Publications by authors named "Kyu H Park"

Objective Accurate and timely interpretation of chest radiographs is essential for assessing respiratory distress and guiding clinical management to improve outcomes of critically ill newborns. This study aimed to introduce a deep learning-based automated algorithm designed to classify various neonatal respiratory diseases and healthy lungs using a large dataset of high-quality, multi-class labeled chest X-ray images from neonatal intensive care units (NICUs). Methods Portable supine chest X-ray images for six common conditions (healthy lung, respiratory distress syndrome (RDS), transient tachypnea of the newborn (TTN), air leak syndrome (ALS), atelectasis, and bronchopulmonary dysplasia (BPD)) and demographic variables (gestational age and birth weight) were retrospectively collected from 10 university hospitals in Korea.

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Purpose: To investigate the clinical characteristics of Korean patients with pericentral retinitis pigmentosa (RP) and to identify clinical biomarkers associated with rapid visual acuity decline based on baseline factors.

Methods: This retrospective study included 59 eyes of 31 patients diagnosed with pericentral RP. Comprehensive ophthalmological examinations and genetic sequencing were conducted to assess the baseline characteristics.

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Background: Leber congenital amaurosis (LCA), the most severe form of inherited retinal dystrophy, is a rare, heterogeneous, genetic eye disease associated with severe congenital visual impairment. RPE65, one of the causative genes for LCA, encodes retinoid isomerohydrolase, an enzyme that plays a critical role in regenerating visual pigment in photoreceptor cells.

Methods: Exome sequencing (ES) was performed on a patient with suspected LCA.

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Purpose: To investigate the clinical course and prognostic factors of age-related macular degeneration (AMD) without macular neovascularization (MNV) in patients presenting with pigment epithelial detachment (PED) and the associated subretinal fluid (SRF).

Methods: Morphological characteristics of spectral-domain optical coherence tomography images were analyzed to determine anatomic outcomes. Factors associated with the progression to late AMD, defined as complete retinal pigment epithelium and outer retinal atrophy (cRORA) or MNV, were investigated.

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Purpose: To investigate the clinical implications of choroidal hyperreflective foci (HF) as biomarkers of disease severity in Stargardt disease (STGD).

Methods: 129 eyes from 66 patients with STGD were included. The primary outcome was the correlation between the number of foveal choroidal HF and indicators of disease severity.

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Article Synopsis
  • Parkinson's disease (PD) is a progressive movement disorder becoming more common due to an aging population, and researchers aimed to explore rare genetic variants that could help explain its development.
  • Whole-exome sequencing was conducted on a large group of PD cases and controls of Asian ancestry, revealing significant links between the genes GBA1 and SMPD1 and the risk of developing PD, confirmed in additional samples.
  • The research found that specific SMPD1 variants that reduced enzyme activity were particularly associated with PD risk, with a prominent Asian-specific variant being common among carriers.
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Purpose: To evaluate the clinical usefulness of a deep learning-based detection device for multiple abnormal findings on retinal fundus photographs for readers with varying expertise.

Methods: Fourteen ophthalmologists (six residents, eight specialists) assessed 399 fundus images with respect to 12 major ophthalmologic findings, with or without the assistance of a deep learning algorithm, in two separate reading sessions. Sensitivity, specificity, and reading time per image were compared.

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  • Diabetic macular edema (DME) is a serious eye condition that can cause blindness and costs a lot of money to treat with special drugs.
  • A study looked at three years of medical costs for patients with DME and compared them to patients with diabetes but without DME.
  • The results showed that patients with DME spent more than double on medical costs compared to those without DME.
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Purpose: The purpose of this study was to develop a deep learning model for predicting the axial length (AL) of eyes using optical coherence tomography (OCT) images.

Methods: We retrospectively included patients with AL measurements and OCT images taken within 3 months. We utilized a 5-fold cross-validation with the ResNet-152 architecture, incorporating horizontal OCT images, vertical OCT images, and dual-input images.

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Purpose: To investigate the intraocular concentration profiles of stem cell factor (SCF)/c-KIT, galectin-1 (GAL-1), and vascular endothelial growth factor (VEGF)-A with regard to retinal disease and treatment response.

Methods: The study group included 13 patients with dry age-related macular degeneration (AMD), 196 with neovascular AMD (nAMD), 21 with diabetic macular edema (DME), 10 with retinal vein occlusion (RVO), and 34 normal subjects with cataracts. Aqueous humor levels of SCF, c-KIT, GAL-1, and VEGF-A were analyzed by immunoassay according to disease group and treatment response.

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Purpose: To investigate the significance of intravitreal anti-vascular endothelial growth factor treatment in patients with neovascular age-related macular degeneration and poor visual acuity.

Methods: Retrospective study of patients with neovascular age-related macular degeneration with baseline best-corrected visual acuity of ≤20/200. Patients were divided into regular treatment and scarce treatment groups according to whether they underwent consecutive intravitreal anti-vascular endothelial growth factor treatments at intervals of ≤4 months or not.

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Purpose: The gonadotropin-releasing hormone (GnRH) stimulation test is the gold standard for diagnosing central precocious puberty (CPP). Gonadorelin (Relefact) is used for the test but is not always readily available; triptorelin is used as an alternative. The purpose of this study was to evaluate the diagnostic validity of the triptorelin test compared with the GnRH test in the diagnosis of CPP in girls.

