• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.391-396
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• 2004

For the prevention of amblyopia, early discover and treatment is very important. Therefore we evaluated the type and the degree of refractive errors of 39 children with anisometropic and refractive amblyopia aged 3 to 12 years, and studied the relationship of astigmatism and amblyopia. Astigmatism was found in 35 of 39 eyes. Of these 35 eyes, with the rule astigmatism was found in 30 eyes. The cylinderical power was distributed mostly from 0.50D to 6.50D and astigmatism did not appear to influence on the initial and final corrected visual acuity.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.137-142
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• 2007

The purpose of this study was to investigate sole effect of therapy of spectacles correction on the refractive amblyopia. Spectacles were prescribed to give the same effect as the occlusion therapy undercorrecting in the case of hyperopia, and effectiveness of the therapy was compared with occlusion therapy without additional prescription. The results can be summarized as follows: 1. The higher anisometropic power was the lower initial visual acuity was. 2. Anisometropic power did not influence final visual acuity. 3. The latter beginning time of therapy was the higher astigmatism was. 4. Therapy of spectacles correction on the hyperopic amblyopia was quite effective.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.551-555
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• 2014

Purpose: This study is to investigate if the improvement of visual sensory (VS) by amblyopia treatment affects the ocular functions in refractive errors, accommodative errors and phoria at distance and near. Methods: 10 subjects (17 eyes, mean age of $10.7{\pm}2.9$ years) who treated amblyopia completely, were participated for this study. Refractive errors, accommodative errors, and distance and near phoria were compared between before and after treatments of amblyopia. Refractive errors and accommodative errors at 40 cm were measured using openfield auto-refractor (NVision-5001, Shin Nippon, Japan) and using monocular estimated method (MEM) respectively. Phoria was determined at 3 m for distance and at 40 cm for near using Howell phoria card, cover test or Maddox rod. Results: Mean corrected visual acuity (CVA) significantly increased from $0.46{\pm}0.11$ (decimal notation) for before amblyopia treatment to a level of $1.03{\pm}0.13$ for after amblyopia treatment (p < 0.001). For spherical refractive error, hyperopia significantly decreased from $+2.29{\pm}0.86D$ to a level of $+1.1{\pm}2.38D$ (p < 0.05) but astigmatism did not significantly change; $-1.80{\pm}1.41D$ for before treatment and $-1.65{\pm}1.30D$D for after treatment (p > 0.05). Accommodative error significantly decreased from accommodative lag of $+1.1{\pm}0.75D$ to a level of $+0.5{\pm}0.59D$ (accommodative lag) (p < 0.05). Distance phoria significantly changed from eso $2.9{\pm}6.17PD$ (prism diopters) to a level of eso $0.2{\pm}3.49PD$ (p < 0.05), and near phoria also significantly changed from eso $0.4{\pm}2.32PD$ to level of exo $2{\pm}4.9PD$ (p < 0.05). There was a high correlation (r = 0.88, p < 0.001) between improvement of visual acuity and decrease of accommodative lag. Conclusions: Hyperopic refractive error decreased with improvement of CVA or VS by amblyopia treatment. And the improvement of VS by amblyopia treatment also improved accommodative error, and changed phoria coupled with accommodation.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.2
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• pp.95-106
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• 2007

The purpose of this study was to investigate effect of spectacle correction therapy instead of occlusion therapy for refractive amblyopia treatment. Spectacle correction were prescribed to give the same effect as a occlusion therapy by under correction for normal eye and there was no additional treatment but only spectacle correction for hyperopic amblyopia. The results can be summarized as follows: 1. In hyperopic amblyopia after correction, initial visual acuity($Mean{\pm}SD$) was $0.36{\pm}0.13$ and final visual acuity($Mean{\pm}SD$) was $0.82{\pm}0.23$. 2. Regardless with age, there was significant differences between initial acuity and final acuity, it shows improvement in visual acuity after spectacle correction treatment. 3. Initial correction age did not influence the length of treatment and success rate of treatment, so that ambyopia correction effect not related with age. 4. Compared with initial visual acuity with final visual acuity, initial visual acuity was in proportion to final visual acuity. 5. Incidence was higher in hyperopia and hyperopic astigmatism than myopia and myopic astigmatism in refractive amblyopia group and the therapy was more effective for hyperopia and hyperopic astigmatism than myopia and myopic astigmatism. 6. Treatment was effective even for children who is older than 8 years.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.345-352
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• 2004

We investigated the effect of age at initial correction, of 44 refractive amblyopic patients duration of correction on corrected visual acuity with the lapse of time for mean 33months(3months-59months). Full cycloplegic corrections were prescribed at the initial visit to all subjects. The distribution of initial corrected visual acuity was 0.02 to 0.5. Age at initial correction varied from 3 years to 12 years. The refractive error appeared to have the greatest influence on the visual outcome, showing continuous visual improvement after initial correction. But the age at initial correction did not appear to influence on the initial and final corrected visual acuity showed a significant difference, irrespective of age at the initial correction Or degree of anisometropia.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.111-117
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• 2007

