• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.367-372
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• 2010

Purpose: The purpose of this study was to provide useful information for evaluating the sensory function of patients with strabismus by identifying the distribution of anomalous retinal correspondence (ARC) and normal retinal correspondence (NRC) by the degree of refractive errors and deviation angles. Methods: Objective refraction (AR/K, Cannon RK-F1, Japan) and subjective refraction tests were performed on 56 subjects (male: 26, female: 30) by an examiner; objective deviation angle was measured using synoptophore (OCULUS Synoptophore, Germany) with subject' eyes fully corrected for distance, and then subjective deviation angle was measured. Results: In all groups with refractive errors, the number of ARC was larger than that of NRC(67%). Particularly, it was largest in groups with myopia (71%), and in all groups, the number of UARC was larger than that of HARC. In groups with anisometropia, although the numbers of NRC and ARC were same, the number of UARC was larger than that of HARC as in other groups. In the distribution of NRC and ARC by deviation angle, the number of NRC was larger than that of ARC (46%) only at microstrabismus (0 ~ ${\pm}10{\triangle}$). Conclusions: Normal retinal correspondence were the most emmetropia in the retinal response were much higher than in the more hyperopia than the retinal correspondence were more myopia. In addition, the smaller the angle of retinal correspondence Normal over many, but overall, respectively.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.397-398
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• 2019

망막혈관 영상에서(retinal image) 혈관의 모양 또는 생성변화를 효과적으로 검진하기 위해서 망막혈관을 자동적으로 분리하는 영상분할 기법의 개발은 매우 중요한 사안이다. 이를 위해서 주로 망막혈관영상의 잡음을 억제하고 또한 혈관의 명암대비도(contrast)를 증가시키는 전처리 과정을 거쳐서 혈관의 국부적인 화소값의 변화, 방향성을 판별하여 혈관을 자동적으로 검출하는 방법들이 제시되어왔으며 최근에는 합성곱 신경망(CNN) 딥러닝 학습모델을 활용한 망막혈관 분리 알고리즘들이 제시되고 있다.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.211-217
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• 1992

망막분지정맥폐쇄는 안저출혈을 일으키는 중요한 질환의 하나로서 합병성 황반부 부종 및 망막신생혈관에 의한 초자체출혈로 인하여 시력장애를 유발하는 질환으로 전신질환중 고혈압과 가장 흔히 동반되나 당뇨병 혹은 혈액성 질환과도 동반되는 것으로 알려져있다. 초자체출혈의 경우 다른 원인에 의한 경우보다 초자체절제술에 의한 시력개선의 효과가 현저한 질환으로 심한 초자체출혈이 동반된 망막분지정맥폐쇄의 경우 평면부를 통한 초자체절제술 및 안저광응고술에 의한 수술적 처치가 필요할 것으로 사료된다.

• The Monthly Diabetes
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• s.151
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• pp.50-51
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• 2002

당뇨병성 막망증은 지속적인 고혈당과 이에 따른 대사이상으로 망막의 미세혈관이 점차 변형, 폐쇄되어 망막으로의 원활한 혈액공급이 되지 못하고 혈관투과성이 증가하여 망막에서 신생혈관이 생성되는 질환이다. 진행된 후에 치료를 통한 시력호전이 불가능하므로 조기진단 및 적절한 관리가 중요하나, 치료가 가능한 초기질환 외에 당뇨병성 망막증이 상당히 진행된 경우에도 주관적 증상이 없는 경우가 많다. 따라서 시력장애 등의 증상이 나타난 후에는 이러한 예방적인 조치를 취할 수 있는 시기를 지나치는 수가 많다.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.74-75
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• 2003

안구는 외막, 중막, 내막, 등으로 이루어져 있고, 그 중에서 가장 중요한 부분의 망막이다. 망막은 외부 물체에서 오는 빛을 받아 그 양을 정량적으로 분척하여 뇌로 보내는 역할을 한다. 이로 인해서 망막이 손상되면 눈에 치명적인 영향을 주어 자칫 시력을 잃을 수 있다. 안과에서 의사들은 정확한 병명을 진단하거나 안전한 수술을 하기 위해서 명확한 망막의 상을 얻어야 한다. 본 연구는 공초점 방식으로 망막 영상을 획득하기 위한 연구로써, 폴리곤 미터, 갈바노 미터 등의 복잡한 광학적 시스템이 제안되었다. (중략)

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.50-55
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• 2009

