Sang In Khwarg

Seoul National University Hospital, Sŏul, Seoul, South Korea

Are you Sang In Khwarg?

Claim your profile

Publications (105)

  • Source
    Jinku Park · Sang In Khwarg · Jeong Hoon Choi · [...] · Ho Kyung Choung
    Full-text Article · Aug 2016 · Korean Journal of Ophthalmology
  • Bo Ram Seol · Ho-Kyung Choung · Namju Kim · [...] · Sang In Khwarg
    [Show abstract] [Hide abstract] ABSTRACT: Importance: Epiblepharon is known to be bilateral and symmetric. However, asymmetric epiblepharon is frequently observed in patients with head tilt and, to date, this condition has not been investigated. Objectives: To evaluate the clinical features of epiblepharon in patients with head tilt and to analyze the association between the direction of head tilt and epiblepharon asymmetry. Design, setting, and participants: The medical records of 1074 Korean children who received a diagnosis of epiblepharon between January 1, 2006, and October 31, 2013, at Seoul National University Bundang Hospital were retrospectively reviewed. The data collected included sex, age, extent and asymmetric presentation of epiblepharon, and direction and cause of head tilt. Main outcomes and measures: The presence of epiblepharon asymmetry in patients with head tilt as well as the association between the direction of head tilt and the side having more severe epiblepharon. Results: Of 1074 patients (536 boys; mean [SD] age, 5.4 [2.6] years) with epiblepharon, 38 individuals (3.5%) showed head tilt. The causes of head tilt were superior oblique palsy (18 patients [47.4%]), congenital muscular torticollis (10 [26.3%]), dissociated vertical deviation (3 [7.9%]), and unknown (7 [18.4%]). Asymmetric epiblepharon was more common in children with vs without head tilt (34 [89.5%] vs 80 [7.7%]; P < .001, Fisher exact test). Of the 34 patients with head tilt and asymmetric epiblepharon, the direction of head tilt was consistent with the side having more severe epiblepharon in 29 individuals (85.3%) and inconsistent in 5 individuals (14.7%) (P = .009). Conclusions and relevance: These data suggest that, in patients with epiblepharon and head tilt, epiblepharon is most often asymmetric and is severe in the head-tilted side. These results suggest that patients with asymmetric epiblepharon should be evaluated for head tilt.
    Article · May 2016 · Jama Ophthalmology
  • Source
    Chan Joo Ahn · Nam Ju Kim · Ho Kyung Choung · [...] · Sang In Khwarg
    Full-text Article · Jan 2016 · Journal of the Korean Ophthalmological Society
  • Source
    Kyu Hwan Jang · Nam Ju Kim · Ho Kyung Choung · Sang In Khwarg
    [Show abstract] [Hide abstract] ABSTRACT: To investigate the surgical results of early and delayed repair of orbital wall fracture after multiple subgrouping of patients by time between the operation and injury.
    Full-text Article · Jan 2016 · Journal of the Korean Ophthalmological Society
  • Source
    Eu Noo Bak · Jin Suk Ryu · Sang In Khwarg · Joo Youn Oh
    [Show abstract] [Hide abstract] ABSTRACT: To report a case of ocular surface squamous cell carcinoma with intraorbital extension in a patient with renal transplantation and long-term immunosuppressive therapy.
