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Dive into the research topics where Byunghoon Chung is active.

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Featured researches published by Byunghoon Chung.


American Journal of Ophthalmology | 2014

Effects of topical loteprednol etabonate on tear cytokines and clinical outcomes in moderate and severe meibomian gland dysfunction: randomized clinical trial

Hun Lee; Byunghoon Chung; Kyu Seo Kim; Kyoung Yul Seo; Bong Joon Choi; Tae-im Kim

PURPOSE To assess tear cytokine levels and clinical outcomes in moderate and severe meibomian gland dysfunction (MGD) after 2 months of treatment with topical loteprednol etabonate and eyelid scrubs with warm compresses vs eyelid scrubs with warm compresses alone. DESIGN Randomized controlled trial. METHODS Patients with moderate and severe MGD were randomized into 2 groups: topical loteprednol etabonate and eyelid scrubs with warm compresses (Group I, 34 eyes) or eyelid scrubs with warm compresses (Group II, 36 eyes). We evaluated cytokine levels, tear film break-up time (TBUT), corneal and conjunctival fluorescein staining, biomicroscopic examination of lid margins and meibomian glands, and the Ocular Surface Disease Index before initiating treatment and 1 month and 2 months after treatment. RESULTS There were significant decreases in the levels of interleukin (IL)-6, IL-8, and IL-1β in Group I, and IL-6 and IL-8 in Group II. Moreover, the observed decreases of these cytokines in Group I were attributed to a remarkable decrease between treatment and 1 month after treatment. In Group I, there were improvements in all of the clinical outcomes, with prominent improvement in TBUT, corneal and conjunctival fluorescein staining, and meibum quality after 1 month of treatment, compared with Group II. An improvement in meibomian gland expressibility and MGD stage reduction were more remarkable in Group I. CONCLUSIONS Topical loteprednol etabonate and eyelid scrubs with warm compresses were tolerated and efficacious for the treatment of moderate and severe MGD. We suggest that such beneficial effects could manifest after 1 month.


British Journal of Ophthalmology | 2015

Influence of visual acuity on suicidal ideation, suicide attempts and depression in South Korea

Tyler Hyungtaek Rim; Christopher Seungkyu Lee; Sung Chul Lee; Byunghoon Chung; Sung Soo Kim

Background To assess the influence of visual acuity (VA) on suicidal ideation, suicide attempts and depression. Methods From 2008 to 2012, a total of 28 919 nationally representative participants aged 19 years or older in the Korea National Health and Nutrition Examination Survey underwent additional ophthalmological examinations by the Korean Ophthalmologic Society. Associations between best corrected VA in the better-seeing eye based on decimal fraction and mental health were identified using multivariable logistic regression analysis after adjusting for possible biopsychosocial confounders. Self-reported mental health (suicidal ideation, suicide attempt and depression), Euro Quality of Life-Visual Analog Scale and counselling experience were evaluated by direct interviews. A nomogram for risk of suicidal ideation was generated. Results By multivariable logistic regression analysis, low VA was significantly associated with suicidal ideation and suicide attempt but not depression. Participants with a VA of no light perception to 0.2 had a nearly twofold and threefold increased risk of suicidal ideation (adjusted OR, 1.85; 95% CI 1.04 to 3.27) and suicidal attempt (adjusted OR, 3.44; 95% CI 0.92 to 12.79), compared with participants with a VA of 1.0. Sociodemographic disparities, including age and socioeconomic status, existed for suicidal ideation, suicidal attempt and depression. Euro Quality of Life-Visual Analog Scale significantly decreased as VA decreased and was lower in participants who attempted suicide. Conclusions Low VA was associated with the occurrence of suicidal ideation or a suicide attempt. Ophthalmologists should embrace their responsibility to help reduce suicidality and prevent suicides in patients with low VA by encouraging them to seek psychiatric care.


American Journal of Ophthalmology | 2014

Dynamic vaulting changes in V4c versus V4 posterior chamber phakic lenses under differing lighting conditions.