Purpose : This study aimed to determine the influence of low-dose oxygen ($FiO_2$ <25%) therapy through nasal cannulae on the progress and prognosis of retinopathy of prematurity (ROP) as well as methods of preventing ROP. Methods : Our subjects comprised premature infants (gestation period <37 weeks; birth weight <1,750 g) born in Daegu Fatima Hospital between February 1, 2001 and January 31, 2006. We retrospectively reviewed and analyzed the medical records of 273 patients who were available for eye examination and follow up over 6 months. Results : The factors maximally influencing the occurrence of ROP were low gestation age and low birth weight. We observed that the incidence of ROP increased with the increasing duration of low-dose oxygen therapy. ROP onset was delayed during ongoing oxygen therapy; however, rapid progression of ROP occurred after the discontinuation of oxygen therapy among premature infants up to the prethreshold stage. Conclusion : To prevent of occurrence of severe ROP and its rapid progression, the period of low-dose oxygen therapy needs to be shortened. Moreover, frequent eye examinations should be performed after the discontinuation of oxygen therapy.

• Progress in Medical Physics
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• v.17 no.4
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• pp.260-267
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• 2006

A retinal ganglion cell's receptive field is defined as that region on the retinal surface In which a light stimulus will produce a response. A retinal ganglion cell peers out at a small patch of the visual scene through its receptive field and encodes local features with action potentials that pass through the optic nerve to higher centers. Therefore, defining the receptive field of a retinal ganglion cell is essential to understand the electrical characteristics of a ganglion cell. Distribution of receptive fields over retinal surface provides us an Insight how the retinal ganglion cell processes the visual scene. In this paper, we provide the details how to reconstruct the receptive field of a retinal ganglion cell. We recorded the ganglion cell's action potential with multielectrode array when the random checkerboard stimulus was applied. After classifying the retinal waveform Into ON-cell, OFF-cell, ON/OFF-cell, we reconstructed the receptive field of retinal ganglion cell with Matlab. Here, we show the receptive fields of ON-cell and OFF-cell.

• Korean Journal of Veterinary Research
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• v.26 no.2
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• pp.221-224
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• 1986

Kainic acid가 오리 망막에 미치는 영향을 알아보기 위하여 kainic acid $50{\mu}l$($1.0{\mu}mol$)를 오리의 안구내로 주입한 후 망막을 경시적으로 관찰하였던 바 다음과 같은 결과를 얻었다. 주사후 8시간째 망막의 내내핵층과 내망상층에서 공포화가 인정되었고 24시간째는 내핵층에서 핵농축이 현저하였으며 48시간째의 예에서는 농축된 핵이 상당수 소실되면서 망막의 두께도 다소 얇게 나타났다. 주사후 96시간과 10일째는 내핵층을 구성하는 대부분의 세포가 소실되어 망막의 두께가 상당히 얇아졌고 내망상층의 두께도 경시적으로 얇아지는 경향이었다.

• Korean Journal of Cognitive Science
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• v.14 no.3
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• pp.1-11
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• 2003

Two experiments were conducted to investigate effects of target types and retinal eccentricity on the search of a target while both target and background stimuli were static or moving. A visual search task was used in both experiments. The retinal eccentricity was determined by five concentric circles increasing by the unit of 1.6 and the target was different from the background stimuli in either orientation(orientation target) or a distinctive feature(feature target). In Experiment 1 where both the target and background stimuli were presented statically, an interaction between retinal eccentricity arid target type was found. While search time of the orientation target was not affected by the retinal eccentricity, that of the feature target increased as the retinal eccentricity increased. In Experiment 2 where all stimuli were moving, the interaction effect was also found. But the reason was not the same as that in Experiment 1. In the moving condition, while the search time of the orientation target decreased consistently as the retinal eccentricity increased, that of the feature target was not affected by the retinal eccentricity. The implications and limitations of the present results were discussed with respects to the real world situations such as driving cars or flying airplanes.

• Journal of Yeungnam Medical Science
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• v.11 no.1
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• pp.153-159
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• 1994

Extracapsular cataract extraction with posterior chamber intraocular lens in 24 eyes of 24 diabetics, with and without diabetic retinopathy, were followed up postoperatively for an average of 14 months to determine the incidence of progression of diabetic retinopathy, the final visual acuity and factors predictive of progression of retinopathy and final visual acuity. Overall, retinopathy progressed in 52% of operated-on eyes. Cataract extraction was highly associated with progression of diabetic retinopathy. Women had a significantly increased risk of progression of retinopathy in the operated-on eye compared to men. Visual acuity improved in 22 of 24 orerated-on eyes : however, only 11 eyes achieved a visual acuity of 0.5 or better and only 7 eyes achieved a visual acuity of 0.7 or better. Patients treated with oral hypoglycemic agents had a worse visual prognosis than those treated with insulin. The prognosis of patients with diabetic retinopathy about to undergo cataract surgery, even extracapsular cataract extraction with placement of a posterior chamber lens, is guarded.