• Journal of Yeungnam Medical Science
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• v.24 no.2
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• pp.243-251
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• 2007

Purpose : This study was conducted to assess the surgical outcomes of limbal lensectomy with or without anterior vitrectomy for the management of lens subluxation. Materials and Methods : The medical records of 20 consecutive patients (33 eyes) with lens subluxation who had undergone limbal lensectomy with or without anterior vitrectomy from February 1999 to January 2004 were retrospectively reviewed. Results : All the patients, except one high axial myopic patient, were implanted with scleral sutured posterior chamber intraocular lens. We evaluated the preoperative, postoperative visual acuity and postoperative complications and compared the results in group I (limbal lensectomy with anterior vitrectomy, 27 eyes) to those in group II (limbal lensectomy without anterior vitrectomy, 6 eyes). The preoperative best-corrected visual acuity was 0.21 and postoperative best-corrected visual acuity was improved by 2 lines or more in all 27 eyes in group I, and in 5 eyes in group II (p>0.05). The most frequent postoperative complication was intraocular lens dislocation in four eyes (14.8%) in group I alone. No retinal detachment occurred in either group, even in patients with high myopia. Conclusion : Limbal lensectomy without anterior vitrectomy improved visual acuity similarly to limbal lensectomy with anterior vitrectomy without significant increase of postoperative complications. This results of this study suggest that anterior vitrectomy is not necessarily required for the management of lens subluxation.

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.163-166
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• 2010

Purpose : Leigh syndrome is a typical type of mitochondrial disease. This study was conducted to analyze the types of ophthalmologic symptoms and results of funduscopy conducted in the ophthalmologic examination of patients with Leigh syndrome. Methods : Funduscopy was conducted on 24 subjects, who were chosen among those diagnosed as having mitochondrial respiratory chain complex defect and who were clinically suitable for the criteria of Leigh syndrome. Their clinical features, ophthalmologic symptoms, and ophthalmologic examination results were retrospectively analyzed. Results : Of the 24 patients with Leigh syndrome, 11 developed ophthalmologic symptoms and no abnormal finding was observed in 13. The most frequent abnormal finding was visual disturbance in 5 patients. Funduscopy revealed abnormal findings in 17 patients; retinal pigmentation was the most frequent abnormality and was seen in 9 patients. Conclusion : Funduscopy can be an important screening test to find ophthalmologic abnormalities among patients with mitochondrial disease (MD), including those patients whose ophthalmologic symptoms are inconspicuous. It is predicted that an improved screening test can be made in the future that will identify risk factors related to ophthalmologic symptoms.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.1
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• pp.99-104
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• 2014

Purpose: This study was to investigate the functional improvement in peripheral vision following eccentric viewing training. Methods: 14 subjects with normal vision took a part with their right eye, peripheral retinal which is $20^{\circ}$ lateral area from the fovea was examined for contrast sensitivity(CS). Eccentric viewing training was performed for 21days with an hour image viewing and examination was repeated. Results: The critical durations for 0.7 cpd were increased 2.67(467 ms) for pre-eccentric viewing training to 2.79(616 ms) for post-eccentric viewing training (p>0.05). The critical durations for 3.0 cpd were also increased 2.53(341 ms) for pre-eccentric viewing training to 3.04(1102 ms) for post-eccentric viewing training (p>0.05). Conclusions: It is recommended to use higher spatial frequency with higher CS for eccentric viewing training and to train more frequently for a short time. Moreover, the study on Korean standardizing of the visual rehabilitation for low vision based on the etiology is sorely required.

