Publications by authors named "Tae Kwann Park"

Introduction: The retropupillary iris-claw intraocular lens (RP-IOL) offers a sutureless solution to complications like aphakia, intraocular lens (IOL) dislocation, and opacification post-cataract surgery. Unlike time-consuming, complication-prone traditional methods, RP-IOL potentially reduces surgical time and complications. This study evaluates RP-IOL's clinical outcomes to assess its efficacy and safety.

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Background: Because of the low prevalence of inherited retinal diseases, reports on the distribution of retinitis pigmentosa (RP)-related genes in Korean patients are scarce. The aim of this study was to determine the mutation spectrum and allele frequency and observe the final diagnoses in a Korean cohort clinically diagnosed with RP.

Methods: We used whole-exome sequencing (WES) to analyze a Korean cohort of 100 unrelated patients clinically diagnosed with RP.

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The role of the mitogen-activated protein kinase (MAPK) pathway in choroidal neovascularization (CNV) remains unclear. This study investigates the involvement of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 pathways in CNV development, as well as the therapeutic potential of sprouty 2 (SPRY2), an MAPK inhibitor, in a laser-induced mouse model. The expressions of ERK, JNK, and p38 proteins were analyzed using Western blotting and immunostaining.

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Purpose: To describe in detail the genetic profile, clinical features, and genotype-phenotype correlation of retinitis pigmentosa GTPase regulator (RPGR)-associated X-linked retinitis pigmentosa (RP) in Koreans.

Design: A retrospective multicenter case series.

Methods: This study recruited genetically confirmed RPGR-associated X-linked RP patients from nine tertiary hospitals and clinics across Korea.

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Article Synopsis
  • The study explored the effects of ibrutinib, a BTK/ITK inhibitor, on inflammation in a mouse model of Graves' orbitopathy (GO), emphasizing its therapeutic potential.
  • The research involved administering a recombinant plasmid to mice and measuring serum thyroid hormone levels and inflammatory markers, with a focus on histopathological changes in orbital tissues.
  • Results showed that treatment with ibrutinib significantly reduced inflammatory markers and cytokine levels in the GO mice, indicating that BTK/ITK might play a key role in the inflammatory mechanisms of GO.
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X-linked juvenile retinoschisis (XLRS) is a hereditary retinal degeneration affecting young males caused by mutations in the retinoschisin () gene. We generated human induced pluripotent stem cells (hiPSCs) from XLRS patients and established three-dimensional retinal organoids (ROs) for disease investigation. This disease model recapitulates the characteristics of XLRS, exhibiting defects in RS1 protein production and photoreceptor cell development.

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Human retinal organoids (ROs) have emerged as valuable tools for studying retinal development, modeling human retinal diseases, and screening drugs. However, their application is limited primarily due to time-intensive generation, high costs, and low reproducibility. Quality assessment of RO differentiation is crucial for their application in research.

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Increasing evidence suggests that exosomes are involved in retinal cell degeneration, including their insufficient release; hence, they have become important indicators of retinopathies. The exosomal microRNA (miRNA), in particular, play important roles in regulating ocular and retinal cell functions, including photoreceptor maturation, maintenance, and visual function. Here, we generated retinal organoids (ROs) from human induced pluripotent stem cells that differentiated in a conditioned medium for 60 days, after which exosomes were extracted from ROs (Exo-ROs).

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Purpose: To compare short-term efficacy and safety of intravitreal brolucizumab injection with aflibercept in treatment-naive neovascular age-related macular degeneration (nAMD) patients.

Methods: A total of 59 eyes from 59 treatment-naive nAMD patients in three hospitals were retrospectively reviewed. Of which, 27 patients underwent intravitreal brolucizumab injections and 32 received aflibercept.

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Mutations in the RPE65 gene, associated with Leber congenital amaurosis, early-onset severe retinal dystrophy, and retinitis pigmentosa, gained growing attention since gene therapy for patients with RPE65-associated retinal dystrophy is available in clinical practice. RPE65 gene accounts for a very small proportion of patients with inherited retinal degeneration, especially Asian patients. Because RPE65-associated retinal dystrophy shares common clinical characteristics, such as early-onset severe nyctalopia, nystagmus, low vision, and progressive visual field constriction, with retinitis pigmentosa by other genetic mutations, appropriate genetic testing is essential to make a correct diagnosis.

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Choroidal neovascularization (CNV) is a defining characteristic feature of neovascular age-related macular degeneration (nAMD) that frequently results in irreversible vision loss. The current strategies for the treatment of nAMD are mainly based on neutralizing vascular endothelial growth factor (VEGF). However, anti-VEGF therapies are often associated with subretinal fibrosis that eventually leads to damages in macula.

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Various non-intraocular pressure factors have been identified as possible risk factors for open-angle glaucoma (OAG). However, there is still controversy around the association between OAG and chronic kidney disease (CKD). In this study, we used a nationwide cohort to investigate the risk of OAG in the 12 years following a diagnosis of CKD.

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Retinal organoids derived from human-induced pluripotent stem cells (hiPSC) are powerful tools for studying retinal development as they model spatial and temporal differentiation of retinal cell types. Vertebrate retinal development involves a delicate and coordinated process of retinal progenitor cell (RPC) differentiation, and the mammalian target of rapamycin complex 1 (mTORC1) has been reported to play a significant role in this complex process. Herein, using hiPSC-derived retinal organoids, we identify the time-dependent role of mTORC1 in retinal development, specifically in retinal ganglion cell (RGC) differentiation and the retinal lamination process, during the early stages of retinal organoid (RO) development.

