in PRL thickness, or the status of outer retinal bands between the groups. However, the difference in the amount of decrease in PRL thickness between the two groups was increased at 2 years, and the slope tended to be steeper in the subretinal CNV group. Conclusions: Exudative age-related macular degeneration (AMD) with fibrovascular PED or subretinal CNV showed good visual/anatomic outcomes after anti-VEGF treatment, regardless of the CNV type. By 2 years, fibrovascular PED did not have an additional protective effect on the outer retina, compared with subretinal CNV over 2 years. Further follow-up study might be needed to conclude that fibrovascular PED has a protective effect on the surrounding photoreceptor area.
- Published
- 2020
38. Reply
- Author
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Suhwan Lee and June-Gone Kim
- Subjects
Ophthalmology ,Fovea Centralis ,Humans ,General Medicine ,Retinal Perforations - Published
- 2020
39. An International Comparison of Baseline Characteristics of Patients Undergoing Initiation of Anti-VEGF Therapy for DME
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Suhwan Lee, Chandruganesh Rasendran, Ram Kailash Gurjar, Diogo Neves, Siraj Haq, Fabiana S Queiroga, Jay Chhablani, Rishi P Singh, Sundaram Natarajan, Chinmay Nakhwa, Jose Romero, Arturo Alezzandrini, Jorge Rocha, Michael Han, Ramon P Martins, Lihteh Wu, Young Hee Yoon, Felipe F Conti, and Waseem Ansari
- Subjects
Male ,medicine.medical_specialty ,Visual acuity ,genetic structures ,Cross-sectional study ,Visual Acuity ,Angiogenesis Inhibitors ,Fundus (eye) ,Macular Edema ,Retina ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,Ranibizumab ,Edema ,Ophthalmology ,Diabetes mellitus ,Epidemiology ,medicine ,Humans ,Aged ,Diabetic Retinopathy ,business.industry ,Vascular disease ,Diabetic retinopathy ,Middle Aged ,medicine.disease ,eye diseases ,Cross-Sectional Studies ,Intravitreal Injections ,030221 ophthalmology & optometry ,Female ,medicine.symptom ,business - Abstract
BACKGROUND AND OBJECTIVE: Diabetic macular edema (DME) is a leading cause of vision loss worldwide. The object of this study is to compare global differences of baseline characteristics of patients undergoing initiation of anti-vascular endothelial growth factor (VEGF) therapy for DME. PATIENTS AND METHODS: This multicenter, cross-sectional study included diabetic patients with foveal-involving retinal edema secondary to DME as documented by fundus exam and optical coherence tomography who were undergoing initiation of intravitreal anti-VEGF drugs. Variables were collected to find possible risk factors and to create an epidemiological profile of DME patients undergoing initiation of anti-VEGF agents. RESULTS: Nine hundred two patients were selected. Mean age was 62.4 (±11) years, 49.7% were Caucasians, 57.6% were male, and 96% had type two diabetes with an average disease duration of 181.7 months ± 113 months. Of the patients included, 74.7% suffered from hypertension, 26.6% from cardiovascular disease, 12.1% from cerebrovascular disease, 12.8% from peripheral vascular disease, and 12.8% from renal insufficiency. Best-corrected visual acuity (BCVA) was 65 (±20) Early Treatment Diabetic Retinopathy Study letters, central subfield thickness was 364 (±162) μm, cube volume 11.1 ± 3.1 mm 3 , cube average thickness 328.8 μm ± 61 μm, and 63.9% had nonproliferative diabetic retinopathy. Comparison between U.S. versus international patients, and patients with BCVA 70 letters or less versus more than 70 letters were performed, significant differences were acknowledged, and risk factors were recognized. CONCLUSION: There were key differences in the epidemiologic profile between patients presenting with DME in the U.S. and internationally. [ Ophthalmic Surg Lasers Imaging Retina . 2019;50:e300–e310.]
