• Journal of Korean Ophthalmic Optics Society
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• v.10 no.1
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• pp.41-46
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• 2005

The aim of the study was performed the wave analysis of P-VEP on the normal monocular vision and amblyopia in binocular. The P-VEP of three channels were recorded by the Nicolet system. Five adults (three males, two females, mean=22 years, range=19 to 24) subjects were recorded The subjects were researched the history including the systemic health, medication, genetics, allergy and ocular disease. Visual acuity and stereopsis were recorded for each subject monocularly and binocularly. Also subjects viewed the P-VEP stimulus both monocularly and binocularly through the corrected visual acuity during the VEP were recorded. The results of study suggest that the visual acuity of binocularly is better than with monocularly and the stereopsis was about over 140 sec. On the other hand, the analysis of P-VEP suggest that the amplitude of wave is larger when the monocular eye receives the P-VEP stimulus compared with the binocular eye. However the amplitude of wave in amblyopia had more smaller than the normal monocular The latency period of P-VEP was similar to results between the normal eye and binocular vision. But the amblyopia was a long period compared with the normal monocular and binocular vision. In conclusion, this study indicated that the visual acuity of binocularly have a better than the normal monocular vision, But in the P-VEP test, the amplitude of wave on normal monocularly vision appears to be better through the binocularly. But the amblyopia appeared the low amplitude wave of P-VEP and decreased the visual acuity.

• 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.

• Quality Improvement in Health Care
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• v.5 no.1
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• pp.128-138
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• 1998

Background : There is increased recognition that rigorous approach to functional assessment will complement the assessment of clinical status. This study is to develop the appropriate visual function index in Korean patients with cataracts by the assessment of the reliability, validity of visual function indexes including VF-14. Methods : An prospective study was performed with 92 patients who had undergone either one eye or both eye cataract surgery by 3 ophthalmologists practicing at a university hospital. Patients were interviewed. and clinical data were obtained. Doctors were questioned with self-entered questionnaire forms. Medical record was examined to understand surgery process. The survey was conducted at 1-2 days before cataract surgery. Results : We used following measures : 7 visual function indexes, global measures of patients' trouble and satisfaction with vision, and best-corrected visual acuity(VA) in each eye. 7 visual function indexes showed a high internal consistency reliability (Cronbach's alpha coefficients ${\geq}$ 0.86). The better visual acuity(operated eye, better eye), the higher patient satisfaction with vision, the lower symptom score, the lower patient trouble with vision was correlated with preoperative visual function index scores. Among 7 indexes, VF-12 with the exclusion of 2 items drivings from VF-14 is a high Cronbach's alpha coefficient and correlation coefficient and the highest $R^2$. Conclusion : We conclude that VF-12 is reliable and valid in Korea. So we suggest that in Korea, all items of VF-14, the visual function index, which is in use internationally, ought to be surveyed and VF-12 which has been excluded by 2 items of drivings from VF-14 ought to be used for analysis.

• Journal of Korean Neurosurgical Society
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• v.57 no.1
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• pp.23-31
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• 2015

Objective : The aims of this study were to investigate the quantitative relationship between pituitary macroadenoma size and degree of visual impairment, and assess visual improvement after surgical resection of the tumor. Methods : The medical records of patients with pituitary adenoma, who had undergone trans-sphenoidal adenectomy between January 2009 and January 2011, were reviewed. Patients underwent an ocular examination and brain MRI before and after surgery. The visual impairment score (VIS) was derived by combining the scores of best-corrected visual acuity and visual field. The relationship between VIS and tumor size/tumor type/position of the optic chiasm was assessed. Results : Seventy-eight patients were included (41 male, 37 female). Thirty-two (41%) patients experienced blurred vision or visual field defect as an initial symptom. Receiver operating characteristic curve analysis showed that tumors <2.2 cm tended to cause minimal or no visual impairment. Statistical analysis showed that 1) poor preoperative vision is related to tumor size, displacement of the optic chiasm in the sagittal view on MRI and optic atrophy, and 2) poorer visual prognosis is associated with greater preoperative VIS. In multivariate analysis the only factor significantly related to VIS improvement was increasing pituitary adenoma size, which predicted decreased improvement. Conclusion : Results from this study show that pituitary adenomas larger than 2 cm cause defects in vision while adenomas 2 cm or smaller do not cause significant visual impairment. Patients with a large macroadenoma or giant adenoma should undergo surgical resection as soon as possible to prevent permanent visual loss.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.1
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• pp.9-13
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• 2002

