• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.523-530
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• 2018

Purpose : The purpose of this study was to investigate the difference in the dynamic visual acuity between (DVA) the distance and near and the effect of change of accommodative stimulus on the dynamic visual acuity by the addition of the plus lens. Methods : The study involved 40 male and female adults ($22.84{\pm}2.43$ years old) with over 1.0 of visual acuity and without systemic disease or ocular disease. We compared the distance and near DVA and the change of DVA induced by the addition of the plus lens(+0.50D, +1.00D, +1.50D). Results : The distance DVA and near DVA are $78.86{\pm}19.46deg/sec$ and $76.90{\pm}18.05deg/sec$ respectively. The distance DVA was slightly higher(p=0.04). The higher the distance DVA, the higher the positive correlation with the near DVA and distance DVA, and distance DVA was higher in those who had higher the near DVA(r=0.95, p=0.00, Fig. 4). The near DVA according to the change of accommodative stimulus was $75.95{\pm}18.85deg/sec$ in full correction and the near DVA with +0.50D spherical power was $76.95{\pm}16.45$ but there was no statistically significant differences(p>0.05). However, the near DVA with +1.00D spherical power was $79.02{\pm}13.51deg/sec$ and it was slightly higher. Also, the near DVA with +1.50D spherical power was $84.28{\pm}18.96deg/sec$, there and it was statistically significant difference(p<0.05). Conclusion : There is no difference between distance and near DVA, but near DVA is also excellent if distance DVA is good. The DVA increases as added a plus lens for controlled accommodative stimulation changes.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.201-206
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• 2006

The purpose of this study is observed effect of cycloplegia in emmetropia with use of cycloplegia. We examined the naked visual acuity, mainfest refraction, 105eyes with emmetropia(under SE ${\pm}0.50D$, Cyl ${\pm}1.00D$) after the use of cycloplegia. We used Nidek ARK-700 autorefractometer. Sexual difference of mainfest refraction error showed in male -0.67D, female -0.92D and difference of the CR and the MR male 0.5D, female 0.81D the total mean 0.69D. The naked visual acuity were in male 0.82, female 0.74, total mean 0.77. Age comparison, difference CR and MR were total mean 0.69D and 13 years group 1.1D were the highest. The naked visual acuity were in the highest 10 years group 0.86. Effect of cycloplegia was $0.69D{\pm}0.79$ in emmetropia and visual acuity was $0.77{\pm}0.21$. The optician, it will not be able to use cycloplegia, must pay attention spectacle prescription unnecessary and over correction in condition below -0.75D MR, above 0.77 visual acuity.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.1
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• pp.77-81
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• 2016

Purpose: This study was performed to investigate the difference of meridional visual acuity and the loss of corrected visual acuity (VA) in order to emphasis the importance of astigmatic correction. Methods: 64 subjects (122 eyes) aged $22.75{\pm}2.36years$ participated in this study. After full correction of astigmatic refractive error, VA was measured in which the direction of the slit filter was matched with astigmatic axis and $90^{\circ}$ to the astigmatic axis. Results: 52 eyes showed no difference in VA between the two direction. However 70 eyes had difference VA between them. 14 out of 52 eyes and 24 out of 70 eyes had under 1.0 in monocular VA. The astigmatic degree was higher in the existence of VA difference between the two direction than non-existence. The difference is higher with under 1.0 monocular VA. Monocular VA is closely related to the focal line having better VA in the principal focal line. Glasses replacement period was analyzed as 6~12 months for the preservation of better VA. Conclusions: The final glasses prescription has to be given with full correction because continued under-correction for astigmatism causes meridional VA difference.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.113-117
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• 2008

Purpose: This study is to survey that uncomfortable feeling of visual acuity in the first wearing glasses, the number of visiting in age, above vision ranging and refractive errors, astigmatism, and anisometropia. Methods: Automatic refraction and naked visual acuity test executed to receive prescription glasses that the man 509 and women's 499 people visited for the first time, among 3~15 years old who visited an ophthalmoiogical hospital, from January to December, 2003. Results: The first wearing glasses started 3 years old and the most cases was 8~9 years old when they were visited visual acuity 0.5 to 0.7 in most cases. Refractive errors appeared 8 years old and its most plentifully with 20.4%, 92.2% was myopia and 5.2% was hyperopia for the man. Also cases of women was 91.9% for myopia and 5.1% for the hyperopia. Spherical equivalent power was S-1.50${\pm}$1.10D and appeared 62.3% for the low myopia. Astigmatism was appeared 44.6% for the with the rule astigmatism and 75% was cylinder power lower than 1.00D. Cases of simple astigmatism need to glass when was cylinder power C-1.37${\pm}$1.01D, and C-0.50D appeared most distribution. More than 2.00D anisometropia appeared 2.3% for the whole subjective. Conclusions: Of the first wearing glasses visual acuity is 0.5~0.7, spherical equivalent power is S-1.50${\pm}$1.10D, cylinder power of simple astigmatism is C-1.37${\pm}$1.01D.