- Published
- 2019
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40. The Effect of Tumor Necrosis Factor-Alpha Inhibitors on Uveitis in Patients with Ankylosing Spondylitis
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Joo Yong Lee, Suhwan Lee, and Yu Jeong Park
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Adult ,Male ,medicine.medical_specialty ,Tumor Necrosis Factor-Alpha ,Ankylosing Spondylitis ,Kaplan-Meier Estimate ,Gastroenterology ,Etanercept ,Uveitis ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Immunology, Allergic Disorders & Rheumatology ,Recurrence ,Internal medicine ,medicine ,Adalimumab ,Humans ,Spondylitis, Ankylosing ,030212 general & internal medicine ,Anterior Uveitis ,Aged ,Retrospective Studies ,Ankylosing spondylitis ,business.industry ,Incidence (epidemiology) ,Antibodies, Monoclonal ,General Medicine ,Middle Aged ,medicine.disease ,Golimumab ,Infliximab ,Tumor necrosis factor alpha ,Original Article ,Female ,business ,medicine.drug - Abstract
Background Tumor necrosis factor-alpha (TNF-α) inhibitors (TNFis), which are the main treatment for ankylosing spondylitis (AS), have been reported not only to reduce the incidence of anterior uveitis (AU) but also to induce it, and these effects differ among the various types of TNFis in clinical use. The present study investigated the effect of TNFis on uveitis by analyzing the long-term clinical course of AU in AS patients treated with TNFi therapy. Methods Patients treated with at least one TNFi between January 2007 and July 2017 were reviewed, and 54 patients with at least one episode of AU were included in this study. The TNFis included anti-TNF-α antibodies (adalimumab, infliximab, and golimumab), and a soluble TNF receptor molecule (etanercept). The effect of prevention of AU, the likelihood of new-onset uveitis after the initiation of TNFi therapy, and the effects of drug switching and dose escalation were assessed. Results The first uveitis flare was observed before TNFi therapy in 39 patients and after TNFi therapy in 15 patients. Anti-TNF-α antibodies were more efficacious in decreasing the recurrence of AU than etanercept. Among patients in which uveitis first occurred after beginning TNFi therapy, patients on etanercept tended to first develop AU less than 1 year after starting the drug, and their AS tended to be well-controlled at the time of uveitis flares. Patients with a uveitis flare before their medication was switched did not recur afterwards, and five of eight patients showed no relapse after dose escalation. Conclusion TNFis have various effects on AU. TNFis, particularly anti-TNF-α antibodies, should be considered in patients with AS and frequent AU relapse. Additionally, clinicians should consider whether AU is due to an absence of a therapeutic response of AS to TNFi treatment or to TNFi treatment itself, and appropriate treatment changes should be made accordingly., Graphical Abstract
- Published
- 2019
41. Predicting Outpatient Process Flows to Minimise the Cost of Handling Returning Patients: A Case Study
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Jonghyeon Ko, Suhwan Lee, and Marco Comuzzi
- Subjects
Initial visit ,Overhead (business) ,Computer science ,Process (engineering) ,Business process ,Intervention (counseling) ,Outpatient clinic ,Operations management ,health care economics and organizations - Abstract
We describe an application of process predictive monitoring at an outpatient clinic in a large hospital. A model is created to predict which patients will wrongly refer to the outpatient clinic, instead of directly to other departments, when returning to get treatment after an initial visit. Four variables are identified to minimise the cost of handling these patients: the cost of giving appropriate guidance to them, the cost of handling patients taking a non-compliant flow by wrongly referring to the outpatient clinic, and the false positive/negative rates of the predictive model adopted. The latter determine the situations in which patients have not received guidance when they should have had or have been guided even though not necessary, respectively. Using these variables, a cost model is built to identify which combinations of process intervention/redesign options and predictive models are likely to minimise the cost overhead of handling the returning patients.