• Journal of Life Science
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• v.23 no.8
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• pp.1064-1072
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• 2013

Circadian rhythm is controlled by hormonal oscillations governing the physiology of all living organisms. In mammals, the main function of the pineal gland is to transform the circadian rhythm generated in the hypothalamic suprachiasmatic nucleus into rhythmic signals of circulating melatonin characterized by a largely nocturnal increase that closely reflects the duration of night time. The pineal gland has lost direct photosensitivity, but responds to light via multi-synaptic pathways that include a subset of retinal ganglion cells. Rhythmic control is achieved through a tight coupling between environmental lighting and arylalkylamine-N-acetyltransferase (AANAT) expression, which is the rhythm-controlling enzyme in melatonin synthesis. Previous studies on the nocturnal expression of AANAT protein have described transcriptional, post-transcriptional, and post-translational regulatory mechanisms. Molecular mechanisms for dependent AANAT expression provide novel aspects for melatonin's circadian rhythmicity. Extensive animal research has linked pineal melatonin for the expression of seasonal rhythmicity in many mammalian species to the modulation of circadian rhythms and to sleep regulation. It has value in treating various circadian rhythm disorders, such as jet lag or shift-work sleep disorders. Melatonin, also, in a broad range of effects with a significant regulation influences many of the body's physiological functions. In addition, this hormone is known to influence reproductive, cardiovascular, and immunological regulation as well as psychiatric disorders.

• Applied Microscopy
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• v.37 no.1
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• pp.35-42
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• 2007

The late pupal stage of Drosophila melanogaster occurs immediately before the completion of retinal development, during which the rhabdomere rapidly forms. In this period, the photoreceptor cells were fixed and dehydrated using a high-pressure freezer (HPF) and freeze substitution (FS) technique, which is the most effective in preserving the cell structures, and observed using high-voltage electron microscopy (HVEM) at 1000 KV. The rhabdomere was classified structurally into three types of formation patterns using stereo-tiling image of thick sections. Initially, hexagonal arrays of rhabdomere existed in different angles. In addition, small pieces of rhabdomere could be observed in the cytoplasm of the photoreceptor rolls, which were visible during the profess of rhabdomere formation. In addition, multiple layers of rhabdomere strings were observed. We observed there are at least three types of vesicles related to rhabdomere formation in photoreceptor cells. In addition, it was found that these vesicles initiate the formation of the rhabdomeres during the pupal stage. Collectively, these data suggest that rhabdomeres were mainly formed through vesicles, and that parts of the rhabdomere formed first and then gathered and formed rhabdomeres in the late pupal stage.

• Journal of Veterinary Clinics
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• v.25 no.6
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• pp.482-487
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• 2008

This study was performed to investigate the ophthalmic findings of the Korean traditional 'Sapsaree' dogs, and to provide ophthalmic references. Five hundred forty-seven Sapsaree dogs were randomly chosen without any criteria preference. Ophthalmic examination was performed bilaterally using ocular equipments, including slit-lamp biomicroscope, tonometer, direct and indirect ophthalmoscope. The obtained data for ophthalmic findings were analysis by the multivariate linear regression model to identify effects of sex, age and hair coat type. For congenital conditions, the incidence of persistent pupillary membrane (PPM) was the most common defect and there was present 8.8 % whereas for acquired ophthalmic diseases, cataract was the most commonly observed (3.7 %) in Sapsaree dog. Other frequent ocular finding included persistent hyaloid vessel remnant (PHVR, 6.2 %) in congenital conditions, and postinflammatory retinal degeneration (PIRD, 3.1 %) and corneal dystrophy (2.4 %) in acquired ophthalmic diseases. Only one significant effect was age of the Sapsaree for PIRD (P=0.040). There are no any significant effect for sex and hair coat types. This study will provide useful guidelines to clinicians and breeders for the basic ophthalmic information on this breed.

• Journal of The Korean Ophthalmological Society
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• v.59 no.11
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• pp.1062-1070
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• 2018

Purpose: We evaluated the prognostic factors of open globe injuries in children and adolescents, and compared the ocular trauma score (OTS) and pediatric penetrating ocular trauma score (POTS). Methods: We performed a retrospective review of 77 children under 18 years of age who visited our clinic with open globe injuries between May 1993 and April 2014. We investigated the factors that may affect final visual acuity. We also compared the OTS and POTS using receiver operating characteristic curves as a method to predict final visual acuity. Results: By univariate analysis, an initial visual acuity less than 20/200, globe rupture, wound size greater than 7.0 mm, retinal detachment, lens dislocation, and total number of operations contributed to worse visual outcomes (<20/200). Conversely, central corneal involvement, traumatic cataract, wound size less than 7.0 mm, and initial visual acuity greater than 20/200 were better prognostic indicators (${\geq}20/32$). Both OTS and POTS had diagnostic value as a predictor of final visual acuity, although there were no statistically significant differences between the two scoring systems. Conclusions: Initial visual acuity and wound size are important prognostic factors for the final visual acuity in children and adolescent, following open globe injuries. Both OTS and POTS are reliable prognostic models for open globe injuries in children and adolescents.

