뇌실주위백질연화증 환자에서 동반된 시신경 위축과 시야 결손 1예

김호윤,최희영,이지웅,Ho Yun Kim,Hee Young Choi,Ji Woong Lee 대한안과학회 2013 대한안과학회지 Vol.54 No.6

Purpose: To report a case of visual field defect and optic atrophy in a patient with periventricular leukomalacia. Case summary: A 22-year-old woman was referred to our hospital for further glaucoma evaluation. She was diagnosed with normal tension glaucoma by her local ophthalmologist. Best corrected visual acuity and intraocular pressure were 1.0 and 16 mm Hg in both eyes, respectively. Fundus examination showed a cup disc ratio of 0.36 in the right eye and 0.34 in the left eye. However, the optic disc had temporal pallor. Red-free photograph and optical coherence tomography showed supratemporal retinal nerve fiber layer atrophy. Visual field examinations revealed inferior visual field defect in both eyes. The patient was born at 34 weeks of gestation with a birth weight of 1600 g. Brain magnetic resonance imaging (MRI) showed periventricular leukomalacia. Conclusions: The author presents a case of periventricular leukomalacia with inferior visual field defect and optic atrophy in a patient who was previously diagnosed with glaucoma. If non-specific clinical features that differ from typical glaucomatous clinical features are observed in a patient with a history of prematurity, a brain MRI can aid the diagnosis.

제품화된 무방부제 힐론 점안제가 각막상피세포에 미치는 영향

김호윤,박영민,이종수,Ho Yun Kim,Young Min Park,Jong Soo Lee 대한안과학회 2014 대한안과학회지 Vol.55 No.11

Purpose: To investigate the biologic effects of preservative-free artificial tear drops on cultured human corneal epithelial cells in vitro. Methods: The effects of preservative-free artificial tear drops (sodium hyaluronate 0.1% (Kynex<SUP>Ⓡ, Alcon, Seoul, Korea), sodium hyaluronate 0.18% (Kynex2<SUP>Ⓡ, Alcon, Seoul, Korea), and sodium hyaluronate 0.3% (Hyaluni eye drops 0.3%<SUP>Ⓡ, Taejoon, Seoul, Korea)) on human corneal epithelial cells were evaluated. Cellular proliferation was determined using MTT (3- (4,5-dimethylthiazol- 2yl)-2,5-diphenyl-2H-tetrazolium bromide) and Ki-67 assays. Cellular migration was determined using CD44 and scratch wound assays. Cell damage was determined using the lactate dehydrogenase (LDH) assay and cellular morphologies using electronic microscopy and inverted microscopy. Results: Proliferation of corneal epithelial cells, as determined by the MTT and Ki-67 assays, was not significantly different between the different eye drops (<EM>p</EM> > 0.05). The measured value of cellular migration after exposure of the sodium hyaluronate 0.3%, as determined by mean CD44 percentage and scratch wound assay, was higher than that of the sodium hyaluronate 0.1% and sodium hyaluronate 0.18%, but the CD44 value was not significantly different (<EM>p</EM> > 0.05). The LDH titer tended to increase as the concentration of sodium hyaluronate increased (<EM>p</EM> > 0.05), but influence on cytoplasm, as determined by electronic microscopy, was not different. Conclusions: Among 3 preservative-free artificial tear drops, sodium hyaluronate 0.3% demonstrated increased migration of corneal epithelial cells. As the concentration of sodium hyaluronate in eye drops increased, the corneal cytotoxicity of corneal epithelial cells also increased. However, there was no significant difference among the 3 tear drops. J Korean Ophthalmol Soc 2014;55(11):1698-1705

리모델링 공동주택단지의 외부공간 성능평가 비교 연구

김호윤 ( Kim Ho-yun ),이상석 ( Lee Sang-suk ),유주은 ( Yu Joo-eun ) 한국환경복원기술학회(구 한국환경복원녹화기술학회) 2016 한국환경복원기술학회지 Vol.19 No.4

In this study, remodeling projects are perceived as a sustainable urban management policy to boost the value of old apartments and stimulate urban regeneration and development. To evaluate the physical environmental performance of external spaces of remodeled apartments, an evaluation model was developed. After applying it to the target places, the following results were obtained. First, analysis of the external space change index of the target apartments revealed that institutional standards are necessary in line with the building arrangement type, parking lot expansion method, and changes in the building-to-land ratio. Second, the score ratio as to the external space change index performance is as follows: safety (48.30); pleasantness (25.90); convenience (18.90); eco-friendliness (14.90). In other words, “safety” had the biggest score ratio. Third, to boost the external space performance of remodeled apartments, the needs of residents and neighboring environmental plans should be considered from a communality standpoint.