- Published
- 2019
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42. Risk factors and outcomes of patients with ocular involvement of candidemia
- Author
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Joo Yong Lee, Kyung Hwa Jung, Jun Hee Woo, Min Jae Kim, Jiwon Jung, Hyo-Ju Son, Sungim Choi, Sung-Han Kim, Sang-Ho Choi, Yong Pil Chong, Yang Soo Kim, Suhwan Lee, and Sang-Oh Lee
- Subjects
Male ,0301 basic medicine ,Antifungal Agents ,Epidemiology ,Neutrophils ,Yeast and Fungal Models ,Pathology and Laboratory Medicine ,White Blood Cells ,0302 clinical medicine ,Risk Factors ,Animal Cells ,Medicine and Health Sciences ,Candida ,Fungal Pathogens ,Multidisciplinary ,Antimicrobials ,Eukaryota ,Drugs ,Middle Aged ,Prognosis ,Treatment Outcome ,Experimental Organism Systems ,Medical Microbiology ,Decreased Visual Acuity ,Medicine ,Female ,Pathogens ,Anatomy ,Cellular Types ,medicine.symptom ,Eye Infections, Fungal ,Research Article ,medicine.medical_specialty ,Neutropenia ,Fundus Oculi ,Immune Cells ,Science ,Immunology ,030106 microbiology ,Mycology ,Research and Analysis Methods ,Microbiology ,Asymptomatic ,03 medical and health sciences ,Signs and Symptoms ,Ocular System ,Diagnostic Medicine ,Microbial Control ,Internal medicine ,medicine ,Humans ,Candida Albicans ,Risk factor ,Microbial Pathogens ,Aged ,Retrospective Studies ,Pharmacology ,Antifungals ,Blood Cells ,business.industry ,Organisms ,Fungi ,Chorioretinitis ,Candidemia ,Biology and Life Sciences ,Retrospective cohort study ,Cell Biology ,Eye infection ,medicine.disease ,Yeast ,Confidence interval ,Ophthalmoscopy ,Ophthalmology ,Medical Risk Factors ,Animal Studies ,Lesions ,030221 ophthalmology & optometry ,Eyes ,business ,Head - Abstract
Background Ocular involvement of candidemia can result in serious complications, including vision loss. This study investigated the risk factors for ocular involvement in patients with candidemia and the outcomes of treatment. Methods Episodes of candidemia in hospitalized adults who underwent ophthalmic examinations within 2 weeks of candidemia onset between January 2014 and May 2017 were retrospectively reviewed. Their demographic characteristics, antifungal treatments, and visual outcomes were evaluated. Results During the study period, 438 adults were diagnosed with candidemia, with 275 (62.8%) undergoing ophthalmic examinations within 2 weeks. Of these 275 patients, 59 (21.5%) had fundoscopic abnormalities suggestive of ocular involvement, including 51 with chorioretinitis and eight with Candida endophthalmitis. Eleven patients were symptomatic. Persistent candidemia (adjusted odd ratio [aOR], 2.55; 95% confidence interval [CI], 1.29–5.08; P = 0.01), neutropenia during the preceding 2 weeks (aOR, 2.92; 95% CI, 1.14–7.53; P = 0.03), and C. albicans infection (aOR, 2.15; 95% CI, 1.09–4.24; P = 0.03) were independently associated with ocular involvement. Among the 24 patients with neutropenia, 41.7% had ocular involvements at the initial examination. Ophthalmologic examination even before the neutrophil recovery was positive in one-third of neutropenic patients. Out of the 37 patients in whom ocular outcomes after 6 weeks were available, 35 patients showed favorable or stable fundoscopic findings. Two patients had decreased visual acuity despite the stable fundoscopic finding. Conclusion Neutropenia within two weeks of candidemia was a risk factor for ocular involvement. More than 80 percent of patients with ocular involvements were asymptomatic, emphasizing the importance of routine ophthalmic examinations. The median 6 weeks of systemic antifungal treatment resulted in favorable outcomes in 89.2% of patients.
