Han Woong Lim
Hanyang University
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Featured researches published by Han Woong Lim.
Retina-the Journal of Retinal and Vitreous Diseases | 2014
Han Woong Lim; Joong Won Shin; Hee Yoon Cho; Ha Kyoung Kim; Se Woong Kang; Su Jeong Song; Hyeong Gon Yu; Jae Ryung Oh; Jae Suk Kim; Sang Woong Moon; Ju Byung Chae; Tae Kwann Park; Yumi Song
Purpose: To identify the clinical features, treatment outcomes, and prognostic factors of endogenous endophthalmitis in multiple tertiary referral centers of South Korea over a 6-year period. Methods: The authors conducted a retrospective review of medical records of 57 eyes of 43 patients diagnosed with endogenous endophthalmitis from January 2005 to December 2011, which was referred to tertiary referral centers. Results: Fifty-seven cases of 43 patients were followed for a mean of 18.7 months (range, 0.5–50 months). The common underlying diseases were diabetes mellitus (46.5%) and liver cirrhosis (20.93%). Liver abscess (39.5%) was the most common infection source. Among prognostic factors, the initial visual acuity was associated with favorable visual outcome significantly (P < 0.001). Endogeneous endophthalmitis with gram-negative bacteria had worse visual outcomes than gram-positive bacteria or fungus (P = 0.014). Conclusion: Similar to the findings of previous East Asian studies, this study showed that Klebsiella pneumoniae was the most common causative organism of endogenous endophthalmitis and liver abscess was the most common infection focus. Although endogenous endophthalmitis is generally associated with poor visual acuity outcomes, the prognosis depends mainly on the initial visual acuity and the pathogen.
Ophthalmology | 2014
Han Woong Lim; Dong Eik Lee; Jung Wook Lee; Min Ho Kang; Mincheol Seong; Hee Yoon Cho; Jae-Eung Oh; Sei Yeul Oh
PURPOSE To measure the maximum angle of ocular versions using photographs of the 9 cardinal positions and a modified limbus test. DESIGN An evaluation of diagnostic technology; a prospective observational study. PARTICIPANTS We enrolled 104 healthy subjects, 20 to 40 years of age. METHODS Photographs were obtained in the 9 cardinal positions of gaze and the images were processed using Photoshop. The images were analyzed using the Image J program to measure the angle of version. The maximum angle of the 9 cardinal positions was quantified using a modified limbus test. MAIN OUTCOME MEASURES We measured the maximum angle of ocular versions in the 9 cardinal positions of gaze. We also compared the results for males and females. RESULTS The mean angles of maximum version were adduction 47.4°, abduction 46.4°, elevation 31.8°, depression 47.8°, elevation in adduction 39.7°, elevation in abduction 40.7°, depression in adduction 52.7°, and depression in abduction 49.2°. The mean angle of maximum elevation was significantly smaller than that of depression (P <0.001). There were no correlations between the angle of maximum version and age, spherical equivalents, or axial length. The angle of maximum version for males was significantly greater than that for females, except for inferior gaze. CONCLUSIONS A modified limbus test using photographs of the 9 cardinal positions is an objective and reproducible tool for quantifying ocular movement. Considering its simplicity, ease of use, and low cost, it has clear applications in clinical practice.