It is well known that the maximum amplitude of accommodation decreases with increasing age.(Presbyopia). With single vision lenses presbyopia can be corrected only for one viewing distance. With progressive power lenses presbyopia can be corrected for all viewing distances. But there are some other changes in the visual system with age which can not be corrected by spectacle lenses. Pupillary diameter decreases and the light transmission of the ocular media decreases. Therefore old people need more light, they need better illumination. Cone density in the retina decreases, this is only one example for changes in the sensory system. These changes in the visual system cause changes in visual functions. At the age of 80 visual acuity has decreased to half. Contrast sensitivity for gratings decreases mainly for high spatial frequencies very important is the increase of stray light in the ocular media and therefore the increase of glare. Veiling luminance increases by a multiple of approximately 4, Dark adaptation gets slower and light sensitivity is approximately 2 log units (factor 100) less when the eye is completely dark adapted. Also colour vision gets worse, especially at low luminances. Elderly people have problems with visual tasks which require divided attention between foveal and peripheral vision. An example is the measurement of the useful field of view. This useful field of view be expanded (improved) by visual training.

• Parasites, Hosts and Diseases
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• v.50 no.1
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• pp.73-78
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• 2012

We report a case of intraocular gnathostomiasis diagnosed by western blot assay in a patient with subretinal tracks. A 15-year-old male patient complained of blurred vision in the right eye, lasting for 2 weeks. Eight months earlier, he had traveled to Vietnam for 1 week and ate raw wild boar meat and lobster. His best-corrected visual acuity was 20/20 in both eyes and anterior chamber examination revealed no abnormalities. Fundus examination showed subretinal tracks in the right eye. Fluorescein angiography and indocyanine green angiography showed linear hyperfluorescence of the subretinal lesion observed on fundus in the right eye. Ultrasound examination revealed no abnormalities. Blood tests indicated mild eosinophilia (7.5%), and there was no abnormality found by systemic examinations. Two years later, the patient visited our department again for ophthalmologic evaluation. Visual acuity remained 20/20 in both eyes and the subretinal tracks in the right eye had not changed since the previous examination. Serologic examination was performed to provide a more accurate diagnosis, and the patient's serum reacted strongly to the $Gnathostoma$ $nipponicum$ antigen by western blot assay, which led to a diagnosis of intraocular gnathostomiasis. This is the first reported case of intraocular gnathostomiasis with subretinal tracks confirmed serologically using western blot in Korea.

• Archives of Plastic Surgery
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• v.39 no.1
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• pp.31-35
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• 2012

Background : Orbital roof fractures are frequently associated with a high energy impact to the craniofacial region, and displaced orbital roof fractures can cause ophthalmic and neurologic complications and occasionally require open surgical intervention. The purpose of this article was to investigate the clinical features and treatment outcomes of orbital root fractures combined with neurologic injuries after early reconstruction. Methods : Between January 2006 and December 2008, 45 patients with orbital roof fractures were admitted; among them, 37 patients were treated conservatively and 8 patients underwent early surgical intervention for orbital roof fractures. The type of injuries that caused the fractures, patient characteristics, associated fractures, ocular and neurological injuries, patient management, and treatment outcomes were investigated. Results : The patients underwent frontal craniotomy and free bone fragment removal, their orbital roofs were reconstructed with titanium micromesh, and associated fractures were repaired. The mean follow up period was 11 months. There were no postoperative neurologic sequelae. Postoperative computed tomography scans showed anatomically reconstructed orbital roofs. Two of the five patients with traumatic optic neuropathy achieved full visual acuity recovery, one patient showed decreased visual acuity, and the other two patients completely lost their vision due to traumatic optic neuropathy. Preoperative ophthalmic symptoms, such as proptosis, diplopia, upper eyelid ptosis, and enophthalmos were corrected. Conclusions : Early recognition and treatment of orbital roof fractures can reduce intracranial and ocular complications. A coronal flap with frontal craniotomy and orbital roof reconstruction using titanium mesh provides a versatile method and provides good functional and cosmetic results.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.145-150
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• 1998