- Published
- 2019
43. OCT Angiography Findings of Tamoxifen Retinopathy: Similarity with Macular Telangiectasia Type 2
- Author
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Suhwan, Lee, Hyun-Ah, Kim, and Young Hee, Yoon
- Subjects
Selective Estrogen Receptor Modulators ,Fundus Oculi ,Visual Acuity ,Breast Neoplasms ,Middle Aged ,Multimodal Imaging ,Tamoxifen ,Retinal Diseases ,Humans ,Retinal Telangiectasis ,Female ,Fluorescein Angiography ,Tomography, Optical Coherence ,Aged ,Retrospective Studies - Abstract
We aimed to describe the vascular changes in eyes associated with tamoxifen retinopathy using OCT angiography (OCTA) and to compare these changes with abnormalities in macular telangiectasia type 2 (MacTel 2) previously reported in the literature.Retrospective, observational study.Seventeen eyes with tamoxifen retinopathy and 17 eyes of age-matched healthy control participants.The medical records of patients who visited the ophthalmology department with a history of taking tamoxifen were reviewed. Tamoxifen retinopathy was diagnosed based on typical spectral-domain (SD) OCT findings, such as intraretinal cavitation, photoreceptor disruption, or both. Multimodal imaging, particularly focused on OCTA, was analyzed. To compare vessel density in OCTA, age-matched normal control participants also were enrolled.Descriptive appraisal of the vascular abnormalities and objective quantification of vessel density associated with tamoxifen retinopathy.Among 292 patients who were screened, 26 were diagnosed with tamoxifen retinopathy. Of these, 17 eyes of 10 patients who were evaluated using OCTA were included. All patients were women, with a median patient age of 65.0 years. They were treated with tamoxifen as adjuvant endocrine therapy for breast cancer. All eyes showed intraretinal cavitation, and 8 eyes showed focal photoreceptor disruption as well, on OCT. On OCTA imaging, 14 eyes (82.4%) showed saccular capillary telangiectasia at the deep capillary plexus and 6 eyes (35.3%) showed right-angled vessels. Foveal vessel density of the superficial plexus was significantly lower in eyes with tamoxifen retinopathy than in control participants (P = 0.003). Crystalline deposits on fundus photographs (12 eyes [70.6%]) and increased autofluorescence on fundus autofluorescence (16 eyes [94.1%]) also were noted as characteristic findings of tamoxifen retinopathy.In addition to morphologic changes of tamoxifen retinopathy in SD OCT, its vascular changes on OCTA, such as telangiectatic vascular change at the deep capillary plexus and right-angled vessels, are similar to those observed in the early stages of MacTel 2.
- Published
- 2018
44. Correlation between Visual Function and Structural Characteristics of the Macula in Advanced Retinitis Pigmentosa
- Author
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Young Hee Yoon, Gisung Son, Yoon Jeon Kim, Joo Yong Lee, June-Gone Kim, and Suhwan Lee
- Subjects
Adult ,Male ,medicine.medical_specialty ,Visual acuity ,genetic structures ,Visual Acuity ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Optical coherence tomography ,Ophthalmology ,Bayesian multivariate linear regression ,Retinitis pigmentosa ,medicine ,Humans ,Macula Lutea ,0101 mathematics ,Retrospective Studies ,Retina ,medicine.diagnostic_test ,business.industry ,Choroid ,010102 general mathematics ,Retinal ,General Medicine ,Organ Size ,Middle Aged ,medicine.disease ,eye diseases ,Sensory Systems ,Visual field ,medicine.anatomical_structure ,Cross-Sectional Studies ,chemistry ,030221 ophthalmology & optometry ,Visual Field Tests ,Female ,sense organs ,medicine.symptom ,Visual Fields ,business ,Retinitis Pigmentosa ,Tomography, Optical Coherence - Abstract
We aimed to correlate the visual function and structural characteristics of the retina and choroid in advanced retinitis pigmentosa (RP) patients. A cross-sectional, retrospective review was conducted of medical records of 149 RP patients who reported visual field constriction on a central 30-2 Humphrey visual field chart. Using spectral domain-optical coherence tomography, central foveal thickness (CFT), ellipsoid zone (EZ) length, macular volume (MV), and submacular choroidal thickness (SMChT) were measured. A control cohort (68 eyes of 68 patients) was included for comparing the macular structure. Quantitative correlations between visual function indices [visual field index (VFI) and best-corrected visual acuity (BCVA)] and structural indices (CFT, EZ length, and SMChT) were evaluated. Mean age was 46.3 ± 15.5 years; mean illness duration was 60.7 ± 60.0 months. SMChT was thinner than that in normal controls. Per Pearson’s correlation, BCVA and VFI exhibited a progressive worsening related to age and disease duration. In multivariate linear regression, BCVA and VFI were significantly correlated with CFT, EZ length, and MV at the central 1-mm area. Among RP patients with visual field constriction within 30°, VFI and BCVA closely correlate with the degree of retinal structural change, including the CFT, EZ length, and MV. SMChT uniformly decreased in this study population and exhibited no significant correlation with BCVA or VFI degree.
