회절 방식의 다초점 비구면 인공수정체의 단기 임상 결과

장민욱,엄영섭,강수연,김균형,송종석,김효명.Minwook Chang. MD. Youngsub Eom. MD. Su-Yeon Kang. MD. 대한안과학회 2009 대한안과학회지 Vol.50 No.4

Purpose: To compare the clinical outcome between Tecnis ZM900 and Tecnis ZA9003. Methods: We reviewed 20 eyes of 11 patients implanted with Tecnis ZM900 and 20 eyes of 20 patients implanted with Tecnis ZA9003. The clinical outcomes of these two intraocular lenses were evaluated one month after operation and consisted of distant, intermediate, and near visual acuity; depth of focus; contrast sensitivity; wavefront aberration; and patient satisfaction. Six months after the operation a reevaluation was performed for the group who had received the Tecnis ZM 900 implant. Results: Near and intermediate vision was better in the Tecnis ZM900 group. There were no statistical differences between the two groups with respect to distant vision and wavefront aberration. Contrast sensitivity was better in the Tecnis ZA9003 group and depth of focus was deeper in the Tecnis ZM900 group. There were no statically significant differences in the result between one month and six month after the operation. Conclusions: The Tecnis multifocal ZM900 IOL can be effective at improving patient satisfaction after cataract surgery as well as for correcting presbyopia. J Korean Ophthalmol Soc 2009;50(4):529-536

실리콘관을 이용한 코경유 눈물주머니코안연결술 후 발생한 급성 결막염의 임상적 고찰

박진환,장민욱,이태수,Jin-hwan Park,Minwook Chang,Tae Soo Lee 대한안과학회 2011 대한안과학회지 Vol.52 No.7

Purpose: To investigate the incidence and clinical course of acute conjunctivitis after endoscopic dacryocystorhinostomy (DCR) with silicone tube intubation. Methods: A retrospective study was conducted on 547 eyes in 517 patients who had undergone endoscopic DCR with silicone tube intubation between 2005 and 2009. The onset, incidence and symptoms of acute conjunctivitis, the effect of silicone tube intubation on acute conjunctivitis, and the effect of acute conjunctivitis on the success rate of DCR were investigated. Results: The incidence of acute conjunctivitis was 3.8%. The mean age of 21 patients with acute conjunctivitis was 52.6 ± 14.3 years and the mean follow-up period of those was 18.0 ± 6.4 months after surgery. All the cases of acute conjunctivitis were resolved with topical antibiotic treatment after silicone tube removal. The success rates between patients with and without conjunctivitis were not significantly different (80.95% and 88.97%, respectively; p = 0.282). However, 4 patients with surgical failure had a longer time from onset of acute conjunctivitis to the removal of the silicone tube than 17 patients with surgical success (0.22 months and 1.13 months, respectively; p = 0.047). A higher rate (76.2%) of conjunctivitis developed in patients with granuloma around the surgical ostium. Conclusions: A correlation may exist between acute conjunctivitis and granuloma in patients with DCR with silicone tube intubation. Acute conjunctivitis did not appear to influence the surgical results, although a delayed timing of silicone tube removal in patients with conjunctivitis could decrease the success rate. J Korean Ophthalmol Soc 2011;52(7):794-799

의료기기 용혈현상 예측의 개선을 위한 정형화된 점탄성 모델

이승헌(Seunghun Lee),장민욱(Minwook Chang),허남건(Nahmkeon Hur),김원정(Wonjung Kim),강성원(Seongwon Kang) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

의료기기 내부 용혈 현상의 예측을 위한 난류 벽 모델의 적용

이승헌(Seunghun Lee),장민욱(Minwook Chang),강성원(Seongwon Kang),허남건(Nahmkeon Hur),김원정(Wonjung Kim) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12

