• BMB Reports
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• 제48권4호
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• pp.193-199
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• 2015

Degenerative retinal diseases affect millions of people worldwide, which can lead to the loss of vision. However, therapeutic approaches that can reverse this process are limited. Recent efforts have allowed the possibility of the stem cell-based regeneration of retinal cells and repair of injured retinal tissues. Although the direct differentiation of pluripotent stem cells into terminally differentiated photoreceptor cells comprises one approach, a series of studies revealed the intrinsic regenerative potential of the retina using endogenous retinal stem cells. Muller glial cells, ciliary pigment epithelial cells, and retinal pigment epithelial cells are candidates for such retinal stem cells that can differentiate into multiple types of retinal cells and be integrated into injured or developing retina. In this review, we explore our current understanding of the cellular identity of these candidate retinal stem cells and their therapeutic potential for cell therapy against degenerative retinal diseases. [BMB Reports 2015; 48(4): 193-199]

• International Journal of Stem Cells
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• 제17권2호
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• pp.204-211
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• 2024

With recent advances in adeno-associated virus (AAV)-based gene therapy, efficacy and toxicity screening have become essential for developing gene therapeutic drugs for retinal diseases. Retinal organoids from human pluripotent stem cells (hPSCs) offer a more accessible and reproducible human test platform for evaluating AAV-based gene therapy. In this study, hPSCs were differentiated into retinal organoids composed of various types of retinal cells. The transduction efficiencies of AAV2 and AAV8, which are widely used in clinical trials of inherited retinal diseases, were analyzed using retinal organoids. These results suggest that retinal organoids derived from hPSCs serve as suitable screening platforms owing to their diverse retinal cell types and similarity to the human retina. In summary, we propose an optimal stepwise protocol that includes the generation of retinal organoids and analysis of AAV transduction efficacy, providing a comprehensive approach for evaluating AAV-based gene therapy for retinal diseases.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.614-616
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• 2021

세계는 안구 질병 치료, 시력 회복 서비스, 훈련된 안과 전문의의 부족 등 안과 측면에서 어려움에 직면해 있다. 안구 병리를 조기에 발견하고 진단하면 시각 장애를 예방할 수 있다. 하지만 기존의 망막 영상 공개 데이터 세트는 임상에서 발견되는 다양한 질병으로 구성되어 있지 않기 때문에 다양한 안구 질환을 분류하는 방법을 개발하기가 어렵다. 본 연구는 2021 ISBI challenge에서 공개된 데이터 세트인 Retinal Fundus Multi-disease Image Dataset (RFMiD) 을 이용하여 안구 질환을 분류하는 방법을 제안한다. 본 연구의 목표는 망막 이미지를 정상, 비정상 범주로 선별하기 위한 강력하고 일반화 가능한 모델을 개발하는 것이다. 제안된 모델의 성능은 수신자 조작 특성 곡선 아래 면적 점수로 비공개 테스트 데이터 세트에 대해 0.9782의 값을 보여준다.

• 한국임상수의학회지
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• 제18권3호
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• pp.215-225
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• 2001

This study presented the results of ophthalmic examinations performed on 545 Korean Jindo dogs. The most prevalent ocular variation within normal limits was hyoid vessel remnant (12.7%) and prominence of lens suture was also noticed (1.7%). The most common ocular diseases were retinal scars (6.8%), focal cataract (4.6%) and persistent pupillary membrane (4.2%). Inherited ocular diseases found in this study were persistent pupillary membrane (4.2%), persistent hyperplastic primary vitreous (0.6%), retinal dysplasia (0.6%), entropion (0.4%) and progressive retinal atrophy (0.4%). The prevalence of ocular diseases was higher in Male than in Female and proportionately higher in the older dogs. The most prevalence was shown in white coat color dogs. The fundus color changes according to the age was not related in coat colors and shown same pattern.

• 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.

• 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.

