• BMB Reports
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• v.48 no.4
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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]

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.614-616
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• 2021

The world faces difficulties in terms of eye care, including treatment, quality of prevention, vision rehabilitation services, and scarcity of trained eye care experts. However, it is difficult to develop a method for classifying various ocular diseases because the existing dataset for retinal image disclosure does not consist of various diseases found in clinical practice. We propose a method for classifying ocular diseases using the Retinal Fundus Multi-disease Image Dataset (RFMiD), a dataset published in the ISBI-2021 challenge. Our goal is to develop a robust and generalizable model for screening retinal images into normal and abnormal categories. The performance of the proposed model shows a value of 0.9782 for the test dataset as an area under the curve (AUC) score.

• Journal of Veterinary Clinics
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• v.18 no.3
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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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• v.17 no.1
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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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• v.12 no.6
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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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• v.13 no.1
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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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• v.51 no.7
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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.

• Korean Journal of Veterinary Research
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• v.41 no.1
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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.

• Journal of Veterinary Clinics
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• v.32 no.3
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• pp.235-238
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• 2015

This study aimed to investigate the epidemiology of canine ophthalmic diseases in Seoul, Korea using data for new canine patients examined from January 2009 through December 2013 at an ophthalmic referral center (WooSung Animal Medical Center, Seoul). The study included 1253 dogs with an average age of 7.93 years (SD, 4.06). Shih Tzu (29.4%) was the most common breed, followed by Maltese, Yorkshire Terrier, Cocker Spaniel, and toy Poodle (P < 0.01). Lens diseases (28.3%) were the most common, followed by eyelid, corneal, retinal, and glaucomatous diseases (P < 0.01). Lens, eyelid, retinal, nasolacrimal, uveal, vitreous, and neuro-ophthalmic diseases more frequently showed a bilateral occurrence (P < 0.01) than a unilateral occurrence. In the Shih Tzu breed, corneal disease was the most frequent, followed by lens, eyelid, retinal, and glaucomatous diseases. The most frequent diseases in the Maltese breed were lens, eyelid, retinal, and corneal diseases. In the Yorkshire Terrier, Cocker Spaniel, and toy Poodle breeds, lens disease was the most common (P < 0.01). The most frequent ophthalmic patients belonged to small breeds such as Shih Tzu, Maltese, and Yorkshire Terrier. Moreover, the most common ophthalmic diseases were not traumatic diseases, but breed-inherited diseases such as lens diseases.

• Journal of Korean Clinical Nursing Research
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• v.27 no.1
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• pp.54-65
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• 2021

Purpose: The purpose of this study was to identify influencing factors on vision-related quality of life in patients with retinal diseases receiving intravitreal injections by examining relationships among anxiety, depression, coping, eye health behaviors and vision-related quality of life. Methods: One hundred and five outpatients who were diagnosed with macular degeneration and diabetic retinopathy were recruited from one university hospital during August 16, 2019 to March 25, 2020. Data were analyzed using descriptive statistics (frequency and percentage, mean, standard deviation), and t-tests, ANOVA, Scheffé test, Pearson's correlations, and stepwise multiple regressions using the IBM SPSS Statistics 25.0. Results: The vision-related quality of life according to general characteristics of retinal disease patients with intravitreal injection showed significant differences in age (F=3.01, p=.034), subjective economic status (F=5.83, p=.004), types of retinal disease (t=2.62, p=.010), and disease in both eyes (t=-3.04, p=.003). The vision-related quality of life showed a significant positive correlation with age (r=.24, p=.012), and negative correlations with anxiety (r=-.66, p<.001), depression (r=-.48, p<.001), and emotion-focused coping (r=-.20, p=.036). The hierarchical regression analysis indicated that factors affecting vision-related quality of life in patients with retinal diseases were anxiety and subjective economic status, accounting for 47.0% of the variances of the vision-related quality of life. Conclusion: Based on our results, health professionals need to pay attention to patients with low socioeconomic status due to frequent treatments. Also, a program needs to be developed to decrease anxiety for outpatients receiving intravitreal injections to improve their vision-related quality of life.