Hun Lee; Sung Yong Kang; Kyoung Yul Seo; Byunghoon Chung; Jin Young Choi; Kyu Seo Kim; Tae-im Kim

PURPOSE To compare vaulting changes in eyes implanted with V4c and V4 implantable collamer lenses (ICLs) under differing lighting conditions. DESIGN Noninterventional, cross-sectional comparative observational case series. METHODS Fifty-six eyes of 38 patients implanted with V4c ICLs, and 54 eyes of 28 patients implanted with V4 ICLs were enrolled and analyzed. Anterior chamber depth, pupil size and postoperative vaulting were evaluated using a Visante optical coherence tomography system under photopic and mesopic conditions 1 month postoperatively. Refractive errors, keratometry values, axial lengths, intraocular pressures, anterior chamber volumes, and central corneal thicknesses were also recorded. RESULTS No significant differences were noted in anterior chamber depth between photopic and mesopic conditions in either group. Significant decreases in vaulting and pupil size were detected under photopic conditions in both groups. Moreover, vaulting changes in eyes implanted with V4c ICLs were significantly larger than those in eyes implanted with V4 ICLs. CONCLUSIONS V4c ICL vaulting decreased more prominently under photopic conditions than did V4 ICL vaulting. Therefore, postoperative vaulting under mesopic and photopic conditions should be considered when interpreting the vaulting of eyes implanted with V4c ICLs.


Graefes Archive for Clinical and Experimental Ophthalmology | 2016

Fundus autofluorescence findings in central serous chorioretinopathy using two different confocal scanning laser ophthalmoscopes: correlation with functional and structural status

Joo Youn Shin; Hun Jin Choi; Jong Hyun Lee; Moonjung Choi; Byunghoon Chung; Suk Ho Byeon

PurposeTo compare autofluorescence (AF) findings using wide-field (Optomap) and conventional (HRA-AF) confocal scanning laser ophthalmoscopy (cSLO) systems in patients with central serous chorioretinopathy (CSC), and to investigate the correlations between AF findings and functional and anatomical status.MethodsOptical coherence tomography (OCT) and AF images were compared in 73 eyes with serous retinal detachment (SRD) (group A) and 30 eyes without SRD (group B). We evaluated AF findings from the SRD region, atrophic area, and foveola. Correlations between AF findings and outer retinal abnormalities in OCT and visual acuity (VA) were analyzed.ResultsOptomap-AF was more effective than HRA-AF in identifying the margins of a detached area (P = 0.001) in group A, and for monitoring mild outer retinal damage (P = 0.041) in group B. The foveolar AF grades in both instruments were significantly correlated with VA and central foveal thickness (CFT) in both group A (Optomap, VA rs = 0.33, P = 0.012; CFT rs = −0.38, P = 0.002; HRA, VA rs = 0.62, P < 0.001; CFT rs = −0.70, P < 0.001) and group B (Optomap, VA rs = 0.71, P < 0.001, CFT rs = −0.78, P < 0.001; HRA, VA rs = 0.40, P = 0.026, CFT rs = −0.40, P = 0.030).ConclusionsOptomap-AF was found to be advantageous for monitoring subretinal status in eyes with SRD, and more accurately reflected mild outer retinal changes in eyes without SRD. Foveolar AF grades of both imaging modalities were significantly correlated with functional and anatomical status.


Optometry and Vision Science | 2016

Anti-Vascular Endothelial Growth Factor with Gas for Submacular Hemorrhage.

Joo Youn Shin; Hun Jin Choi; Byunghoon Chung; Moonjung Choi; Jong Hyun Lee; Suk Ho Byeon

Purpose To investigate the treatment outcome of pneumatic displacement and intravitreal anti–vascular endothelial growth factor (VEGF) for submacular hemorrhage (SMH) from exudative age-related macular degeneration (AMD). Methods Best-corrected visual acuity (BCVA) and central foveal thickness (CFT) were measured at baseline and at 1, 3, and 6 months after initial treatment in 72 eyes of 72 patients treated with a combination of pneumatic displacement and anti-VEGF injection for SMH from exudative AMD. Results Best-corrected visual acuity and CFT showed significant improvement from baseline during the 6-month follow-up period (logarithm of the minimum angle of resolution BCVA from 1.80 to 1.00, CFT from 886 to 383 &mgr;m, p < 0.001, respectively). The decrease in subretinal hemorrhage was greater than that in subretinal pigment epithelial hemorrhage at 1 month after initial treatment (p < 0.001). In eyes with symptoms for less than 30 days, higher reflectivity of hemorrhage on optical coherence tomography and higher CFT were associated with lower BCVA after 6 months of treatment (reflectivity B = 0.335, p = 0.007; CFT B = 0.001, p = 0.003). Conclusions The combination of pneumatic displacement and intravitreal anti-VEGF is a useful treatment option for SMH secondary to AMD. Higher baseline CFT and higher reflectivity of hemorrhage were associated with lower BCVA 6 months after initial treatment.