중증도에 따른 아벨리노 각막이상증의 공초점주사현미경 소견

박영민,김호윤,이종수,Young Min Park,MD,Ho Yun Kim,MD,Jong Soo Lee,MD,PhD 대한안과학회 2014 대한안과학회지 Vol.55 No.3

Purpose: In this study we analyzed and objectified the characteristics of the Avellino corneal dystrophy patients considering disease severity using in vivo confocal microscopy (IVCM). Methods: Each corneal layer of 36 eyes in 18 patients with Avellino corneal dystrophy was examined using IVCM (ConfoScan 4.0, NIDEK, Co. Ltd., Albignasego, Italy). Patients were classified into 3 groups based on disease severity (mild, moderate, or severe). Results: In the mild group, hyper-reflective granular deposits without dark shadows were observed in the anterior stroma. As the disease progressed, corneal deposits were also found at the posterior stroma and epithelium, and clusters of hyper-reflective corneal deposits resembling stromal opacity were noted. The range of corneal deposits measured using Z-scan optical pachymeter was 111.14 ± 30.95 um in the mild group, 157.47 ± 25.00 um in the moderate group, and 193.42 ± 52.23 um in the severe group (p < 0.05). Conclusions: The origin of the corneal deposits in Avellino corneal dystrophy may be related to corneal stromal cells and distributed from the corneal epithelial layer to the stromal layer. IVCM might be useful for the standardization of disease severity by digitalizing the range of deposits. J Korean Ophthalmol Soc 2014;55(3):361-367

유리체절제술과 내경계막제거술 후 9개월에 지연 폐쇄된 특발성 황반원공 1예

이종헌,김호윤,박성후,이지은,변익수,Jong Heon Lee,Ho Yun Kim,Sung Who Park,Ji Eun Lee,Ik Soo Byon 대한안과학회 2014 대한안과학회지 Vol.55 No.5

Purpose: To report a case of delayed idiopathic macular hole closure after vitrectomy, internal limiting membrane peeling, and gas tamponade. Case summary: A 69-year-old female complained of visual disturbance in her left eye. At presentation, her visual acuity was 20/100 in the left eye. Fundus examination and optical coherence tomography revealed a full-thickness macular hole 489 μm in diameter as well as posterior vitreous detachment. Hence, vitrectomy, concurrent cataract surgery, internal limiting membrane peeling and gas tamponade were performed. One month postoperatively, the hole remained unclosed, although decreased in size to 378 μm. At 2 months, cystoid macular edema developed and postoperatively the hole diameter decreased gradually to 311 μm, 252 μm and 156 μm at 2, 3, and 5 months, respectively. Finally, the hole was closed upon the resolution of macular edema at 9 months. However, the visual acuity of 20/100 remained unchanged. Conclusions: Delayed closure of holes which may be related to cystoid macular edema, can develop after macular hole surgery. J Korean Ophthalmol Soc 2014;55(5):775-779

순환 지연 다이버시티 기법에서의 최적의 순환 지연 값

김용준(Yong June Kim),임민중(Min-Joong Rim),정병장(Byun-Jang Jeong),노태균(Taegyun Noh),김호윤(Ho-Yun Kim),임대운(Dae-Woon Lim) 한국통신학회 2008 韓國通信學會論文誌 Vol.33 No.9C

본 논문은 직교 주파수 분할 다중 반송파(OFDM, orthogonal frequency division multiplexing) 시스템의 다이버시티 효과를 향상시키는 순환 지연 다이버시티(CDD, cyclic delay diversity) 기법에서 최적의 순환 지연 값을 결정하는 방법을 제안한다. 순환 지연 다이버시티 기법에서는 순환 지연 값이 증가함에 따라 다이버시티 효과에 의한 SINR (signal to interference and noise ratio) 이득이 커지는 동시에 채널 추정 오류의 증가에 의한 SINR 손실도 커지는 상반 관계(trade-off)가 존재한다. 다이버시티 효과와 채널 추정 오류의 상반 관계가 존재할 때 제안된 방법을 통해 구한 최적의 순환 지연값을 순환 지연 다이버시티 기법에 적용하면, 목표로 하는 프레임 오류율(FER, frame error rate)을 만족시키기 위한 SINR을 최소화한다. In this paper, we propose a method to determine the optimal cyclic delay value of cyclic delay diversity(CDD) in orthogonal frequency division multiplexing(OFDM) systems. As the cyclic delay value increases, we can get signal to interference and noise ratio(SINR) gain by diversity effect, while SINR loss increases because of channel estimation errors. If the optimal delay value obtained by the proposed method is applied to CDD scheme, we can minimize the required SINR for a given FER(frame error rate) under the above mentioned trade-off.

단품(축/OUTPUT 기어)조립을 위한 온간압입공정 해석

김태진(Tae Jin Kim),강희준(Hee Jun Kang),김철(Chul Kim),주석재(Suck Jae Chu),김호윤(Ho Yun Kim) Korean Society for Precision Engineering 2008 한국정밀공학회지 Vol.25 No.6

연령에 따른 안구건조증의 3% 디쿠아포솔나트륨 점안 효능 비교

이석재(Seok Jae Lee),김호윤(Ho Yun Kim),박영민(Young Min Park),이종수(Jong Soo Lee) 대한안과학회 2016 대한안과학회지 Vol.57 No.5