American Journal of Ophthalmology | 2014
Han Woong Lim; Jung Wook Lee; Eunhee Hong; Yumi Song; Min Ho Kang; Mincheol Seong; Hee Yoon Cho; Sei Yeul Oh
PURPOSE To report a novel method for measuring the degree of inferior oblique muscle overaction and to investigate the correlation with other factors. DESIGN Cross-sectional diagnostic study. METHODS One hundred and forty-two eyes (120 patients) were enrolled in this study. Subjects underwent a full orthoptic examination and photographs were obtained in the cardinal positions of gaze. The images were processed using Photoshop and analyzed using the ImageJ program to measure the degree of inferior oblique muscle overaction. Reproducibility or interobserver variability was assessed by Bland-Altman plots and by calculation of the intraclass correlation coefficient (ICC). The correlation between the degree of inferior oblique muscle overaction and the associated factors was estimated with linear regression analysis. RESULTS The mean angle of inferior oblique muscle overaction was 17.8 ± 10.1 degrees (range, 1.8-54.1 degrees). The 95% limit of agreement of interobserver variability for the degree of inferior oblique muscle overaction was ±1.76 degrees, and ICC was 0.98. The angle of inferior oblique muscle overaction showed significant correlation with the clinical grading scale (R = 0.549, P < .001) and with hypertropia in the adducted position (R = 0.300, P = .001). The mean angles of inferior oblique muscle overaction classified into grades 1, 2, 3, and 4 according to the clinical grading scale were 10.5 ± 9.1 degrees, 16.8 ± 7.8 degrees, 24.3 ± 8.8 degrees, and 40.0 ± 12.2 degrees, respectively (P < .001). CONCLUSIONS We describe a new method for measuring the degree of inferior oblique muscle overaction using photographs of the cardinal positions. It has the potential to be a diagnostic tool that measures inferior oblique muscle overaction with minimal observer dependency.
Korean Journal of Ophthalmology | 2014
Dong Eik Lee; Ju Hyang Lee; Han Woong Lim; Min Ho Kang; Hee Yoon Cho; Mincheol Seong
Purpose To evaluate the effect of pattern scan laser (PASCAL) photocoagulation on peripapillary retinal nerve fiber layer (RNFL) thickness, central macular thickness (CMT), and optic nerve morphology in patients with diabetic retinopathy. Methods Subjects included 35 eyes for the PASCAL group and 49 eyes for a control group. Peripapillary RNFL thickness, cup-disc area ratio and CMT were measured before PASCAL photocoagulation and at 2 and 6 months after PASCAL photocoagulation in the PASCAL or control groups. Results The average RNFL thickness had increased by 0.84 µm two months after and decreased by 0.4 µm six months after PASCAL photocoagulation compared to baseline, but these changes were not significant (p = 0.83, 0.39). The cup-disc area ratio was unchanged after PASCAL photocoagulation. CMT increased by 18.11 µm (p = 0.048) at two months compared to baseline thickness, and partially recovered to 11.82 µm (p = 0.11) at six months in the PASCAL group. Conclusions PASCAL photocoagulation may not cause significant change in the peripapillary RNFL thickness, CMT, and optic nerve morphology in patients with diabetic retinopathy.
Medicine | 2017
Yong Un Shin; Han Woong Lim; Eun Hee Hong; Min Ho Kang; Mincheol Seong; Eunwoo Nam; Heeyoon Cho
Abstract Periodontal disease (PD) is associated with various systemic diseases. We investigated the association between PD and age-related macular degeneration (AMD). For this population-based, cross-sectional study, we enrolled 13,072 adults at least 40 years of age with gradable retinal fundus photographs and community periodontal index (CPI) data from the Korean National Health and Nutrition Examination Survey (KNHANES) (2008–2010 and 2012). Participants were divided into a middle age group (age ⩽62 years) and old age group (age >62 years). PD was divided into 2 categories of mild and severe. Logistic regression analysis was used to evaluate the association between PD and AMD (early and late). The prevalence of PD and AMD in the study population was 37.4% ± 0.8% and 5.6% ± 0.2%, respectively. Overall, there was no significant difference in the proportion of participants with PD between those with and without AMD. Only participants with AMD in the middle age group had more any PD than those without AMD (P = 0.031). Multivariate logistic regression model after adjusting for all confounding factors showed that PD was not significantly associated with AMD (odds ratio [OR] 1.03, 95% confidence interval [CI] 0.86–1.22). However, according to degree of PD, participants with severe PD in the middle age group were 1.61 times more likely to have AMD (OR 1.61, 95% CI 1.02–2.54). Our data, collected from an Asian population, showed that only severe PD is independently associated with AMD in individuals aged 62 years or younger.
