• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2022년도 추계학술발표대회
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• pp.43-45
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• 2022

본 논문은 황반변성 진단 모델 개발을 위해 안저 사진을 이용한 MobileNet2 전이학습 모델 개발과 안정적인 모델 성능을 위한 이미지 증강 방법 및 모델 성능 향상을 위한 파라미터 조정 방법을 제안한다. 보유하고 있는 이미지의 수가 매우 적다고 하더라도 적절한 전이학습 모델을 사용하고 이미지 증강 시 증강 방법과 증강한 이미지와 정상 이미지와의 비율을 적절히 고려할 경우 충분히 안정적인 결과를 얻어낼 수 있다. 또한 파라미터 조정을 통해서 성능 향상을 도모할 수 있다

• 대한안과학회지
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• 제59권12호
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• pp.1142-1151
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• 2018

목적: 삼출 나이관련황반변성에 대한 유리체내 항혈관내피성장인자 주사 치료의 장기 결과를 알아보고자 한다. 대상과 방법: 삼출 나이관련황반변성 진단 후 treat-and-extend 또는 as needed 방법으로 7년 이상 유리체내 항혈관내피성장인자 주사 치료를 시행 받은 환자들에 대한 후향적 의무기록 분석을 시행하였다. 주사 횟수, 최대교정시력 및 중심망막두께 등을 평가하였으며, 장기간 주사 치료에 따른 부작용 여부를 같이 조사하였다. 결과: 총 196명의 196안을 분석하였다(평균 나이 $68.6{\pm}9.6$세, 여성 77명). 평균 $78.0{\pm}16.5$개월 경과관찰하였고, 해당 기간 동안 평균 $17.3{\pm}13.5$회의 유리체내주사가 시행되었다. 치료 전 측정한 최대교정시력은 평균 $0.75{\pm}0.58$ logMAR, 중심망막두께는 $349.7{\pm}152.6{\mu}m$였고, 6개월째 두 수치 모두 최대 호전을 보였으나(p<0.05), 이후 점차 악화 소견을 보이며 7년째 최대교정시력 $0.91{\pm}0.78$ logMAR, 중심망막두께 $284.5{\pm}105.8{\mu}m$로 확인되었다. 주사 후 7년째 시력은 치료 전 시력과 강한 양의 상관관계를 보였다. 장기간 주사 동안 총 11회의 안압상승 및 3회의 전방 내 염증 증가 소견이 있었으나 안내염 등의 심각한 부작용은 관찰되지 않았다. 결론: 삼출 나이관련황반변성에서 유리체내 항혈관내피성장인자 주사 치료 후 초기 6개월간의 최대 시력 호전이 있었으나 5년 이상 경과 시 지속적인 시력 저하를 막지 못하였다. 진단 당시 시력이 장기 시력예후와 관련된 중요 예측 인자로 판단되며 적극적인 유리체 내주사 치료를 통해 더 나은 장기 시력 결과를 기대해 볼 수 있다.

• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.1024-1030
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• 2007

We investigated the human apolipoprotein E2 (apoE2) transgenic mouse as an animal model system for age-related macular degeneration (AMD). Transgenic mice expressing human apoE2 and C57BL/6J mice were fed normal chow or a high-fat diet for 4 weeks. Eyes were collected from the mice and lipid deposits in retinal pigment epithelium (RPE) were assessed using electron microscopy. The expressions of apoE, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and pigment-epithelium derived factor (PEDF), which are molecular markers for angiogenesis, were assessed with immunohistochemistry. Eyes from apoE2 mice, regardless of diet, contained lipid accumulation in RPE under electron microscopy, whereas control C57BL/6J eyes did not. Lipid accumulation was found predominantly in the RPE and the Bruch's membrane and increased in the eyes of apoE2 mice after one month of a high-fat diet ($8{\pm}2\;per\;50{\mu}m^2$ for normal chow and $11{\pm}2\;per\;50\;{\mu}m^2,\;p<0.05)$. ApoE expression was similar in the apoE2 and control mice; however, VEGF and bFGF were overexpressed in the retinal pigment epithelium of apoE2 eyes compared with control eyes, and PEDF expression was slightly decreased. These expression patterns of VEGF, bFGF, and PEDF suggest angiogenesis is progressing in apoE2 eyes. In conclusion, the eyes of apoE2 mice develop typical lipid accumulations, a common characteristic of AMD, making them a suitable animal model for AMD. The expression profile of VEGF and bFGF on the retinal pigment epithelium suggests that apoE2 may induce neovascularization by altering angiogenic cytokines.