목적: 60세 전후의 안구건조증 환자에서 3% 디쿠아포솔나트륨 점안액의 나이에 따른 임상 효과를 알아보고자 하였다. 대상과 방법: 68명의 환자를 나이에 따라 60세 미만을 1군 29명(29안), 60세 이상을 2군 39명(39안)으로 나누었다. 3% 디쿠아포솔나트륨의 효용성 평가를 위해 최초 방문, 치료 후 1개월, 2개월, 4개월째 객관적인 지표로 눈물막파괴시간, 쉬르머 I 검사, 각막염색검사를 시행하였고, 주관적인 지표로는 ocular surface disease index (OSDI) 설문지를 시행하여 점수화하였다. 결과: 안구건조증의 두 군 모두에서 3% 디쿠아포솔나트륨 치료 후 1개월, 2개월, 4개월째 눈물막파괴시간, 쉬르머 I 검사, 그리고 OSDI 점수의 유의한 호전이 관찰되었으나, 각막염색점수의 경우 치료 전과 유의한 차이를 보이지 않았다. 나이에 따른 두 군으로 나누어 비교한 결과에서 눈물막파괴시간은 치료 후 1개월째(p=0.012), 2개월째(p=0.005), 4개월째(p=0.001)로 1군에서 2군에 비해 통계적으로 유의한 호전을 보였다. 쉬르머 I 검사의 경우 치료 후 1개월째(p=0.015), 2개월째(p=0.005), 4개월째(p=0.005)로 1군에서 2군에서 보다 유의한 호전을 보였다. 그러나 각막염색점수의 결과와 OSDI 점수의 경우 치료 후 1개월째, 2개월째, 4개월째 두 군 간 유의한 차이는 보이지 않았다(p>0.05). 결론: 3% 디쿠아포솔나트륨의 효능은 안구건조증 환자의 나이와 상관없이 임상적인 증상호전 및 객관적인 검사치의 개선을 나타내지만, 특히 60세 이전에서 눈물막파괴시간, 쉬르머 I 결과치가 유의하게 증가하는 것으로 나타났다. Purpose: The aim of this study was to evaluate the clinical effect of 3% diquafosol in dry eye patients aged around 60 years. Methods: In total, 68 patients with dry eye syndrome were divided by age into 2 groups, Group I (29 patients, 29 eyes) under the age of 60 years and Group II (39 patients, 39 eyes) over the age of 60 years. To evaluate the effectiveness of 3% diquafosol, we measured the tear film break-up time (tBUT), performed the Schirmer I test, and used the corneal staining score as an objective indicator and the ocular surface disease index (OSDI) score as a subjective indicator at initial visit, 1 month, 2 months, and 4 months. Results: Significant improvements in the tear film break-up time, Schirmer I test, and OSDI were observed at 1,2, and 4 months after treatment with 3% diquafosol tetrasodium in both dry eye groups, but significant difference in the corenal staining score were not observed (p > 0.05). There were statistically significant improvement between the 2 age groups in the tBUT at 1 month (p = 0.012), 2 months (p = 0.005), and 4 months (p = 0.005), and improvements in the Schirmer I test between the 2 age groups at 1 month (p = 0.015), 2 months (p = 0.005), and 4 months (p = 0.005) were also observed. But, there was no significant difference in the corneal staining score and OSDI score between the 2 groups at 1, 2, and 4 months (p > 0.05). Conclusions: Topical 3% diquafosol tetrasodium administration was shown to be an effective treatment to improve clinical symptoms and objective indicators in dry eye patients regardless of age, showing significant improvements in tBUT and the Schirmer I test under the age of 60.

장기간 경과에 따른 라식술 후 각막의 공초점현미경 증례 3

장수경(Soo Gyeong Jang),김호윤(Ho Yun Kim),박영민(Young Min Park),이종수(Jong Soo Lee) 대한검안학회 2015 Annals of optometry and contact lens Vol.14 No.4

Purpose: To report the confocal morphological changes in the cornea at least 12 months after laser in situ keratomileusis (LASIK) compared with normal cornea. Case summary: Confocal microscopy was used to obtain data from three cases of post- LASIK at least 12 months. We evaluated confocal morphological images of the activated keratocyte, scarring tissue, stromal folding in the corneal epithelium, Bowman’s layer, stromal cells (anterior, middle, posterior keratocyte) and endothelium. Case 1) At 12 months after LASIK, although scar tissue was not observed, active keratocyte and stromal folding due to stromal edema were noted. Case 2) At 24 months after LASIK, active keratocyte and scarring tissue were not found. However, regenerated nerve plexus in the subepithelial nerve fiber layers was crooked and the stromal folding due to stromal edema was observed. Case 3) At 36 months after LASIK, the corneal epithelium and wing cell were normal but stromal folding still remained. Conclusions: Active keratocyte and stromal folding were still noted at 12 months after LASIK. Especially, stromal folding due to stromal edema remained at 36 months after LASIK.

Three-Step Input Control Scheme for Minimization of Robot's Vibration

Wan-Shik Jang(장완식),Kyoung-Suk Kim(김경석),Ho-Yun Kim(김호윤) 한국공작기계학회 1997 한국공작기계학회지 Vol.6 No.4