    Full-text Article · Jan 2016 · Journal of the Korean Ophthalmological Society
  • Source
    [Show abstract] [Hide abstract] ABSTRACT: Ocular adnexal IgG4-related sclerosing disease (IgG4-SD) has been categorized as a novel disease entity. It is characterized by stromal sclerosis and an infiltration of mass-forming lymphoplasmic cells containing many IgG4-positive plasma cells. Although ocular adnexal tissue involvement has been increasingly reported, a focal nodular sub-brow mass is not typical in an IgG4-SD presentation. We report a rare case of probable ocular adnexal IgG4-SD that clinically mimicked eyelid pilomatrixoma. A 42-year-old woman presented with a nodular mass in her left sub-brow area. The initial clinical impression of her lesion was eyelid pilomatrixoma. However, the final pathologic diagnosis was IgG4-SD, but extranodal marginal zone B-cell lymphoma could not be excluded. The patient underwent testing to determine tumor malignancy and systemic IgG4-SD involvement. Laboratory testing showed normal IgG and IgG4 serum levels and imaging revealed no remarkable findings. Oral prednisolone was administered and slowly tapered to manage the possible remnant lesion and to prevent disease recurrence. Two years after initiating therapy, there was no evidence of relapse. The patient is under close surveillance for signs of recurrence, systemic involvement, and potential malignant transformation. We found an unusual case of probable ocular adnexal IgG4-SD, which presented as a unilateral restricted mass involving the sub-brow area. Although the mass was surgically removed, systemic steroid treatment and long-term surveillance were initiated due to the possibility of recurrence, the potential association with systemic disease, and the potential development of extranodal mucosa-associated lymphoid tissue (MALT) lymphoma.
    Full-text Article · Dec 2015 · BMC Ophthalmology
  • J A Kim · N Kim · H-K Choung · [...] · S I Khwarg
    [Show abstract] [Hide abstract] ABSTRACT: PurposeIntratarsal keratinous cysts (IKCs) have been frequently misdiagnosed as chalazia or epidermal cysts. We reviewed a series of cases of IKCs to identify clinical features that distinguish IKCs from other eyelid diseases.Methods We retrospectively reviewed the medical records of 17 suspected IKC patients between January 2004 and September 2014.ResultsSeventeen patients who were clinically suspected to have IKC were enrolled. All patients presented with non-inflamed eyelid nodules fixed to the tarsus. Among them, 12 biopsy specimens were available and 11 patients (91.7%) were diagnosed with IKC, with a pathological finding of stratified squamous cell lining with keratin material. The mean patient age was 55.1 years (31-71). Six patients had a surgical history of incision or incomplete excision of the lesion, followed by recurrence. On eyelid eversion, five patients showed a white-yellow nodule, and three patients had a bluish cystic lesion. The diameter of the nodules ranged from 4 to 10 mm. The intracystic material was a milky white fluid. Ten patients underwent a complete surgical excision including partial tarsectomy and there was no recurrence.ConclusionsIKC can be distinguished from other intratarsal lesions by a characteristic tarsal nodule fixed to the tarsus. To prevent recurrence, complete excision with partial tarsectomy is needed.Eye advance online publication, 2 October 2015; doi:10.1038/eye.2015.184.
    Article · Oct 2015 · Eye (London, England)
  • Hokyung Choung · Young A Kim · Namju Kim · [...] · Sang In Khwarg
    [Show abstract] [Hide abstract] ABSTRACT: Purpose The incidence and clinical correlation of MALT1 translocation and chromosomal numerical aberrations in Korean patients with ocular adnexal mucosa associated lymphoid tissue (MALT) lymphoma have not yet been reported. We investigated the incidence and clinicopathologic relationship of these chromosomal aberrations in ocular adnexal MALT lymphomas in a Korean population. Methods Thirty ocular adnexal MALT lymphomas were investigated for the t(11;18) API2-MALT1, t(14;18) IgH-MALT1 translocations and chromosomes 3 and 18 aneuploidies using fluorescence in situ hybridization. Patient medical records were reviewed retrospectively for information on demographics and clinical characteristics, including treatment response. Results The MALT1 gene rearrangement was found in one out of 30 cases. The t(14;18) IgH-MALT1 translocation was demonstrated in only one case (3.3%), and the t(11;18) API2-MALT1 translocation was not found in any of the cases. Trisomy 3 was observed in three ocular adnexal MALT lymphomas (10.0%), and five cases showed trisomy 18 (16.7%). Translocation positive cases also showed trisomy 18. One case of tumor relapse showed trisomy 18 only in the recurrent biopsies. There were no statistically significant correlations between chromosomal aberrations and clinical characteristics and treatment responses. Conclusions Translocations involving the MALT1 gene are not common in Korean ocular adnexal MALT lymphomas. The t(14;18) translocation was detected in only one out of 30 cases, and the t(11;18) translocation was not found at all. Furthermore, the chromosomal aberrations found in this study had no prognostic implications.