- Published
- 2018
45. Relationship Between Neutralizing Antibodies Against Adeno-Associated Virus in the Vitreous and Serum: Effects on Retinal Gene Therapy
- Author
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Joo Yong Lee, Suhwan Lee, Im Kyeung Kang, Heuiran Lee, Ji Hyun Kim, Keerang Park, Heesoon Chang, and Bok Kyoung Jung
- Subjects
medicine.medical_specialty ,genetic structures ,medicine.medical_treatment ,Biomedical Engineering ,Blood–retinal barrier ,Vitrectomy ,medicine.disease_cause ,chemistry.chemical_compound ,Ophthalmology ,medicine ,Adeno-associated virus ,blood–retinal barrier ,medicine.diagnostic_test ,biology ,business.industry ,neutralizing antibody ,Retinal ,Articles ,Fluorescein angiography ,medicine.disease ,vitreous humor ,gene therapy ,eye diseases ,medicine.anatomical_structure ,chemistry ,adeno-associated virus serotype ,Vitreous hemorrhage ,biology.protein ,sense organs ,Epiretinal membrane ,Antibody ,business ,serum - Abstract
Purpose We determine the prevalence of neutralizing antibodies (NAbs) to adeno-associated virus (AAV) in the vitreous humor and serum of patients with vitreoretinal diseases and investigate the relationship between NAb titers in the vitreous humor and serum. Methods We analyzed NAbs to AAV serotypes 2, 5, 8, and 9 via in vitro neutralization in the vitreous humor and serum from 32 patients requiring vitrectomy for vitreoretinal diseases. The blood-retinal barrier (BRB) was evaluated for integrity based on preoperative examinations, with vitreous hemorrhage (VH) on funduscopy or dye leakage on fluorescein angiography observed indicating disruption. Results NAb levels were much lower in the vitreous humor than in the serum regardless of serotype. Patients with VH had higher levels of NAbs in the vitreous humor than those without VH. The NAb ratio (ratio between NAb titers in the serum and vitreous humor) was much lower in patients with epiretinal membrane with than in those without leakage. A significantly lower NAb ratio was noticed in patients with than in those without BRB disruptions. Conclusions The NAb ratio between levels in serum and vitreous humor varies according to the condition of the BRB. Therefore, in addition to measuring the serum NAb level, physicians should examine BRB integrity when planning retinal gene therapy. Translational relevance This study provides substantial basis for retinal gene therapy using AAVs and how maintenance of BRB integrity in target diseases should be considered.