International Journal of Ophthalmology | 2018

Preloaded and non-preloaded intraocular lens delivery system and characteristics: human and porcine eyes trial

Byunghoon Chung; Hun Lee; Moonjung Choi; Kyoung Yul Seo; Eung Kweon Kim; Tae-im Kim

AIM To compare characteristics of preloaded and non-preloaded intraocular lens (IOL) delivery systems during IOL delivery procedures. METHODS Total 101 human eyes were included in this prospective observational case series. Delivery characteristics of 5 types of IOLs including iSert250 NC60 (NC60), EnVista MX60 (MX60), AcrySof IQ SN60WF (SN60WF), TECNIS ZCB00 (ZCB00), and TECNIS PCB00 (PCB00) were investigated. NC60 and PCB00 were injected via preloaded delivery systems and other IOLs were injected via non-preloaded systems. In the human trial, time taken from IOL loading to completion of implantation was measured in all eyes undergoing conventional cataract surgery. Using 4 excised porcine eyes, dynamics of ophthalmic viscosurgical device (OVD) between an IOL injector and a porcine eye was analyzed using fluorescein sodium-stained OVD. RESULTS The average time for IOL implantation was 22.0s for NC60, 43.2s for MX60, 32.3s for SN60WF, 41.4s for ZCB00, and 14.6s for PCB00 respectively. The number of cases with IOL manipulation with a second instrument was 6 for MX60, 2 for ZCB00, 0 for SN60WF, NC60, and PCB00. Amount of OVD pushed into a porcine eye was smaller with a preloaded system than with non-preloaded systems. CONCLUSION IOL delivery with preloaded systems is faster and more predictable. Moreover, a preloaded delivery system shows relatively less OVD pushed into a porcine eye than non-preloaded systems.


Korean Journal of Ophthalmology | 2017

Clinical Outcomes of an Optimized Prolate Ablation Procedure for Correcting Residual Refractive Errors Following Laser Surgery

Byunghoon Chung; Hun Lee; Bong Joon Choi; Kyung Ryul Seo; Eung Kwon Kim; Dae Yune Kim; Tae-im Kim

Purpose The purpose of this study was to investigate the clinical efficacy of an optimized prolate ablation procedure for correcting residual refractive errors following laser surgery. Methods We analyzed 24 eyes of 15 patients who underwent an optimized prolate ablation procedure for the correction of residual refractive errors following laser in situ keratomileusis, laser-assisted subepithelial keratectomy, or photorefractive keratectomy surgeries. Preoperative ophthalmic examinations were performed, and uncorrected distance visual acuity, corrected distance visual acuity, manifest refraction values (sphere, cylinder, and spherical equivalent), point spread function, modulation transfer function, corneal asphericity (Q value), ocular aberrations, and corneal haze measurements were obtained postoperatively at 1, 3, and 6 months. Results Uncorrected distance visual acuity improved and refractive errors decreased significantly at 1, 3, and 6 months postoperatively. Total coma aberration increased at 3 and 6 months postoperatively, while changes in all other aberrations were not statistically significant. Similarly, no significant changes in point spread function were detected, but modulation transfer function increased significantly at the postoperative time points measured. Conclusions The optimized prolate ablation procedure was effective in terms of improving visual acuity and objective visual performance for the correction of persistent refractive errors following laser surgery.


Acta Ophthalmologica | 2017

Retinal pigment epithelium wound healing after traumatic choroidal rupture

Joo Youn Shin; Byunghoon Chung; Yun Hyup Na; Jong Hyun Lee; Hyewon Chung; Suk Ho Byeon

The aim of this study was to investigate wound healing in the retinal pigment epithelium (RPE) after traumatic indirect choroidal rupture using fundus autofluorescence (FAF) and spectral‐domain optical coherence tomography (SD‐OCT).


Journal of Cataract and Refractive Surgery | 2015

Management of long-standing partially torn and flipped laser in situ keratomileusis flaps

Jin Sun Kim; Byunghoon Chung; Taekjune Lee; Woon Cho Kim; Tae-im Kim; Eung Kweon Kim


Graefes Archive for Clinical and Experimental Ophthalmology | 2015

Pigment epithelial tears after ranibizumab injection in polypoidal choroidal vasculopathy and typical age-related macular degeneration

Joo Youn Shin; Moonjung Choi; Byunghoon Chung; Suk Ho Byeon

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