To 160 persons(90 men, 70 women) who went to the national hospital of Solok-island with Hansens's disease, I tested the objective refracts test with the product of Cannon Ltd. Co. which RK-3 Auto Ref-keratometer's auto ophthalmoscope. The results were like these. Visual acuity of above 0.7 that can live without glasses was contained 44 men's eyes(24.4%) and 19 women s eyes(13.6%). These result are indicated that men have had more good visual acuity than women. Visual acuity of below 0.6 that cannot do normal life was contained 80.3% of the total patients. And amblyopia of below 0.3 and eyes which cannot be corrected were shown 44.4%(80 men's eyes and 55.7% 78 woman's eyes). Myopia was contained 119 eyes(43), hyperopia was contained 139 eyes (50.4%) and emmetropia was 6.5%. Astigmatism was shown 136 men s eyes (86.6%) and 97 women's eyes(81.5%). These results are indicated what many people accompany with astigmatism. And these ratio had some high percentages men rather than women. Direct astigmatic was contained 37 eyes (11.6%), Indirect astigmatic 81 eyes(25.3%) and Oblique Astigmatic 115 eyes(35.9%). As a of distributed result oblique astigmatic occupied best high point as 49.4% in 233 astigmatism and distributed the opposite direction as compared with normal irregular emmetropia not patient.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.4
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• pp.71-75
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• 2009

Purpose: This study was designed to investigate the condition of refractive correction and heterophoria and monocular pupillary distance on myopic elementary school children wearing glasses in Gwangju city. Methods: Subjective refraction and objective refraction were examined after investigating heterophoria and monocular pupillary distance on 145 (290eye) elementary school children wearing myopia-corrected glasses. Results: 1. Anisometropia > 2.00 D was present in 4 children (3%). 2. 9 anisometropia (47%) were present in 19 undercorrected visual acuity boy wearers. and 16 anisometropia (64%) were present in 25 undercorrected visual acuity girl wearers. 3. Among the 67 myopic glasses boy wearers, the distance between optical centers was coincided with the pupillary distance in 30% (Oculus Uterque), and discrepant in 70% (Oculus Uterque). Among the 78 myopic glasses girl wearers, the distance between optical centers was coincided with the pupillary distance in 23% (Oculus Uterque), and discrepant in 77% (Oculus Uterque). The mean optical center distance was longer than the pupillary distance on both boy and girl wearers 4. The result of measured heterophoria revealed 14% for orthophoria, 63% for exophoria, 23% for esophoria at far distance and 10% for orthophoria, 76% for exophoria, 14% for esophoria at near distance. Conclusions: Correct refractive test and monocular pupillary distance must be examined because incorrect refractive test and pupillary distance induce asthenopia and heterophoria.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.2
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• pp.165-171
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• 2013

Purpose: This study are to analyze and to compare between pupillary size, reaction time, refractive error, corrected vision, dominant eye, static visual angle (SVA) and kinetic visual acuity (KVA) of male and female college students, to measure KVA of them in full correction and to identify changes of KVA by +0.50 D and -0.50 D spherical power addition respectively in full correction condition. Methods: KVA, SVA, pupillary size, reaction time, refractive error, corrected vision and dominant eye of 40 male and 40 female optical science students were measured by utilizing KOWA AS-4A, reaction time measurement program, subjective refractometer, and objective refractometer, and KVAs were measured when +0.50 D/-0.50 D were added in both eyes respectively. Results: Binocular KVA of whole subjects was $0.45{\pm}0.22$, and in monocular KVAs were $0.36{\pm}0.19$ for right eye and $0.34{\pm}0.19$ for left eye, and binocular KVA was significantly higher than monocular KVA. It appeared that the better SVA was, the better KVA was in significant way, and in terms of refractive error the less myopia amount was, the better KVA was, but it was not significant statistically. The lower astigmatism was, the slightly and significantly higher KVA was when dividing between equal or less than -1.00 D astigmatism group and over -1.00 D astigmatism group. In resulting from correction condition of refractive error KVAs were $0.45{\pm}0.22$ for full correction, $0.26{\pm}0.15$ for +0.50 D addition, $0.48{\pm}0.22$ for -0.50 D addition which indicates that KVA in over myopia correction was significantly the highest and followed by full correction and under correction. Similar findings were revealed in both male and female, and KVA of male was better than female in comparing between male and female. There was no significantly different KVA between dominant eye and non-dominant eye. Conclusions: Accordingly, it is concluded that KVA is related with far distance SVA, astigmatism amount, and refractive error amount except a dominant eye. Through this research, it was found that prescription for enhancing KVA is to make full correction or to overcorrect slightly myopia.