    Article · Sep 2015 · Korean Journal of Ophthalmology
  • [Show abstract] [Hide abstract] ABSTRACT: To investigate the therapeutic potential of TNF-α stimulated gene/protein (TSG)-6 in two mouse models of inflammation-mediated dry eye syndrome (DES). We created inflammation-mediated DES in mice by injecting concanavalin A (ConA; 10 mg/mL) into intraorbital and extraorbital lacrimal glands. Recombinant TSG-6 (1 μg in phosphate-buffered solution [PBS]) or the same volume of PBS was administered topically to eyes of the mice four times a day (QID) for 1 week. In parallel experiments, we topically applied TSG-6 (1 μg) or PBS QID to eyes of 12-week-old NOD.B10.H2b mice, a model for primary Sjögren's syndrome. Seven days later, tear production was measured, and the corneal surface was observed for epithelial defects. The number of goblet cells was evaluated in the forniceal conjunctiva. The levels of proinflammatory cytokines were analyzed in the cornea, conjunctiva, and lacrimal glands. Also, in vitro experiments were performed using cultures of corneal epithelial cells (CECs) to test the effects of TSG-6 on cell proliferation and migration. Topical TSG-6 administration improved tear production and reduced corneal epithelial defects both in ConA-injected mice and NOD.B10.H2b mice. The conjunctival goblet cell density was higher in TSG-6-treated eyes than in PBS-treated eyes. The expression of proinflammatory cytokines in the cornea, conjunctiva, and intraorbital gland was repressed by TSG-6, while the levels of proinflammatory cytokines in the extraorbital gland were not changed. In vitro experiments revealed that TSG-6 promoted the migration of CECs, but did not affect the proliferation. Topical TSG-6 protected the ocular surface by suppressing inflammation and promoting corneal epithelial wound healing.
    Article · Aug 2015 · Investigative ophthalmology & visual science
  • Dataset · Jul 2015
  • [Show abstract] [Hide abstract] ABSTRACT: To identify crucial molecular alterations of receptor tyrosine kinases that can be used as potential therapeutic targets for eyelid sebaceous gland carcinoma (SbGC). The expression levels of HER2, EGFR, C-MET, and FGFR1 were determined by immunohistochemistry (IHC). The copy numbers of the HER2, EGFR, C-MET, and FGFR1 genes were assessed by fluorescence in situ hybridization. The IHC and molecular results were correlated with the clinical parameters. A total of 49 patients with eyelid SbGC were included in this study. HER2, EGFR, C-MET, and FGFR1 protein expression was detected in 8 of 44 (16.3 %), 8 of 45 (17.8 %), 3 of 35 (8.6 %), and 0 of 45 patient samples, respectively. Increased copy numbers of the HER2 gene were found in 5 of 42 patient samples (11.9 %), including two with amplification (4.7 %) and three with polysomy (7.2 %). EGFR amplification was found in 2 of 33 (6.1 %) and FGFR1 amplification in 4 of 33 patient samples (12.1 %; high-level amplification in one and low-level amplification in three). None of the samples examined exhibited C-MET amplification. Gene copy number of the HER2 gene was correlated with its protein expression (p < 0.0001), whereas copy number of EGFR, C-MET, or FGFR1 was not correlated with protein expression. However, samples with EGFR amplification also exhibited a high level of expression of this protein. Extra copies of the HER2, EGFR, and FGFR1 genes were identified in a 6-12 % of eyelid SbGCs. A high level of concordant HER2 expression detected by immunohistochemistry can be predictive of a copy number gain of the HER2 gene. Our data suggest that the therapeutic targeting of HER2 might benefit for a subset of patients with periocular SbGCs.