Korean Journal of Ophthalmology | 2016
Jung Wook Lee; In Seok Song; Ju-Hyang Lee; Yong Un Shin; Han Woong Lim; Won June Lee; Byung Ro Lee
Purpose To evaluate the thickness and volume of the choroid in healthy Korean children using swept-source optical coherence tomography. Methods We examined 80 eyes of 40 healthy children and teenagers (<18 years) using swept-source optical coherence tomography with a tunable long-wavelength laser source. A volumetric macular scan protocol using the Early Treatment Diabetic Retinopathy Study grid was used to construct a choroidal thickness map. We also examined 44 eyes of 35 healthy adult volunteers (≥18 years) and compared adult measurements with the findings in children. Results The mean age of the children and teenagers was 9.47 ± 3.80 (4 to 17) vs. 55.04 ± 12.63 years (36 to 70 years) in the adult group (p < 0.001, Students t-test). Regarding the Early Treatment Diabetic Retinopathy Study subfields, the inner temporal subfield was the thickest (247.96 µm). The inner and outer nasal choroid were thinner (p = 0.004, p = 0.002, respectively) than the surrounding areas. The mean choroidal volumes of the inner and outer nasal areas were smaller (p = 0.004, p = 0.003, respectively) than those of all the other areas in each circle. Among the nine subfields, all areas in the children, except the outer nasal subfield, were thicker than those in adults (p < 0.05). Regression analysis showed that age, axial length, and refractive error correlated with subfoveal choroidal thickness (p < 0.05). Conclusions Overall macular choroidal thickness and volume in children and teenagers were significantly greater than in adults. The nasal choroid was significantly thinner than the surrounding areas. The pediatric subfoveal choroid is prone to thinning with increasing age, axial length, and refractive error. These differences should be considered when choroidal thickness is evaluated in children with chorioretinal diseases.
PLOS ONE | 2015
Kyung-Ah Park; In-Jeong Lyu; Jung-Min Yoon; Un-Chang Jeong; Jae-Eung Oh; Han Woong Lim; Sei Yeul Oh
To present the surgical outcomes of a muscle union procedure in patients with paralytic strabismus, this retrospective study included 27 patients with paralytic strabismus who underwent a muscle union procedure. In this procedure, the two vertical rectus muscles are united with the paralytic horizontal muscle without splitting the muscles. Postoperative ocular deviations, complications, surgical success rates, and reoperation rates were obtained by examining the medical records of the patients. Seventeen patients had a sixth cranial nerve palsy, seven patients had a third cranial nerve palsy, and three patients had a medial rectus muscle palsy after endoscopic sinus surgery. The mean preoperative angle of horizontal deviation in the primary position was 56 ± 21 prism diopters. The mean follow-up period was 12 ± 9 months. The mean final postoperative ocular deviation was 8 ± 13 prism diopters. The success rate was 74%, and the reoperation rate was 0%. No significant complications, including anterior ischemia, occurred in any of the patients. One patient exhibited an increase in intraocular pressure in the immediate postoperative period, but this resolved spontaneously within 1 week. Our muscle union procedure was effective in patients with paralytic strabismus, especially in patients with a large angle of deviation. This muscle union procedure is potentially a suitable option for muscle transposition in patients with paralytic strabismus who have large-angle deviation or a significant residual angle after conventional surgery.
Journal of Cataract and Refractive Surgery | 2014
Min Ho Kang; Mincheol Seong; Han Woong Lim; Hee Yoon Cho
During 2010 and 2011, we reported a rate of endophthalmitis of 0.14 per 1000 in the Diablo Service Area of Kaiser Permanente; this low rate corresponded to adoption of intracameral injections at the end of cataract surgery among all patients treated in that medical center. In recent years and in response tomounting evidence of the effectiveness and safety of intracameral injections of antibiotic in preventing cataract surgery–related endophthalmitis, our network of surgeons across the entire Northern California region of Kaiser Permanente (including the Diablo Service Area and 15 other service areas) has increased adoption of intracameral antibiotics at the end of cataract surgery. Some surgeons currently prefer cefuroxime as a first-line drug; others use moxifloxacin. In cases of allergy, a small percentage of patients receive vancomycin. Following publication of our 2010–2011 experience and as part of our mission to provide high-quality care to our patients, we took steps to increase implementation