The visual evoke potential(VEP) is the effective method to diagnose and treat the amblyopia or to check the infants visual ability. In order to evaluate the changes of P100 latencies and amplitudes of VEP by intensity of illumination and refractive errors, we measured latencies and amplitudes of 41 normal adults (20/20 VA) who have no ocular diseases and neurologic diseases. The results were as follows: In the scotopic condition, the latencies were N75$75.83{\pm}3.69$ msec, P100$103.48{\pm}5.34$ msec, the P100 amplitude was $14.86{\pm}2.43$ msec, and in the photopic condition, the latencies were N75$76.71{\pm}3.11$ msec, P100$107.26{\pm}5.54$ msec and the P100 amplitude was $10.35{\pm}1.75$ msec. The latencies and amplitudes of P100 in the photopic condition had higher values than those in the scotopic condition and the measures were significantly different between the scotopic and photopic condition (p<0.01). The P100 latencies were delayed both in the scotopic and photopic condition with the refractive errors and those measures were delayed more than in the photopic condition. The P100 amplitudes in the induced myopic and hyperopic conditionsreduced than in the emmetopes in both illumination conditions. The P100 latencies and amplitudes in emmetropes showed a correlation with the induced myopic conditions in the scotopic condition. Those results showed that P100 latencies and amplitudes are dependent on the illumination conditions and refractive errors. And we suggest that those results would be useful to determine and evaluate the normal range for the person considering patients' refractive errors and illumination of the test room.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.275-280
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• 2006

For this study, we analysed the difference of values between noncycloplegic and cycloplegic autorefraction in primary school children. We classified the elementary school one, two, three grade (8~10age) 79children(158eyes) who did not have strabismus or amblyopia. They were examined by using the Autorefractor in domestic market before and after cycloplegic. Discrepancies beyond 0.50D in spherical and cylindrical power and 20 degree in cylindrical axis were regarded as significant. The percentages of discrepancy were greater in spherical power between noncydoplegic and cycloplegic autorefraction(p<0.05). The percentages of discrepancy were not greater in cylindrical power between noncycloplegic and cycloplegic autorefraction. The percentages of discrepancy were greater in cylindrical axis between noncydoplegic and cycloplegic autorefraction(p<0.05). In conclusion, for the primary school children who did not wear glasses, the prediction table of this study will be helpful to reduce the test error in visual acuity and refractive error tests.

• Korean Journal of Health Education and Promotion
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• v.10 no.1
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• pp.87-97
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• 1993

The purpose of this study is to give practical information about eyesight care-preventing refractive error and actual conditions of wearing glasses(or contact lenses) to help school health education, For this study, 1,216 freshmen were sampled from liberal and vocational high schools in Seoul and the survey was successfully accomplished. Following are the major findings results of this study: 1. The percentage of the freshmen wearing glasses in girls high school were 57.5 percent in liberal high school and 41.7 percent in vocational high school. 2. The percentage of both the students and parents wearing glasses were 49.9 percent in liberal high school and 33.8 percent in vocational high school. 3. From the survey, the majority of the students began to wear glasses during their middle school years. The percentages were 46.6 percent in liberal high school and 62.1 percent in vocational high school. 4. The percentage of the students who got their glasses prescribed from an ophthalmic clinic were 60.6 percent in liberal high school, 31.5 percent in vocational high school and the rest got their glasses from the optician.. 5. The percentage of the students wearing glasses who didn't have optometry check-up for 6 months were 57.2 percent in liberal high school and 38.4 percent in vocational high school. The percentage of the students not wearing glasses in the same situation were 61.9 percent in liberal high school and 41.5 percent in vocational high school. 6. The percentage of the students who believe that the health education in school is necessary for the prevention of amblyopia were 79.2 percent of strdents attending in liberal high school, 82.9 percent in vocational high school, 81.5 percent of students wearing glasses and 80.8 percent of students not wearing glasses.

• 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.19 no.3
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• pp.371-376
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• 2014

Purpose: The aim of this study was to explore the effect of artificially decreased eye in normal vision on eye-hand coordination (EHC) when using the Lee-Ryan Eye-Hand Coordination Test recently reported. Methods: Eleven adults with normal vision aged $29.46{\pm}5.94$ years participated for this study where a non-dominant eye artificially induced moderate refractive amblyopic vision at near by adding a plus lens conducted EHC tasks and then did the test again under normal vision following 2 weeks. To investigate the ability of EHC, 7 tasks including individually different level of difficulty in the Lee-Ryan EHC Test were selected to compare and analyze EHC in terms of two independent variables such as time taken and the number of errors. Results: In time taken, subjects with artificially decreased vision took more time than normal vision under monocular conditions (p=0.013), while those with the decreased vision completed their tasks faster than normal vision under binocular conditions (p=0.001). In the number of errors, subjects with the decreased vision made more mistakes (p<0.001) as shown in time taken, whereas there was no difference between monocular and binocular viewing conditions in the decreased vision. Conclusions: Unlike previous EHC tests including limitations for application, deficit in EHC can be screened by the Lee-Ryan EHC Test developed based on simple computer-based system. Therefore, it is considered that further studies relevant to deficits in visual function such as amblyopia will be carried out in clinics as well as research.