• Journal of The Korean Ophthalmological Society
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• v.59 no.11
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• pp.1097-1102
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• 2018

Purpose: To report a case of toxic optic neuropathy caused by chlorfenapyr ingestion accompanied by central nervous system involvement. Case summary: A 44-year-old female visited our clinic complaining of reduced visual acuity in both eyes for 7 days. She had ingested a mouthful of chlorfenapyr for a suicide attempt 2 weeks prior to the visit. Gastric lavage was performed immediately after ingestion at the other hospital. Her best-corrected visual acuity was finger count 30 cm in the right eye and hand motion in the left eye. Both pupils were dilated by 5.0 mm and the response to light was sluggish in both eyes. A relative afferent pupillary defect was detected in her left eye. Funduscopy revealed optic disc swelling in both eyes. Magnetic resonance imaging of the brain showed a symmetric hyper-intense signal in the white matter tract including the internal capsule, corpus callosum, middle cerebellar peduncle, and brainstem. The patient was diagnosed with toxic optic neuropathy induced by chlorfenapyr ingestion, and underwent high-dose intravenous corticosteroid pulse therapy. Three days later, the best-corrected visual acuity was no light perception in both eyes. Three months later, optic atrophy was observed in both eyes. Optical coherence tomography revealed a reduction in the thicknesses of the retinal nerve fiber layer and ganglion cell and inner plexiform layer in the macular area. Conclusions: Ingestion of even a small amount of chlorfenapyr can cause severe optic nerve damage through the latent period, despite prompt lavage and high-dose steroid treatment.

• The Journal of Bigdata
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• v.6 no.1
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• pp.37-49
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• 2021

The number of dementia patients in Korea is estimated to be over 800,000, and the severity of dementia is becoming a social problem. However, no treatment or drug has yet been developed to cure dementia worldwide. The number of dementia patients is expected to increase further due to the rapid aging of the population. Currently, early detection of dementia and delaying the course of dementia symptoms is the best alternative. This study presented a methodology for early diagnosis of dementia by measuring and analyzing amyloid plaques. This vital protein can most clearly and early diagnose dementia in the retina through AI-based image analysis. We performed binary classification and multi-classification learning based on CNN on retina data. We also developed a deep learning algorithm that can diagnose dementia early based on pre-processed retinal data. Accuracy and recall of the deep learning model were verified, and as a result of the verification, and derived results that satisfy both recall and accuracy. In the future, we plan to continue the study based on clinical data of actual dementia patients, and the results of this study are expected to solve the dementia problem.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.3
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• pp.266-276
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• 2021

Fundus hemorrhage refers to abnormalities in the retinal tissue and blood vessels. Therefore, when a hemorrhagic change in the fundus occurs, the ophthalmologist orders various ophthalmic tests to evaluate the degree of hemorrhage and determine the progress of the lesion before, during, and after treatment to accordingly establish a treatment plan. Currently, the most useful and universal fundus examination includes optical coherence tomography (OCT), fundus photography (FP), and fluorescein angiography (FAG). Existing fluorescein angiography test methods for establishing a treatment plan for severe fundus bleeding have limitations. The authors propose that peripheral pupil and the 5-quadrant method should be performed using ultra-wide-angle fluorescence fundus angiography (UWFFA). Using this method, it is possible to quickly determine the area to be described, avoid the radius of bleeding as much as possible, and provide the ophthalmologist with a range of damaged tissue and abnormal blood vessels. Nevertheless, there are cases in which ophthalmologists judge that fundus bleeding is so severe that ultra-wide-angle fluorescence fundus angiography is meaningless. In such cases, ophthalmic ultrasound and electroretinogram may be used in that order as alternative methods of examination. Therefore, some clinical situations require the use of ophthalmic ultrasound and electroretinogram and should be performed accurately.