덧눈꺼풀 교정술이 난시의 개선에 미치는 영향

강완석,안민.Wan Seok Kang. MD. Min Ahn. MD. PhD 대한안과학회 2014 대한안과학회지 Vol.55 No.3

Purpose: To evaluate the changes in visual acuity and astigmatism after epiblepharon surgery regarding preoperative age and astigmatism. Methods: We retrospectively reviewed the charts of 37 patients with epiblepharon surgery. Preoperative best-corrected visual acuity and degree of astigmatism were obtained. Postoperative data were collected at 6 and 12 months. Results: The mean patient age was 5.7 ± 2.5 years. In the 5-9 year-old group and ≤3D group, significant improvement of mean BCVA was demonstrated (p = 0.02, p = 0.039, respectively). In the cylinder groups, 1-2 D, 2-3 D, and ≤3D showed decreased mean astigmatism (p = 0.006, p = 0.034, p = 0.015, respectively). Conclusions: Significant astigmatic reduction was found after surgical correction in epiblepharon patients with higher baseline astigmatism. These results suggest that an epiblepharon surgery should be considered in patients with a high levels of astigmatism. J Korean Ophthalmol Soc 2014;55(3):343-347

양악수술 후 발생한 코눈물관막힘 1예

강완석,안민,Wan Seok Kang,Min Ahn 대한안과학회 2013 대한안과학회지 Vol.54 No.5

Purpose: To describe a case of nasolacrimal duct obstruction after two-jaw surgery. Case summary: A 22-year-old woman presented with a 1-year history of epiphora after two-jaw surgery. Orbital CT showed 5 mm of focal soft tissue at the level of the distal nasolacrimal duct. Dacryocystography showed complete obstruction at the nasolacrimal duct level. Thus a nasolacrimal duct obstruction was diagnosed by physical and radiologic examination. Conclusions: In patients with epiphora who have undergone two-jaw surgery, precise examination and treatment is required in order to exclude nasolacrimal duct obstruction.

Retardation Free In-plane Switching Liquid Crystal Display with High Speed and Wide-view Angle

강완석,문제욱,이기동,이승희,이준호,김병구,최현철 한국광학회 2011 Current Optics and Photonics Vol.15 No.2

In this paper, we propose an in-plane switching (IPS) mode for liquid crystal displays (LCDs) that,in principle, is free of retardation of the LC cell. Basically, the optical configuration of the LC cell consists of an A-plate and an LC layer for switching between the dark and bright states. We could achieve a fast response time compared with the conventional in-plane LC cell because the free retardation condition of the proposed LC cell enables us to reduce the cell gap even by quarter-wave retardation without any change of the optimized LC material in the transmissive mode. Experiments for verification of the proposed in-plane switching LC cells have shown a significant reduction of the rising time and falling time simultaneously due to the small cell gap. Furthermore, we also proposed an optical configuration for wide viewing property of the retardation free IPS LCD by applying the optical films. We proved the wide-view property of the retardation free IPS LCD by comparing its optical luminance with the calculated optical property of the conventional IPS LCD.

폐경전후 여성에 있어서 혈장 지질농도변화와 골밀도 비교

강완석,장판기,정기령,이은희 한국건강관리협회 1999 건협 Report Vol.2 No.-

GMT 평판의 볼트조인트 강도 평가

강완석,민지현,이재욱,임용택 대한기계학회 2003 大韓機械學會論文集A Vol.27 No.10

당뇨병 환자에서 당뇨망막병증 중증도에 따른 눈물막의 변화

강완석,최현태,안민,유인천,Wan Seok Kang,Hyun Tae Choi,Min Ahn,In Cheon You 대한안과학회 2014 대한안과학회지 Vol.55 No.4

Purpose: To determine the relationship between changes in the tear film according to the classification of diabetic retinopathy in patients with diabetes. Methods: A total of 117 newly detected diabetic patients were included in this study. The classification of diabetic retinopathy was performed based on the Early Treatment Diabetic Retinopathy Study (ETDRS). The duration of diabetes and HbA1c were also investigated in patients who had undergone panretinal photocoagulation or insulin treatment. To examine the tear film function, we performed the tear break-up time test, the Schirmer I test, and the diagnostic fluorescein staining test of the ocular surface. The Cochet-Bonnet esthesiometer was also employed to examine the corneal sensitivity. Results: As the severity of diabetic retinopathy progressed, the degree of ocular surface fluorescein staining increased significantly. There was no relationship between the duration of diabetes and the results of the tear film function test. Patients who had high blood HgA1c levels showed significant increases in tear break-up time and degree of ocular surface fluorescein staining. The patients who had undergone panretinal photocoagulation showed significant differences in tear break-up time and degree of ocular surface fluorescein staining. Conclusions: The diabetic patients with progressed diabetic retinopathy, uncontrolled blood HgA1c levels and who had previously undergone panretinal photocoagulation should be managed more carefully since those patients are more susceptible to ocular surface disorder with aggravation of tear film function. J Korean Ophthalmol Soc 2014;55(4):486-492