- Published
- 2019
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46. Surgical reduction of ocular pigmentation in patients with oculodermal melanocytosis
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Myoung Joon Kim, Hungwon Tchah, Jooeun Lee, Jung Taeck Hong, Suhwan Lee, and Jae Yong Kim
- Subjects
Adult ,Male ,Uveal Neoplasms ,medicine.medical_specialty ,Adolescent ,Ophthalmologic Surgical Procedures ,Eyelid Neoplasms ,Nevus of Ota ,Surgical Flaps ,Postoperative Complications ,medicine ,Humans ,In patient ,Child ,Intraocular Pressure ,Retrospective Studies ,business.industry ,Middle Aged ,eye diseases ,Surgery ,Scleral Diseases ,Ophthalmology ,Treatment Outcome ,Surgical reduction ,Patient Satisfaction ,Female ,sense organs ,business - Abstract
To show the outcomes of surgical reduction of ocular pigmentation in patients with oculodermal melanocytosis.Surgical reduction of ocular pigmentation was performed in 49 patients with oculodermal melanocytosis at the Asan Medical Center, Seoul, Republic of Korea, between January 2005 and January 2009.In all patients, ocular pigmentation was cosmetically reduced, and most patients were satisfied with the results of surgery. Preoperative and postoperative visual acuities, intraocular pressure (IOP), keratometry, and refractive outcomes did not differ significantly. During the follow-ups, 14 patients showed transient IOP elevation and 4 patients showed conjunctival neovascularization.Surgical reduction of oculodermal melanocytosis seemed to be cosmetically satisfactory and did not cause significant changes in visual acuity, refraction, or keratometry, although 28.6% (14 of 49) of patients showed transient IOP elevation.
- Published
- 2012
47. Changes in the clinical features and prognostic factors of endogenous endophthalmitis: fifteen years of clinical experience in Korea
- Author
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Jong-uk Hwang, Suhwan Lee, Soo Geun Joe, Joo-Yong Lee, Taewoong Um, June-Gone Kim, and Young Hee Yoon
- Subjects
Adult ,Liver Cirrhosis ,Male ,Pediatrics ,medicine.medical_specialty ,Visual acuity ,Cirrhosis ,Adolescent ,medicine.medical_treatment ,Liver Abscess ,Visual Acuity ,Vitrectomy ,Eye Infections, Bacterial ,Young Adult ,Endophthalmitis ,Risk Factors ,Republic of Korea ,medicine ,Diabetes Mellitus ,Humans ,Young adult ,Aged ,Retrospective Studies ,Aged, 80 and over ,Bacteria ,business.industry ,Fungi ,Retrospective cohort study ,General Medicine ,Eye infection ,Middle Aged ,medicine.disease ,Prognosis ,Anti-Bacterial Agents ,Ophthalmology ,Female ,medicine.symptom ,business ,Eye Infections, Fungal ,Eye Evisceration ,Liver abscess - Abstract
PURPOSE To identify changes in the clinical features, management, and prognostic factors of endogenous endophthalmitis in Korea from 1996 through 2010. METHODS We conducted a retrospective review of medical records of patients diagnosed with endogenous endophthalmitis from January 1996 to December 2010, which was divided into 3 periods: 1996 to 2000, 2001 to 2005, and 2006 to 2010. Variables included age, source of infection, systemic conditions, initial and final visual acuities, causative organisms, and treatment. RESULTS Endophthalmitis was identified in 80 patients (97 eyes). Diabetes (42.5%) and liver cirrhosis (20%) were the common systemic problems in these patients. Liver abscess (25%) was the most common infection focus of the endophthalmitis. Klebsiella pneumoniae (48.4%) was the common causative agent, although more recently, endophthalmitis caused by gram-positive cocci has increased in frequency. The use of vitrectomy as an initial treatment has increased during the past 5 years. Good initial visual acuity greater than counting fingers (P < 0.001), early vitrectomy in patients with initially good visual presentation (P = 0.035), and gram-positive cocci (P = 0.033) as a causative agent were significantly related to a successful visual outcome. CONCLUSION Although the prognosis of endogenous endophthalmitis is generally poor in most patients, some eyes can have relatively good visual outcomes if treated appropriately and early enough.