    Article · Jul 2015 · Journal of Cancer Research and Clinical Oncology
  • Dataset · Jul 2015
  • Source
    [Show abstract] [Hide abstract] ABSTRACT: This study aims to analyze clinical and pathological characteristics of ocular adnexal extranodal marginal zone B-cell lymphoma (EMZL) accompanying IgG4-positive cells. Fifty patients with a diagnosis of primary non-conjunctival ocular adnexal EMZL were enrolled in this study. The number of IgG4-positive cells and the ratio of IgG/IgG4 were evaluated by immunohistochemistry in the biopsy specimens. The patients were divided into two groups based on the absolute number and the ratio of IgG4-positive cells (IgG4-posivite vs IgG4-negative groups). The demographic data, clinical staging at diagnosis, histopathological characteristics, and response to initial treatment were comparatively analyzed between the 2 groups. Five (10%) of 50 patients were defined as IgG4-positive group, and all the cases showed characteristic histological features such as extensive plasma cell infiltration and dense fibrosis. Most of these patients (4 of 5 patients) had lymphoma of the lacrimal gland. The patients from the IgG4-positive group showed a lower response rate to initial treatment (87.5 vs 33%, p = 0.03) than IgG4-negative group with a median follow-up period of 38 months. A part of the ocular adnexal EMZLs were accompanied with IgG4-positive cells. Significantly, most IgG4-positive ocular adnexal EMZLs occurred in the lacrimal gland, and can be related with a more frequent treatment failure.
    Full-text Article · Jun 2015 · PLoS ONE
  • [Show abstract] [Hide abstract] ABSTRACT: Purpose: To investigate the expression of cancer stem cell (CSC) marker proteins in eyelid sebaceous gland carcinoma and evaluate the clinical significance. Methods: Archival tissue blocks from 50 cases of eyelid sebaceous gland carcinoma were tested via immunohistochemistry for 16 putative CSC markers. Levels of protein expression were analyzed alongside various clinicopathologic parameters such as metastasis-free survival time. Results: Ten patients (20%) showed nodal or distant metastasis during the follow-up period (median 35.2 months, range 1-128 months) without any mortality in our series. Among the 16 markers, ALDH1, CD44, CD133, ABCG2, Sox4, Sox9 and slug were selected for candidates of CSC markers because they were frequently and predominantly found in the tumor cells compared to control tarsus cells which showed negative or very low expression. Univariate analysis revealed that ALDH1, CD133, and ABCG2 were significantly associated with metastasis; patients with ALDH1- or CD133-positive tumors developed metastasis more frequently than patients with tumors that were negative for these markers (log-rank test, p = 0.014, p = 0.013, respectively), and diffuse expression of ABCG2 was associated with significantly shorter metastasis-free survival (log-rank test, p = 0.010). Multivariate Cox proportional hazard model revealed that ALDH1 (hazard ratio [HR] = 5.682, p = 0.038) was significantly associated with metastasis. Conclusions: Development of metastasis in eyelid sebaceous gland carcinoma might be attributed to increased number of CSCs or acquisition of dedifferentiated phenotype. Our findings suggest that CSCs are involved in the disease progression of eyelid sebaceous gland carcinoma, and in particular, expression of ALDH1 is a predictor of a poor outcome. Copyright © 2015 by Association for Research in Vision and Ophthalmology.