• 대한영양사협회학술지
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• 제27권2호
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• pp.77-91
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• 2021

This study was conducted to investigate the effect of the differences in nutrient intakes on the onset of eye disease in the ophthalmic disease group vs. the normal group. The analysis method of this study was performed by adjusting age and gender. The daily caloric intake was 1,672.1±26.4 kcal in the ophthalmic disease group which was significantly lower than the 2,041.5±13.6 kcal intake in the normal group (P=0.006). The intake of proteins (P=0.015) and carbohydrates (P=0.000) was significantly lower in the ophthalmic disease group than in the normal group. The incidence of eye diseases was found to decrease by about 0.79 (95% CI: 0.74~0.83) times as the NAR index of protein was increased, followed by 0.79 (95% CI: 0.64~0.98) times with an increase in niacin consumption. In this study, income, BMI, smoking, alcohol consumption, and quality of life were considered as the confounding variables related to eye disease, along with age and gender, but did not lead to show significant results. It was found that the ophthalmic disease group had an unbalanced nutritional intake compared to the normal group. Therefore, we conclude that nutrition education is necessary to ensurebalanced eating habits for management and prevention of degeneration after the onset of eye diseases.

• BMB Reports
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• 제51권7호
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• pp.315-316
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• 2018

Genome engineering with clustered regularly interspaced short palindromic repeats (CRISPR) system can be used as a tool to correct pathological mutations or modulate gene expression levels associated with pathogenesis of human diseases. Owing to well-established local administration methods including intravitreal and subretinal injection, it is relatively easy to administer therapeutic genome engineering machinery to ocular tissues for treating retinal diseases. In this context, we have investigated the potential of in vivo genome engineering as a therapeutic approach in the form of ribonucleoprotein or CRISPR packaged in viral vectors. Major issues in therapeutic application of genome engineering include specificity and efficacy according to types of CRISPR system. In addition to previous platforms based on ribonucleoprotein and CRISPR-associated protein 9 derived from Campylobacter jejuni, we evaluated the therapeutic effects of a CRISPR RNA-guided endonuclease derived from Lachnospiraceae bacterium ND2006 (LbCpf1) in regulating pathological angiogenesis in an animal model of wet-type age-related macular degeneration. LbCpf1 targeting Vegfa or Hif1a effectively disrupted the expression of genes in ocular tissues, resulting in suppression of choroidal neovascularization. It was also notable that there were no significant off-target effects in vivo.

• 한국멀티미디어학회논문지
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• 제22권11호
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• pp.1269-1279
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• 2019

In medical image analysis, segmentation is considered as a vital process since it partitions an image into coherent parts and extracts interesting objects from the image. In this paper, we consider automatic segmentations of OCT retinal images to find six layer boundaries using convolutional neural networks. Segmenting retinal images by layer boundaries is very important in diagnosing and predicting progress of eye diseases including diabetic retinopathy, glaucoma, and AMD (age-related macular degeneration). We applied well-known CNN architecture for general image segmentation, called Segnet, U-net, and CNN-S into this problem. We also proposed a shortest path-based algorithm for finding the layer boundaries from the outputs of Segnet and U-net. We analysed their performance on public OCT image data set. The experimental results show that the Segnet combined with the proposed shortest path-based boundary finding algorithm outperforms other two networks.

• The Korean Journal of Physiology and Pharmacology
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• 제12권6호
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• pp.307-314
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• 2008

Retinal prostheses are being developed to restore vision for the blind with retinal diseases such as retinitis pigmentosa (RP) or age-related macular degeneration (AMD). Among the many issues for prosthesis development, stimulation encoding strategy is one of the most essential electrophysiological issues. The more we understand the retinal circuitry how it encodes and processes visual information, the greater it could help decide stimulation encoding strategy for retinal prosthesis. Therefore, we examined how retinal ganglion cells (RGCs) in in-vitro retinal preparation act together to encode a visual scene with multielectrode array (MEA). Simultaneous recording of many RGCs with MEA showed that nearby neurons often fired synchronously, with spike delays mostly within 1 ms range. This synchronized firing - narrow correlation - was blocked by gap junction blocker, heptanol, but not by glutamatergic synapse blocker, kynurenic acid. By tracking down all the RGC pairs which showed narrow correlation, we could harvest 40 functional connectivity maps of RGCs which showed the cell cluster firing together. We suggest that finding functional connectivity map would be useful in stimulation encoding strategy for the retinal prosthesis since stimulating the cluster of RGCs would be more efficient than separately stimulating each individual RGC.