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Previous reports have shown possible association between altered protein levels in aqueous humor (AH) and normal-tension glaucoma (NTG), but the underlying pathogenetic mechanism as well as specific molecular biomarkers for NTG remains still elusive. Here, we aimed to identify novel biomarkers for advanced NTG by analyzing the proteome of patient-derived AH and their correlation with various functional and structural parameters from the visual field test (VF), optical coherence tomography (OCT), and OCT angiography (OCTA). We determined differentially expressed proteins (DEPs) of the AH of patients with advanced NTG (n = 20) using label-free quantitative (LFQ) proteomics with pooled samples and data-independent acquisition (DIA) analysis with individual samples, and the roles of AH DEPs in biological pathways were evaluated using bioinformatics.

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Background: To investigate the clinical findings of choroideremia patients and perform genetic analysis by whole-exome sequencing (WES).

Methods: A total of 94 patients initially diagnosed with retinitis pigmentosa (RP) at another hospital, and who visited our hospital for genetic analysis by WES, were included in the study, along with 64 family members. All subjects underwent comprehensive ophthalmic evaluation, including best-corrected visual acuity, slit lamp examination, fundus photography, fundus autofluorescence (FAF), fluorescein angiography (FAG), visual field (VF), electroretinogram (ERG), and optical coherence tomography (OCT).

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Background/aims: To investigate the role of Wnt signalling in adipogenesis using an in vitro model of Graves' orbitopathy (GO).

Methods: Orbital fat was obtained from patients with GO and non-GO participants for primary orbital fibroblast (OF) culture. Expression levels of Wnt5a, Wnt10b, β-catenin, phospho-β-catenin and cyclin D1 were compared between GO and non-GO OFs.

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Article Synopsis
  • Autophagy is crucial for recycling cellular components, and its malfunction is linked to neurodegeneration, including in glaucoma, where its role in retinal ganglion cell (RGC) survival is unclear.
  • In a glaucoma model induced by increased intraocular pressure (IOP) in rats, researchers found that autophagy levels rose gradually, but early autophagy processes were disrupted shortly after IOP elevation.
  • The study suggests that timing is crucial for autophagy modulation, with early intervention showing potential benefits for RGC survival, indicating a possible new therapeutic strategy for treating glaucoma.
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Background: Neurodegeneration, an early event in the pathogenesis of diabetic retinopathy (DR), precedes clinically detectable microvascular damage. Autophagy dysregulation is considered a potential cause of neuronal cell loss, however underlying mechanisms remain unclear. The mechanistic target of rapamycin (mTOR) integrates diverse environmental signals to coordinate biological processes, including autophagy.

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Purpose: To investigate the genotype and long-term clinical phenotype of patients with Bietti crystalline dystrophy (BCD) in Korea and Japan.

Design: Retrospective case series.

Participants: We analyzed 62 patients with clinical features of BCD who harbor pathogenic biallelic CYP4V2 variants in their homozygote or compound heterozygote.

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The intravitreal (IVT) injection method is a choice when targeting the inner retina for gene therapy. However, the transduction efficiency of adeno-associated virus (AAV) vectors administered by the IVT route is usually low and may be affected by several factors. To improve the transduction efficiency, we developed a novel illuminated long-needle attached injection system and injected AAV2-CMV (cytomegalovirus)-EGFP in front of the retina in rabbit eyes.

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We developed and characterized a canine model of outer retinal degeneration induced by sodium iodate (SI) intravitreal injection after vitrectomy. In the preliminary study, we repeatedly injected SI intravitreally into the eyes of three canines to develop outer retinal degeneration two weeks after vitrectomy. Based on the preliminary study, a single dose of either 1.

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We sought to develop and characterize outer retinal degeneration induced by intravitreal injection of sodium iodate (SI) after vitrectomy in rabbits. To determine the effective dose of SI, the right eyes of 19 male New Zealand white rabbits received an intravitreal injection of SI or sham. Based on the dose-dependence results, 0.

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Adeno-associated viruses (AAVs) are the vector of choice for gene therapy in the eye, and self-complementary AAVs (scAAVs), which do not require second-strand DNA synthesis, can be transduced into cells of the trabecular meshwork (TM). The scAAV transduction patterns in the anterior segment of normotensive eyes have been investigated previously, but those in ocular hypertensive (OHT) eyes have not. We assessed the transduction efficiencies of AAV serotypes 2, 5, and 8 in the anterior-segment structures of the eyes of Sprague-Dawley rats with OHT by circumlimbal suturing, followed 3 days later by intracameral injection of scAAV serotype 2 (scAAV2), scAAV5, or scAAV8 packaged with EGFP.

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Choroidal neovascularization (CNV) is the defining characteristic of the wet subtype of age-related macular degeneration (AMD), which is a rapidly growing global health problem. Previously, we had demonstrated the therapeutic potential of gene therapy against CNV using short hairpin RNA (shRNA) delivered via recombinant adeno-associated virus (rAAV), which abrogates mammalian-to-mechanistic (mTOR) activity in a novel manner by simultaneously inhibiting both mTOR complexes. Both the target and use of gene therapy represent a novel treatment modality against AMD.

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