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Article Synopsis
  • The study aimed to evaluate the long-term effectiveness and safety of brolucizumab (BRZ) injections in patients with typical neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV).
  • It included 401 patients over a follow-up period of at least 12 months, assessing visual acuity, retinal fluid, and central subfield thickness (CST), with positive results noted across both patient groups.
  • Brolucizumab maintained visual acuity and significantly improved retinal fluid management; however, there were instances of intraocular inflammation, with some cases leading to severe complications after treatment.
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Stomata are pores on plant aerial surfaces, each bordered by a pair of guard cells. They control gas exchange vital for plant survival. Understanding how guard cells respond to environmental signals such as atmospheric carbon dioxide (CO2) levels is not only insightful to fundamental biology but also relevant to real-world issues of crop productivity under global climate change.

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Small interfering RNA (siRNA) is known for its ability to silence the expression of specific genes, demonstrating its promising potential as a therapeutic approach. Self-assembled micelle inhibitory RNA (SAMiRNA) is an oligonucleotide duplex developed to overcome the in vivo delivery limitations of siRNA. SAMiRNA has hydrophilic and hydrophobic groups at both ends of a sense strand, forming a spherical nanostructure that enhances the in vivo delivery efficiency.

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The aim of this study was to introduce novel vector field analysis for the quantitative measurement of retinal displacement after epiretinal membrane (ERM) removal. We developed a novel framework to measure retinal displacement from retinal fundus images as follows: (1) rigid registration of preoperative retinal fundus images in reference to postoperative retinal fundus images, (2) extraction of retinal vessel segmentation masks from these retinal fundus images, (3) non-rigid registration of preoperative vessel masks in reference to postoperative vessel masks, and (4) calculation of the transformation matrix required for non-rigid registration for each pixel. These pixel-wise vector field results were summarized according to predefined 24 sectors after standardization.

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Article Synopsis
  • The introduction of biologic medicines that target VEGF has greatly enhanced treatment outcomes for patients with retinal diseases, but their high costs can limit access to care.
  • Biosimilars, which are cheaper alternatives that are proven to be clinically equivalent to branded agents, offer a potential solution to financial barriers in treatment.
  • Since 2022, anti-VEGF biosimilars have begun to emerge in the US ophthalmology market, prompting a review of their regulatory background, development challenges, and the implications for patient care.
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Complex living systems are thought to exist at the "edge of chaos" separating the ordered dynamics of robust function from the disordered dynamics of rapid environmental adaptation. Here, a deeper inspection of 72 experimentally supported discrete dynamical models of cell processes reveals previously unobserved order on long time scales, suggesting greater rigidity in these systems than was previously conjectured. We find that propagation of internal perturbations is transient in most cases, and that even when large perturbation cascades persist, their phenotypic effects are often minimal.

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Objective: To determine perinatal risk factors for Massive pulmonary hemorrhage (MPH) and MPH-caused mortality to guide clinicians in implementing preventive measures at the beginning of life for improving the survival of very low birth weight infant (VLBWIs).

Study Design: A total of 13,826 VLBWIs born between 2013 and 2020 in the Korean Neonatal Network database were included.

Results: MPH occurred in 870 (6.

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To compare the efficacy of scleral buckling with adjuvant pneumatic retinopexy (SB with PR) and scleral buckling (SB) alone for primary rhegmatogenous retinal detachment (RRD). This retrospective and comparative study included patients who underwent SB with PR (n = 88) or SB alone (n = 161) for primary RRD. The primary anatomical success rate for SB with PR was 81.

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Congenital and infantile (CI) cataract is one of the most important and preventable cause of blindness in children, but the incidence has not been studied in Korea. We collected data from the national claims database of the National Health Insurance Service of Korea from 2002 through 2019. We identified children who underwent cataract surgery within the age of 5 years, and cumulative incidence rates were calculated for each of the three age criteria.

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Article Synopsis
  • The study focuses on investigating microvascular changes in the retina and choroid at different stages of retinitis pigmentosa (RP), which is a chronic eye disease.
  • Researchers classified RP into three stages based on the integrity and width of the inner segment ellipsoid zone and analyzed retinal blood flow using optical coherence tomography angiography.
  • Findings showed that as RP progresses, there's a decrease in the density of blood vessels in the early stage, leading to an increase in the area of the foveal avascular zone in advanced stages.
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This study investigates the impact of glycosylated hemoglobin (HbA1c) on the efficacy of intravitreal dexamethasone (DEX) implants in patients with diabetic macular edema (DME) over a 12-month period. We retrospectively reviewed 90 DME patients treated with DEX implants, categorizing them based on baseline HbA1c levels (≤ 7% and > 7%) and 12-month changes in HbA1c ("improved", "stable", "worsened"). At the 2-month mark, the mean central subfield thickness (CST) reduction in the HbA1c ≤ 7% group was - 147.

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Purpose: To investigate the incidence and morphological biomarkers to predict the exudative conversion in eyes with type 1 nonexudative macular neovascularization using swept-source optical coherence tomography angiography.

Methods: Macular neovascularizations were detected using the retinal pigment epithelium-to-retinal pigment epithelium-fit slab of swept-source optical coherence tomography angiography scan. Depending on whether exudation developed within a year, the eyes were divided into two groups: active and silent.

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