    Article · Feb 2015 · Investigative Ophthalmology & Visual Science
  • Youn Joo Choi · In Hyuk Kim · Jeong Hoon Choi · [...] · Sang In Khwarg
    [Show abstract] [Hide abstract] ABSTRACT: There is a paucity of data in the literature on the surgical management of conjunctival dermolipoma. In this study, we report outcomes of a partial mass excision technique (excision of the portion visible when eyes open) and free conjunctival autograft. Medical records of 13 patients with dermolipoma who had undergone partial mass excision at Seoul National University Hospital from January 1999 to May 2014 were retrospectively reviewed. After resection of the visible part of tumour, including the overlying thick surface conjunctiva, the conjunctival defects were reconstructed with free conjunctival autograft harvested from the contralateral superior bulbar area. The median postoperative follow-up period was 5 months (range 1-84 months). The cosmetic surgical results were satisfactory in all 13 patients. Three patients showed thick texture on the grafted surgical area postoperatively, but there was no significant scar formation resulting in restrictive symblepharon or eye movement limitation. There were no other significant complications, such as blepharoptosis, diplopia or keratoconjunctivitissicca during the follow-up period. Partial mass (visible part only) excision, including that of the overlying thick conjunctiva, and free conjunctival autograft from the opposite eye, is a relatively simple and effective technique for the surgical management of conjunctival dermolipoma. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to
    Article · Jan 2015 · British Journal of Ophthalmology
  • Source
    Byeong Soo Kang · Nam Ju Kim · Ho Kyung Choung · Sang In Khwarg
    [Show abstract] [Hide abstract] ABSTRACT: Basal cell carcinoma is the most common malignant neoplasm of the skin. Periorbital basal cell carcinoma needs to be treated for cosmetic improvement and prevention of intraorbital invasion. Although surgical excision is a standard treatment, nonsurgical treatment using imiquimod cream, a topical immunomodulator, has been attempted. The authors report the first case of periorbital basal cell carcinoma successfully treated with imiquimod cream; to the best of our knowledge, similar cases have not been published to date in the Korean ophthalmology journals.
    Full-text Article · Jan 2015 · Journal of the Korean Ophthalmological Society
  • [Show abstract] [Hide abstract] ABSTRACT: Ocular adnexal lymphoma (OAL) has been associated with Chlamydophila psittaci infection, for which doxycycline has been suggested as a treatment option. We conducted this study to evaluate the long-term results of first-line doxycycline treatment in patients with OAL. Ninety patients with histologically confirmed OAL with marginal zone B cell lymphoma were enrolled. Each patient received one or two cycles of doxycycline (100 mg bid) for 3 weeks. After a median follow-up period of 40.5 months (8-85), the 5-year progression-free survival (PFS) rate was 60.9 %. All patients were alive at the last follow-up date. Thirty-one patients (34 %) showed local treatment failure without systemic spread. However, PFS rate in these patients was 100 % after salvage chemotherapy and/or radiotherapy. PFS was independently predicted in multivariate analysis by the tumor-node-metastasis (TNM) staging (hazard ratio [HR], 4.35; 95 % confidence interval [CI], 2.03-9.32; P < 0.001) and number of cycles of doxycycline (HR, 0.31; 95 % CI, 0.14-0.69; P = 0.004). No serious adverse event was reported during doxycycline therapy. In conclusion, first-line doxycycline therapy was effective and safe. Patients who failed to respond to doxycycline therapy were successfully salvaged with chemotherapy and/or radiotherapy without compromising long-term outcomes. Patients with T1N0M0 disease could be considered good candidates for first-line doxycycline.
    Article · Oct 2014 · Annals of Hematology
  • Source
    [Show abstract] [Hide abstract] ABSTRACT: Dry eye syndrome (DES) is one of the most common ocular diseases affecting nearly 10% of the U.S. population. Most of the currently-available treatments are palliative, and few therapeutic agents target biological pathway of DES. Although DES is a multifactorial disease, it is well-known that inflammation in the ocular surface plays an important role in the pathogenesis of DES. Mesenchymal stem/stromal cells (MSCs) have been shown to repair tissues by modulating excessive immune responses in various diseases. Therefore, we here investigated the therapeutic potential of MSCs in a murine model of an inflammation-mediated dry eye that was induced by an intraorbital injection of concanavalin A. We found that a periorbital administration of MSCs reduced the infiltration of CD4(+) T cells and the levels of inflammatory cytokines in the intraorbital gland and ocular surface. Also, MSCs significantly increased aqueous tear production and the number of conjunctival goblet cells. Subsequently, corneal epithelial integrity was well-preserved by MSCs. Together, the results demonstrate that MSCs protect the ocular surface by suppressing inflammation in DES, and suggest that MSCs may offer a therapy for a number of ocular surface diseases where inflammation plays a key role.Molecular Therapy (2014); doi:10.1038/mt.2014.159.