• 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.54 no.9
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• pp.1445-1451
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• 2013

Purpose: To report long-term changes in the average retinal nerve fiber layer (RNFL) thickness in 2 patients who had intravitreal bevacizumab (IVB) injection for diabetic papillopathy. Case summary: A 36-year-old patient with diabetes complained of decreased visual acuity (20/200) in the right eye. The fundus examination showed optic disc swelling in both eyes. The average RNFL thickness based on optical coherence tomography (OCT) increased to $278{\mu}m$ and Goldmann perimetry showed nasal visual field defect in the right eye. The IVB was injected into the right eye. Three weeks after the IVB injection, RNFL thickness decreased to $135{\mu}m$ and visual acuity improved to 20/25 in the right eye. However, RNFL thickness increased from 126 to $207{\mu}m$ and visual acuity decreased to 20/32 in the left eye. Thus, IVB was injected into the left eye. In week 3, RNFL thickness decreased to $147{\mu}m$ and visual acuity improved to 20/20 in the left eye. At 12 months after IVB injection, RNFL thickness was $87{\mu}m$ in the right eye and $109{\mu}m$ in the left eye. A 57-year-old patient with diabetes complained of decreased visual acuity (20/200) and showed optic disc swelling in the right eye. The average RNFL thickness increased to $252{\mu}m$ and Goldmann perimetry showed an enlarged blind spot in the right eye. IVB was injected into the right eye. After 3 weeks, RNFL thickness decreased to $136{\mu}m$ and visual acuity improved to 20/70 in the right eye. Six months after IVB injection, RNFL thickness was $83{\mu}m$ in the right eye. Conclusions: Visual acuity progressively improved within 3 weeks and RNFL thickness measured by spectral domain OCT showed progressive thickness reduction in 2 cases of diabetic papillopathy patients who had IVB injections.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.4
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• pp.13-19
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• 2003

Giving teachers and students the clean visual environment, the classroom lighting is an important part that prevents the decrease of the visual acuity and improves the studying environment. In order to improve the classroom lighting, a proper blackboard luminaire is to be developed. This paper explains how to design the optical form of the high efficient reflector which offers the uniform illuminance at the vertical surface of the blackboard and, after all, the problem of a large source in reflector design process is explained.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.2
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• pp.209-217
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• 2011

Purpose: In this study, eye-health inequity was investigated by analyzing the relationship between household incomes and eye-health of senior citizens. Further, this study suggested the preliminary data for establishment of public eye-health policy in order to improve low income senior citizens' life quality. Methods: The data from the 2009 Survey of Korea National Health and Nutrition Examination were analyzed in this study. The objectives of the KNHNE survey were over 65 year old group (1,668 people). Main factors of eye-health (visual acuity, cataract, pterygium, intraocular pressure, retinophathy, age-related macular degeneration, diabetic retinophathy, myopia, hyperopia, astigmatism, and anisometropia prevalence) were analyzed with t-test and chi square test. Results: Low income group revealed that refractive error rate and intraocular pressure were low, however, naked eye visual acuity and corrected visual acuity were high at 0.1 to less than 0.5. On the other hands, in the high income group, there was high prevalence of hyperopia. Cataract mainly occurred at low income group besides group which maximum corrected visual acuity was below 0.8 also highly showed cataract. Moreover, the prevalence of cataract showed that it related with smoking, drinking, occupation, and education level. Conclusions: Results revealed that there was inequity of eye-health which related with socioeconomic status of the elderly. Especially, the prevalence of cataract was correlated with life quality. Consequently, establishment of public eye-health policy seems to be required for eye-health inequity of low income senior citizens.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.6
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• pp.563-566
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• 2010

Retrobulbar abscess is a rare, but severe complication of paranasal sinusitis. The clinical presentations are eyelid swelling, erythema, proptosis, conjunctival chemosis, restricted ocular movement, and decreased visual acuity. Diagnostic methods available for evaluating retrobulbar abscess include sinus X-ray, ultrasonography, computed tomography (CT), and bacterial culture. For the treatment of retrobulbar abscess, immediate surgical drainage and systemic antibiotic therapy are needed. Proper diagnosis and treatments are necessary for preventing visual loss, cavernous sinus thrombosis, subdural abscess, and other lifethreatening complications. A patient, a 30-year-old man, was admitted to our hospital because of progressive eyelid swelling, erythema, ptosis and decreased visual acuity on the right eye after endodontic treatment. The sinusitis occurred secondary to the infection from an upper molar tooth. The spread of the infection led to the orbit via ethmoidal sinus and posterior orbital wall. Immediate surgical intervention was performed and systemic antibiotics was administrated. The symptoms and signs are improved after treatments, so we present our case with a brief review of the literature.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.549-554
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• 2013

Purpose: To determine the minimal illumination for visual acuity with the decimal vision chart and individual difference with varying contrast and illumination. Methods: Landolt's vision chart with 10 different grade of contrast was made. Minimal illumination was measured for 69 eyes using 100% contrast vision chart. Minimal contrast for identifying the chart was measured in conditions of the minimal illumination and 230 lx, respectively. Results: Minimal illumination was gradually increased with decrease of the chart size. Mean of minimal illumination to identify the 1.0 visual acuity was $74.39{\pm}25.90$ lx with range of 17~107 lx. In conditions of the minimal illumination and 230 lx, the minimal contrast for identifying the chart were gradually increased with decrease of the chart size in both conditions, the those deviation for 69 eyes was also increased. Conclusions: For refractive correction, examiners need to consider the individual difference for identifying the visual chart according to illumination and contrast.