For medical devices with blood flows, analyzing and reducing hemolysis is a very important topic. The shear stress has been identified as the most important factor for the hemolysis. In turbulent flows, high shear stress values are concentrated near the wall. In case of predicting hemolysis numerically, this leads to a very fine mesh and large computational resource to predict hemolysis accurately. In order to resolve this issue, turbulence wall models are used widely to relax the grid requirements. However, there exists no turbulence wall model for predicting the hemolysis yet. Therefore, the purpose of this study is to develop a turbulence wall model for hemolysis. In order to decrease the numerical error of hemolysis prediction, the blood damage index (BDI) is calculated using different approaches in two divided regions. In a near-wall region, an analytic approach using a modeled velocity profile is used to reduce a numerical error from the sharp velocity gradient in a coarse grid resolution. The Van Driest equation is adopted as the model for the mean velocity profile. In a region far from the wall, a regular numerical discretization is applied. The effectiveness of the proposed wall model is assessed for a few turbulent flows such as the flows inside a channel and cannula. The predicted BDI values present that the proposed wall model shows a significantly improved grid convergence and accuracy compared to a fully numerical approach.

안와종양제거술 이후 발생한 중심망막동맥폐쇄

이상재(Sang Jae Lee),장민욱(Minwook Chang) 대한검안학회 2020 Annals of optometry and contact lens Vol.19 No.3

Purpose: We report a case of central retinal artery occlusion that occurred after orbital tumor removal. Case summary: A 42-year-old man was admitted to the ophthalmology clinic because a mass (1.1 x 1.7 cm) was found in the left orbit in the brain computed tomography performed after a traffic accident. At the time of the examination, the visual acuity of the left eye was 20/20 and the intraocular pressure was 19 mmHg. Left eye was protruded about 1 mm compared to the right eye. In the orbit magnetic resonance imaging, the optic nerve was displaced to medial by mass (1.5 x 1.3 x 1.5 cm). And visual defect was detected in visual field test. And mass excision was performed using the Kronlein approach. The mass was diagnosed as cavernous hemangioma in histologic examination. On the first day after surgery, the visual acuity of the left eye was measured as 20/80. But in the afternoon, visual acuity was decreased to finger-count with speaking that black line was appeared in center of left visual field. Steroid therapy was started under suspecting orbital apex syndrome. However, due to no improvement, fluorescein angiography was performed. And central retinal artery occlusion was diagnosed. Then anterior chamber paracentesis and emergency orbital decompression were performed. Fluorescein angiography was performed again 10 days after decompression and showed reperfusion, but vision was not recovered. Conclusions: Central retinal artery occlusion may occur after orbital surgery. Sudden vision loss without pain must be suspected and careful observation is necessary.

장기간 양파즙을 복용한 환자에서 안과 수술 중 발생한 출혈성 경향 2예

이강민(Kang Min Lee),김마르다(Martha Kim),장민욱(Minwook Chang) 대한검안학회 2021 Annals of optometry and contact lens Vol.20 No.1

Purpose: To report a two cases of bleeding tendency in patient with long-term taking onion-juice undergoing elective ophthalmic surgery. Case summary: (Case 1) A 56-year-old male visited our clinic due to blepharoptosis of both upper eyelid for 2 years. Marginal reflex distance1 was 1.5 mm in the both eyes. According to levator function test, the distance was 10 mm and 11 mm, respectively. In diagnosis blepharoptosis of both eyes, levator advancement operation was performed. During surgery, massive hemorrhage without hemostatsis occurred and took twice the usual operation time. In medical history, physical examination and laboratorial blood test performed prior to surgery, there were no underlying medical disease, including hypertension and diabetes mellitus and abnormal specific findings, but history of long-term taking onion-juice was confirmed through additional medical history taking. (Case 2) A 65-year-old male diagnosed with primary open-angle glaucoma 10 years ago, visited our clinic due to uncontrolled intraocular pressure (IOP) of his left eye. IOP was 29 mmHg in his left eye and uncontrolled by glaucoma eyedrops. There were no underlying medical disease and abnormal laboratorial findings. He underwent trabeculectomy after one week of discontinuation of aspirin. During surgery, hemorrhage without hemostatsis and massive subconjunctival hemorrhage occurred. As in the first case, the history of long-term taking onion-juice was confirmed through additional medical history taking. Conclusions: We should pay attention for the bleeding tendency in patient with long-term taking onion-juice, and physicians may consider careful history taking of foods, such as onion-juice.