• Advances in nano research
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• 제13권1호
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• pp.87-96
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• 2022

Drug self-delivery systems can easily realize combination drug therapy and avoid carrier-induced toxicity and immunogenicity because they do not need non-therapeutic carrier materials. So, designing appropriate drug self-delivery systems for specific diseases can settle most of the problems existing in traditional drug delivery systems. Retinal pigment epithelium is very important for the homeostasis of retina. However, it is vulnerable to oxidative damage and difficult to repair. Worse still, the antioxidants can hardly reach the retina by non-invasive administration routes due to the ocular barriers. Herein, the targeted group (folic acid) and antioxidant (melatonin) have been grafted on the surface of ZnO quantum dots to fabricate a new kind of drug self-delivery systems as a protectant via eyedrops. In this study, the negative nanoparticles with size ranging in 4~6 nm were successfully synthesized. They could easily and precisely deliver drugs to retinal pigment epithelium via eyedrops. And they realized acid degradation to controlled release of melatonin and zinc in retinal pigment epithelium cells. Consequently, the structure of retinal pigment epithelium cells were stabilized according to the expression of ZO-1 and β-catenin. Moreover, the antioxidant capacity of retinal pigment epithelium were enhanced both in health mice and photic injury mice. Therefore, such new drug self-delivery systems have great potential both in prevention and treatment of oxidative damage induced retinal 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.

• 대한수의학회지
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• 제41권1호
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• pp.113-121
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• 2001

Beagle is one of the most popular laboratory animal in a dog. We investigated the incidence of spontaneous ophthalmic disease in Beagles in order to make basic data for quality control of Beagles in Korea. We surveyed 389 beagles from 3 different farms. The average prevalence rate of ophthalmic diseases was 19.3%. The prevalence rate of cataracts was higher than any other ophthalmic diseases, 7.5% and then in order of corneal scar(2.1%), retinal hemorrhage(1.5%), post-inflammatory retinal change(1.5%), cherry eye(1.0%), distichiasis(0.8%), entropion(0.8%), hypoplastic optic disc(0.8%), conjunctivitis(0.5%), retinal dysplasia(0.5%), asteroid hyalosis(0.3%), congenital eye anomaly(0.3%), corneal lipidosis(0.3%), conjunctival hemorrhage(0.3%), lens capsule pigmentation(0.3%), persistent hyperplastic primary vitreous (0.3%), posterior synechia(0.3%), eyelid tumor(0.3%) and uveal cyst(0.3%) were diagnosed. There was a slight difference between male(24.8%) and female(17.4%) in prevalence rate of ophthalmic disease. The incidence of spontaneous ophthalmic disease was increased with age. These data would be useful for using Beagles as laboratory animals and standard reference for quality control of dogs.

• 한국임상수의학회지
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• 제32권3호
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• pp.235-238
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• 2015

서울에서 개의 안과질환에 대한 역학적인 특징에 대해 2009년 1월부터 2013년 12월까지우성동물메디칼센터에 안과질환으로 내원한 초진환자들의 자료를 분석하였다. 총 1253두의 안과환자들이 초진 내원하였으며, 평균나이는 7.93년령 (SD, 4.06)이었다. 환자중에 Shih Tzu (29.4%)가 가장 많았으며, Maltese, Yorkshire Terrier, Cocker Spaniel, toy Poodle (P < 0.01)이 뒤를 따랐다. 눈에서 질병이 호발하는 곳은 수정체 관련 질환이 가장 많았으며 (28.3%), 안검질환, 망막질환, 비루관질환, 포도막질환, 유리체질환, 시신경계 질환이 그 뒤를 따랐다(P < 0.01). 수정체, 안검, 망막, 비루관, 포도막, 유리체, 시신경계 질환들은 주로 양측성 질환(P < 0.01)으로 발생하는 경향을 보였다. Shih Tzu에서는 각막질환이 가장 많이 발생하였으며, 수정체, 안검, 망막, 녹내장 질환이 그 뒤를 따랐다. Maltese에서는 수정체, 안검, 망막, 각막질환의 순으로 질병이 발생했다. Yorkshire Terrier, Cocker Spaniel, 그리고 toy Poodle 종은 수정체 질환이 가장 많았다(P < 0.01). 안과질환으로 병원에 내원하는 주된 환자들은 Shih Tzu, Maltese, Yorkshire Terrier등과 같은 소형견들이었고, 대부분 수정체 질환과 같은 품종소인이 있는 질환이 대부분이었다.