고분자 안정화 블루상 액정셀의 전기광학특성 향상을 위한 지그재그 형태 전극 설계

강완석,문병준,이기동,Kang, Wan-Seok,Mun, Byung-June,Lee, Gi-Dong 한국정보통신학회 2011 한국정보통신학회논문지 Vol.15 No.1

고분자 안정화 블루상 액정셀(Polymer-stabilized blue phase liquid crystal cell)은 ${\mu}s$ 단위의 응답속도와 광시야각 및 액정의 배향을 위한 문지름 과정이 필요 없는 장점이 있다. 그러나 높은 구동전압과 낮은 kerr 상수값으로 인해 유도되는 복굴절의 값이 낮아 고분자 안정화 블루상 액정셀의 전기광학특성을 저해하는 요인이 되었다. 본 논문에서는 지그재그 형태의 전극 구조를 제안하고 시뮬레이션을 통하여 제안된 전극 구조를 가지는 액정셀의 투과율 손실 없이 구동전압을 25%이상 낮출 수 있음을 확인하였다. The polymer-stabilized blue phase liquid crystal (BPLC) cell has advantages such as sub-millisecond response time, wide viewing angle and no rubbing process for the alignment of liquid crystals. However, high operating voltage and low kerr constant of the polymer-stabilized blue phase liquid crystal deteriorate the electro-optical characteristic of the polymer-stabilized BPLC cell. In this paper, we proposed novel zig-zag electrode in cell layout and confirmed that proposed electrode shape could reduce an over 25 percent of operating voltage for BPLC cell without degradation of tranmittance by using Kerr constant simulation.

생쥐를 이용한 스테로이드 유발 고안압 모델

김유라,강완석,권의용,조남천,이동욱,You Ra Kim,Wan Seok Kang,Eui Yong Kweon,Nam Chun Cho,Dong Wook Lee 대한안과학회 2014 대한안과학회지 Vol.55 No.8

Purpose: To determine whether rat eyes develop increases in intraocular pressure (IOP) in response to a topically applied corticosteroid and to investigate the relationship between ocular hypertension and apoptosis of retinal ganglion cells. Methods: IOP was monitored by rebound tonometry in a group of 10 rats that received topically administered dexamethasone in both eyes (experimental) and in another group of 5 rats that received artificial tears (control) three times daily for 4 weeks after the establishment of baseline IOP values. Only eyes that increased by more than 50% compared with the basal IOP were administered once per day for 5 weeks. After 8 weeks, selective immunofluorescence stain for retinal ganglion cells and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) stain were conducted. Results: Among 20 experimental eyes, 11 eyes (55%) showed a greater than 50% increase in IOP compared with basal IOP. After 8 weeks, the mean IOPs for the experimental and control groups were 11.8 ± 1.4 mm Hg and 18.5 ± 1.0 mm Hg, respectively (<em>p</em> < 0.01). The counts of central retinal ganglion cells (RGCs) were 2718 ± 240 and 2612 ± 443, respectively (<em>p</em> = 0.294). The results of the TUNEL stain also showed no differences. Conclusions: Rat eyes exhibit a steroid-induced ocular hypertensive response with no local complications. However, maintaining ocular hypertension increased by 50% for two months was not enough to detect changes in RGCs. J Korean Ophthalmol Soc 2014;55(8):1202-1207

Intramyocardial Injection of Stem Cells in Pig Myocardial Infarction Model: The First Trial in Korea

김민철,김용숙,강완석,이기홍,조미영,홍문화,임경섭,정명호,안영근 대한의학회 2017 Journal of Korean medical science Vol.32 No.10

Although cell therapy is emerged for cardiac repair, its efficacy is modest by intracoronary infusion. Therefore, we established the intramyocardial delivery technique using a left ventricular (LV) mapping system (NOGA® XP) using 18 pigs. After adipose tissue-derived mesenchymal stem cells (ATSCs) were delivered intramyocardially to porcine infarcted heart, LV ejection fraction (EF) was increased, and LV chamber size was decreased. We proved the therapeutic effect of intramyocardial injection of ATSC through a LV mapping system in the porcine model for the first time in Korea. The adoption of this technique may accelerate the translation into a clinical application in the near future.

Homeotropic Aligned Liquid Crystal Molecules in Dye-sensitized Solar Cells for High Efficiency

김현경,허승열,강완석,이기동,진성호 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.56 No.5

We optimized the alignment of the embedded liquid crystal (LC) molecular in quasi-solid state dye-sensitized solar cells (DSSC) to enhance the photovoltaic performance. The aligned LC molecular increases the ordering strength in the electrolyte so that it can provide a better pathway to transfer generated charges inside the polymer electrolyte. We performed experiments with three types of electrolytes, a typical polymer electrolyte, a polymer electrolyte with LC, and a polymer electrolyte with an aligned LC. The electro-optical characteristics obtained from these experiments were compared with each other for validation. We found that the aligned LCs in a polymer electrolyte can provide higher photovoltaic performance than conventional electrolytes.