    Full-text Article · Aug 2014 · Molecular Therapy
  • Source
    Min Joung Lee · Byung-Joo Min · Ho-Kyung Choung · [...] · Sang In Khwarg
    [Show abstract] [Hide abstract] ABSTRACT: Purpose To compare genome-wide DNA methylation profiles according to Chlamydophila psittaci (Cp) infection status and the response to doxycycline treatment in Korean patients with ocular adnexal extranodal marginal zone B-cell lymphoma (EMZL). Methods Twelve ocular adnexal EMZL cases were classified into two groups (six Cp-positive cases and six Cp-negative cases). Among the 12 cases, eight were treated with doxycycline as first-line therapy, and they were divided into two groups according to their response to the treatment (four doxy-responders and four doxy-nonresponders). The differences in the DNA methylation states of 27,578 methylation sites in 14,000 genes were evaluated using Illumina bead assay technology. We also validated the top-ranking differentially methylated genes (DMGs) with bisulfite direct sequencing or pyrosequencing. Results The Infinium methylation chip assay revealed 180 DMGs in the Cp-positive group (74 hypermethylated genes and 106 hypomethylated genes) compared to the Cp-negative group. Among the 180 DMGs, DUSP22, which had two significantly hypomethylated loci, was validated, and the correlation was significant for one CpG site (Spearman coefficient=0.6478, p=0.0262). Regarding the response to doxycycline treatment, a total of 778 DMGs were revealed (389 hypermethylated genes and 336 hypomethylated genes in the doxy-responder group). In a subsequent replication study for representative hypomethylated (IRAK1) and hypermethylated (CXCL6) genes, the correlation between the bead chip analysis and pyrosequencing was significant (Spearman coefficient=0.8961 and 0.7619, respectively, p<0.05). Conclusions Ocular adnexal EMZL showed distinct methylation patterns according to Cp infection and the response to doxycycline treatment in this genome-wide methylation study. Among the candidate genes, DUSP22 has a methylation status that was likely attributable to Cp infection. Our data also suggest that the methylation statuses of IRAK1 and CXCL6 may reflect the response to doxycycline treatment.
    Full-text Article · Jul 2014 · Molecular vision
  • Min Joung Lee · Ji Eun Kim · Namju Kim · [...] · Sang In Khwarg
    [Show abstract] [Hide abstract] ABSTRACT: To investigate the clinical and histopathological features of inflammatory lesions of the lateral canthal subconjunctival area. This is a retrospective case series of 12 patients with inflammatory subconjunctival masses in the lateral canthal area. All patients included in this study were treated at Seoul National University Hospital or Seoul National University Bundang Hospital between 2006 and 2012. Clinical data were obtained from the medical records. Histopathologic findings were thoroughly reviewed. There was a woman predominance in the study group (10:2), and the median age at presentation was 39 years (range 33-70). Common symptoms included conjunctival injection, sticky discharge, and pain or discomfort. Histopathologically, all lesions originated from ductules of the lacrimal gland. Two cases showed cysts containing clear fluid with mild inflammation. One case showed lacrimal ductulitis without cyst formation. Nine cases showed lacrimal ductal cysts with varying periductal inflammation, and the contents were pinkish, amorphous materials in 7 cases. Embedded cilia were found in 8 cases. Inflammatory lesions of the lateral canthal subconjunctival area all originated from lacrimal gland ductules, showing a variable histopathologic spectrum of inflammation and cyst formation. Cilia impaction was a very frequently observed finding.
    Article · May 2014 · Ophthalmic plastic and reconstructive surgery