of intracameral injections systemwide. From January 1 to December 31, 2013, an increasing proportion of our cataract surgery patients received intracameral antibiotics, with an average proportion of 79% for the calendar year, similar to the proportion reported in Europe. Using the same case definition that we used in our previous report, we calculated the rate of endophthalmitis for the calendar year 2013 in the entire Northern California region. Among 32 562 routine phacoemulsification procedures, we observed 3 cases of endophthalmitis. One of these occurred among 6891 procedures performed without intracameral injections (rate 0.14 per 1000; 95% confidence interval [CI], 0.00-0.80 per 1000); the pathogen was methicillinresistant Staphylococcus aureus. The 2 other cases occurred among 25671 procedures with intracameral injections (rate 0.08 per 1000; 95% CI, 0.00-0.28 per 1000). One case that received intracameral moxifloxacin occurred the day after surgery; the etiology was coagulase-negative Staphylococcus species. The second case, which received intracameral cefuroxime, involved Enterococcus faecalis endophthalmitis following removal of sutures 30 days after uneventful cataract surgery. This resulted in a Seidel-positive wound; a contact lens was placed and ofloxacin drops were prescribed 2 days prior to clinical signs of infection. Arguably, this second case would not have been affected by
PLOS ONE | 2018
Won June Lee; Yu Jeong Kim; Ji Hong Kim; Sunjin Hwang; Seung Hak Shin; Han Woong Lim
Purpose To investigate the effect of eye movement on the optic nerve head (ONH) using swept-source optical coherence tomography (SS-OCT), and to measure the degree of ONH changes. Methods We enrolled 52 healthy subjects, 20 to 40 years of age, and performed a prospective observational study. Both ONH and macula were imaged simultaneously using wide volume scan of the SS-OCT in the primary and different gaze positions. Horizontal eye movements were used to obtain OCT images in abducted and adducted eyeball positions. Multilateral 3-dimensional registration was used to process and analyze the images to measure the degree of ONH changes. Results The mean axial length (AXL) was 25.73 ± 1.42mm and the mean spherical equivalents was -4.49 ± 2.94 D (The proportion of high myopia was 39.4%). Significant morphologic changes were observed in the ONH during both abduction and adduction. In abduction, the overall ONH tissues were elevated, and the mean area of elevation was 115,134 ± 9,424 μm2 (p<0.001). In adduction, the mean areas from two perspectives, which were nasal or temporal, and peripapillary tissues or optic nerve cupping were 95,277 ± 73,846 μm2, 34,450 ± 44,948 μm2, -108,652 ± 91,246 μm2, and -30,581 ± 46,249 μm2, respectively. Elevation in abduction (overall, nasal cup segment, and temporal cup segment; R = 0.204, 0.195 and 0.225, p = 0.038, 0.047 and 0.021, respectively) and elevation of nasal peripapillary segments in adduction were positively correlated with AXL (R = 0.346, p<0.001). Conclusion We found significant morphologic changes in the ONH in both abduction and adduction and these changes were associated with AXL. Considering these morphologic changes as physical properties, it allows a better understanding of the biomechanical characteristics of the ONH.
PLOS ONE | 2018
Ju-Yeun Lee; Han Woong Lim; Jung-Min Yoon; Jae Eung Oh; Kyung-Ah Park; Sei Yeul Oh
Aim To investigate the performance of a newly developed three-dimensional (3D) biomechanical model in various transposition procedures for correction of complete sixth nerve palsy with educational purpose. Methods A 3D biomechanical eye model was created using Hyperworks software based on geometry data and the biochemical properties of the eyeball and extraocular muscles. A complete sixth nerve palsy model was achieved via modification of lateral rectus muscle strength. Four different muscle transposition procedures (the Hummelsheim, Jensen, Foster, and muscle union procedures) were set up, and the objective surgical effect of each procedure was calculated using 3D model simulation. Results In the 3D simulation, sixth nerve palsy was modeled by rotating the eye 34.16 degrees in the medial direction, consistent with 70 prism diopter (PD) esotropia. In surgical model simulation, the Hummelsheim procedure resulted in a 28 PD reduction of total deviation, the Jensen procedure achieved a 34 PD reduction, the Foster procedure led to a 57 PD reduction, the muscle union procedure yielded a 57 PD reduction in esotropia in sixth nerve palsy. Conclusion The 3D simulation provided a consistent model of sixth nerve palsy and objective data excluding the potential for variation of surgical skill. It could also help predict surgical outcomes.