- Published
- 2011
48. Relationship between visual field sensitivity and macular ganglion cell complex thickness as measured by spectral-domain optical coherence tomography
- Author
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Jung Hwa Na, Michael S. Kook, Jaewan Choi, Sung-Cheol Yun, Suhwan Lee, Sung Yong Kang, Jung Woo Cho, Youngrok Lee, and Kyung Rim Sung
- Subjects
Male ,Retinal Ganglion Cells ,medicine.medical_specialty ,Optic Disk ,Optic disk ,Nerve fiber layer ,Vision Disorders ,Glaucoma ,Tonometry, Ocular ,Nerve Fibers ,Optical coherence tomography ,Ophthalmology ,Linear regression ,Optic Nerve Diseases ,medicine ,Humans ,Macula Lutea ,Prospective Studies ,Intraocular Pressure ,Mathematics ,Decibel ,medicine.diagnostic_test ,Middle Aged ,medicine.disease ,Visual field ,medicine.anatomical_structure ,Cross-Sectional Studies ,Visual Field Tests ,Female ,Visual Fields ,Nonlinear regression ,Glaucoma, Open-Angle ,Tomography, Optical Coherence - Abstract
PURPOSE: To evaluate the strength and pattern of the relationship between visual field (VF) mean sensitivity (MS), assessed by standard automated perimetry (SAP), and macular ganglion cell complex thickness (GCCT), measured with spectral-domain optical coherence tomography (SD-OCT). METHODS: Ninety-seven glaucoma patients were enrolled. GCCT, determined by ganglion cell complex (GCC) scanning, and two peripapillary retinal nerve fiber layer thickness (pRNFLT) measurements, using the NHM4 (RNFL1) and RNFL 3.45 (RNFL2) modes, were recorded. MS was recorded on the decibel (dB) and 1/L scales. The relationship between function (MS) and structure (GCC, pRNFLT) was sought. RESULTS: The association of MS (in decibels) with GCC global (r = 0.445) and sectoral (superior, r = 0.528; inferior, r = 0.370) thicknesses was not significantly different from that of MS to global (RNFL1, r = 0.505; RNFL2, r = 0.498) and sectoral (RNFL 1 superior, r = 0.559; inferior, r = 0.440; RNFL 2 superior, r = 0.535; inferior, r = 0.443) pRNFLT, on linear regression analysis. The relationship pattern was curvilinear on the dB scale against GCCT and RNFLT. Logarithmic regression of MS (using both the dB and 1/L scales) against GCCT and RNFLT was better than linear regression in describing the pattern of association. CONCLUSIONS: GCCT, determined by SD-OCT, showed correlation to MS of a strength similar to that demonstrated between MS and pRNFLT.
- Published
- 2010
49. Spectral-domain optical coherence tomography and scanning laser polarimetry in glaucoma diagnosis
- Author
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Jung Woo Cho, Michael S. Kook, Sung Yong Kang, Kyung Rim Sung, Suhwan Lee, and Mi Hyun Cheon
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Male ,Retinal Ganglion Cells ,Materials science ,genetic structures ,Optic Disk ,Nerve fiber layer ,Scanning laser polarimetry ,Glaucoma ,Spectral domain ,Sensitivity and Specificity ,chemistry.chemical_compound ,Tonometry, Ocular ,Optics ,Nerve Fibers ,Optical coherence tomography ,Optic Nerve Diseases ,medicine ,Humans ,medicine.diagnostic_test ,business.industry ,Retinal ,General Medicine ,Middle Aged ,medicine.disease ,eye diseases ,Ophthalmology ,medicine.anatomical_structure ,chemistry ,ROC Curve ,Scanning Laser Polarimetry ,Area Under Curve ,Cirrus ,Female ,sense organs ,Tomography ,business ,Tomography, Optical Coherence - Abstract
To evaluate glaucoma diagnostic capability of the retinal nerve fiber layer (RNFL) imaging by spectral-domain optical coherence tomography (Cirrus OCT) and scanning laser polarimetry (GDx VCC).We imaged 88 glaucomatous and 77 healthy eyes using both devices. Areas under the receiver-operating characteristic curves (area under the curves, AUCs) and sensitivities at fixed specificities of average, superior, and inferior RNFL thickness were compared. Likelihood ratios (LRs) and diagnostic agreement based on normative classifications yielded by both devices were determined.The best performing parameter was the nerve fiber indicator (NFI) in GDx VCC and inferior RNFL thickness in Cirrus OCT (AUC = 0.912, 0.961, P = 0.045). The AUCs of the Cirrus OCT were significantly higher than those of GDx VCC in all parameters. Most of the parameters in Cirrus OCT were more sensitive than GDx VCC in the detection of glaucoma at fixed specificity values. Cirrus OCT had an infinite LR with abnormal classification results in both average and superior RNFL thickness. There was good agreement between the two instruments with respect to abnormal classifications (kappa, 0.611-0.766)Both Cirrus OCT and GDx VCC RNFL measurements showed good glaucoma diagnostic capabilities. Cirrus OCT showed higher sensitivities than GDx VCC.