• 사상체질의학회지
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• 제30권3호
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• pp.1-24
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• 2018

Objective This study was aimed to provide the information about Cheongsimyeonja-tang by domestic papers and theses. Method 50 Domestic papers related to Cheongsimyeonja-tang were selected according to the criteria. These papers were classified and analyzed by research designs, methods and results. Result The following results were obtained in this study. 1. 19 experimental studies on the effect of Cheongsimyeonja-tang were mainly focused on anti-aging, followed by anti-allergy, anti-inflammation, improvement of immune system. And there were 4 experimental studies on the safety of Cheongsimyeonja-tang, proving safety by acute toxicity test, nephrotoxicity test, drug interaction, and test of residual ingredients after decoction. 2. 25 clinical studies on the effect of Cheongsimyeonja-tang were mainly focused on cardiovascular and cerebral vascular diseases, followed by psychiatric and otologic disorder, dermatologic and musculoskeletal diseases. Also, there were 2 studies on the effect of Cheongsimyeonja-tang for diabetes insipidus, macular degeneration, digestive disorder in terminal cancer, drug-induced hepatitis. 3. More evidenced studies on Cheongsimyeonja-tang are needed and it is recommended that psychiatric questionnaire should be used for assessing the effects of Cheongsimyeonja-tang.

• Design & Manufacturing
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• 제17권1호
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• pp.40-47
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• 2023

Macular degeneration and glaucoma are representative age-related retinal diseases that rank second and third in the prevalence of retinal diseases, and are a kind of degenerative neurological disease. Irreversible visual acuity and visual field damage may occur, and the number of patients is rapidly increasing as the population ages. Since this retinal disease is a chronic disease, continuous drug treatment is required. There are various drug delivery methods for treatment, but direct injection of the drug into the intravitreal is the most effective for continuous delivery of the drug over a long period of time. In order to solidify Dexamethasone, a retinal disease treatment, and insert it into the primary intravitreal, it is important to develop a technology to miniaturize the treatment and an applicator to deliver the treatment. In this study, a mold technology was developed to integrate the cannula and hub, which are one part of applicator. In addition, surface treatment was performed on the outside of the cannula to improve the bonding strength between the cannula and the hub, and the bonding strength according to each condition was analyzed through a tensile test.

• 한국안광학회지
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• 제17권1호
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• pp.91-97
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• 2012

목적: 본 연구는 노인성 황반변성(age-related macular degeneration, AMD)의 병인으로 잘 알려진 A2E의 광산화가 자외선 차단렌즈나 brown 착색렌즈에 의해 억제되는가를 알아보고자 하였다. 방법: 두 분자의 all-trans-retinal과 한 분자의 ethanolamine을 합성하여 만든 A2E에 청색광(420~470 nm, $94mW/cm^2$)을 3분 동안 조사하여 광산화를 유도하였다. UV 차단 및 brown 착색 안경렌즈의 A2E의 광산화 저해 효과는 광산화되지 않고 남아있는 A2E의 흡광도와 HPLC chromatogram 분석을 통하여 확인하였다. 결과: 자외선 차단렌즈는 청색광 조사로 유발되는 A2E의 광산화를 억제하지 못하였다. 반면 Brown 착색렌즈에서는 가시광선 차단율이 15%인 경우 A2E의 광산화율에는 별차이가 없었지만, 55%와 86% 차단된 렌즈에서는 각각 9.98%, 16.55%의 A2E 광산화 억제 효과를 보였다. HPLC로 분석한 잔존 A2E량을 확인해 보면 렌즈로 차단하지 않은 A2E의 잔존량은 $199.29{\pm}26.53{\mu}M$ 이었으나, 55% 차단율을 가진 brown 렌즈는 $264.58{\pm}31.91{\mu}M$, 86% 차단율을 가진 렌즈에서는 $402.93{\pm}26.68{\mu}M$의 A2E 잔존량을 보여 A2E 광산화 억제효과가 있음을 확인하였다. 반면, 자외선 차단렌즈의 경우에는 잔존량 분석에서도 광산화 억제효과가 없는 것으로 나타났다. 결론: 본 연구결과를 통하여 brown 착색 안경렌즈는 노인성 황반변성의 원인물질인 A2E의 광산화를 억제하는 효과가 있는 것으로 알 수 있었다.