- Published
- 2010
50. Characteristics of Visual Field Progression in Medically Treated Normal-Tension Glaucoma Patients with Unstable Ocular Perfusion Pressure
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Sung-Cheol Yun, Kyung Rim Sung, Jaewan Choi, Jung Woo Cho, Youngrok Lee, Jung Hwa Na, Suhwan Lee, and Michael S. Kook
- Subjects
Male ,Intraocular pressure ,Mean arterial pressure ,medicine.medical_specialty ,genetic structures ,Gonioscopy ,Vision Disorders ,Glaucoma ,Blood Pressure ,Tonometry, Ocular ,Normal tension glaucoma ,Ophthalmology ,medicine ,Humans ,Low Tension Glaucoma ,Antihypertensive Agents ,Intraocular Pressure ,Proportional Hazards Models ,Retrospective Studies ,medicine.diagnostic_test ,Proportional hazards model ,business.industry ,Hazard ratio ,Middle Aged ,medicine.disease ,eye diseases ,Drug Combinations ,Blood pressure ,Disease Progression ,Female ,Visual Fields ,business ,Follow-Up Studies - Abstract
Purpose To investigate the characteristics of visual field (VF) progression in medically treated normal-tension glaucoma (NTG) patients (Koreans) with unstable ocular perfusion pressure (OPP). Methods One hundred one eyes of 101 NTG patients followed up for more than 4 years (mean follow-up, 6.2 years ± 12.1 months) were included. Modified Anderson criteria (MC) and linear regression analysis (LA) of VF mean deviation (MD) within the central 10° and 10° to 24° area were assessed for determining VF progression in groups with lowest (LMF) and highest (HMF) 24-hour mean OPP [MOPP = 2/3;(mean arterial pressure - IOP)] fluctuation. Kaplan-Meier analyses were used to compare the elapsed time of confirmed VF progression in the two groups. Hazard ratios (HRs) for the association between clinical risk factors including 24-hour MOPP and central VF progression were obtained by using Cox proportional hazards models. Results Three of 33 eyes in the LMF progressed, whereas 12 of 34 eyes in the HMF progressed within the central 10° according to the MC; the between-group difference was significant (P = 0.010). By LA within the central 10°, two eyes from the LMF and nine from the HMF groups showed progression (P = 0.025). The HMF showed a greater cumulative probability of central VF progression than the LMF, by both LA and MC (Kaplan-Meier analysis, P = 0.003, 0.015, log-rank test). In multivariate analysis, only 24-hour MOPP fluctuation was significantly associated with central VF progression (P = 0.014). Conclusions The 24-hour MOPP fluctuation was the most consistent prognostic factor among various IOP, blood pressure, and clinical factors for central VF glaucomatous progression in our series of NTG eyes.
- Published
- 2011
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