• Title/Summary/Keyword: 근시

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건강백과

  • KOREA ASSOCIATION OF HEALTH PROMOTION
    • 건강소식
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    • v.1 no.3
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    • pp.47-49
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    • 1973
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The Efficacy and Effect of Reverse Geometry Contact Lens on Cornea (역기하학 렌즈의 유효성과 각막에 미치는영향)

  • Kim, Kwang-Bae;Kim, Young-Hoon;Bark, Sang-Bai;Sun, Kyung-Ho;Jeong, Youn-Hong
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.2
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    • pp.1-12
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    • 2007
  • Object of this research is to estimate the effect of myopia correction and safety on reverse geometry contact lens fitting in school children. This research include 53(106eyes) schoolchildren among 7 to 18 years who has low to moderate myopia(-1.00D~-5.00D) and prescribed reverse geometry contact lens for purpose on orthokeratology between January to July 2004 and had 3months full follow up examination. They were tested for slit lamp examinations, BUT(Break up time), direct ophthalmoscopy, retinoscopy, uncorrected visual acuity, best corrected visual acuity, autorefraction, autokeratometry and corneal topography in each examination(1day, 1week, 2weeks, 1, 2, and 3months) of before-and-after lens wearing to find out the effect of myopic correction and side effect. The results came out as follow. The average of uncorrected visual acuity was $0.0938{\pm}0.378$ before lens wear and $0.3136{\pm}0.283$ after 1day lens wear, and there was fast improvement after 1week($0.7925{\pm}0.301$) and little improvement after 2weeks period but still they shows better uncorrected visual acuity(p<0.01). The result of this study, the reverse geometry lens is very useful to correct refractive error and control the progression of myopia temporally among low to moderate myopic patient. The side effects were relatively rare but further study should be necessary with long term lens wear effect on eye health. For the lens prescription, the clinical fitting process had higher rate of success with consideration of eccentricity and corneal topography.

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Comparison of Clinical Results of Excimer Laser Correction of Myopia and Compound Myopic Astigmatism Using VISX 20/20B $VisionKey^{TM}$ (VISX 20/20B $VisionKey^{TM}$ 엑시머레이저의 version 4.01 software를 이용한 근시교정술 및 근시성난시교정술의 임상성적 비교)

  • Lee, Sang-Bumm;Bae, Sang-Bok
    • Journal of Yeungnam Medical Science
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    • v.17 no.1
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    • pp.55-65
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    • 2000
  • Purpose: To compare the efficacy, predictability, stability and safety of excimer laser photorefracive keratectomy(PRK) for myopia and photoastigmatic refractive keratectomy(PARK) for compound myopic astigmatism. Methods: Two-hundred and three eyes(l18 eyes < -7D spherical equivalent, 85 eyes ${\geq}$ -7D spherical equivalent) received excimer laser correction for compound myopic astigmatism and 152 eyes(116 eyes < -7D, 36 eyes ${\geq}$ -7D) for simple myopia. A VISX 20/20B $VisionKey^{TM}$ excimer laser was used to perform either PARK or PRK. Visual acuity with and without correction, refraction, IOP, corneal haze, and topography were evaluated at 1, 3, 6, and 12 months postoperatively. All patients were followed up for more than 12 months. Results: Postoperative refraction were generally stable after 3 months without significant early overcorrection. At 12 months, 110(94.8%) eyes that underwent PRK and 104(88.1%) eyes that underwent PARK achieved UCVA of 20/30 or better in the group who had lower than -7D correction. For eyes treated with -7D or more, these figures were 31(86.1%) eyes after PRK and 57(67.1%) eyes after PARK. The incidences of within 1D of plano refraction at 1 year follow-up were 97.4% after PRK and 93.2% after PARK in the group who had lower than -7D correction. For eyes treated with -7D or more, these figures were 80.6% after PRK and 70.6% after PARK. Conclusions Myopia with or without astigmatism was successfully treated in most of the eyes using PRK or PARK with VISX 20/20B $VisionKey^{TM}$ excimer laser. The predictability and stability of the postoperative refraction during the first 12 months seem to be quite reliable. Further improvement of excimer laser system and software should increase the clinical outcomes and safety of refractive procedures.

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A Comparative Study on the Ametropias of Philippines and Koreans (한국인과 필리핀인의 굴절이상에 대한 연구)

  • Lee, Hark-Jun;Kwen, Man-Sung
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.4
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    • pp.477-482
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    • 2012
  • Purpose: This study is aimed at finding the conditions of ametropia of adults in the Philippines and the South Korean. Methods: The study objects were 7,695(15,390 eyes) Koreans and 2,256(4,512 eyes) Philippines who visited optic clinics and took refraction test. The distributions of their hypermetropias and myopias about astigmatisms were examined, using the method of equivalent spherical power. When astigmatisms were marked in S-C, cylinder lens diopter and astigmatism axis, presbyopic additions and pupillary distances were analyzed by comparison respectively. Results: Among ametropias of Koreans myopias and hypermetropias were 93.69% and 6.31% respectively and about ametropias of Philippines myopia and hypermetropias were 73.43% and 26.57% respectively. As for spherical equivalent power about Koreans, the results showed that Koreans marked -3.352 D about myopia and Philippines marked -2.213 D about it. There is a gap of -1.139 D between them. About hypermetropia Koreans marked 1.147 D and Philippines, 1.251 D and their gap is 0.104 D. As for ametropia of Koreans there is 49.86% in middle myopia, 32.28% about low myopia, 11.55% about high myopia, and 5.54% about low hypermetropia, 0.75% about middle hypermetropia. As for it about Philippines there is 44.53% in low myopia, 25.11% about middle myopia, 3.79% high myopia and 23.03% low hypermetropia, and 3.51% low hypermetropia respectively. As for cylinder lens there is differences of 0.194 D and 0.22 D between Korean and Philippine for both sexes. Totally Koreans have higher cylinders of 0.175 D than Philippines. As for astigmatism, Koreans have direct astigmatism, inverse astigmatism, and oblique astigmatism in their suffering sequence. As for Philippines, they have direct astigmatism, inverse stigmatism, and oblique astigmatism in their abnormal sequence, and they have higher oblique stigmatism than Koreans. As for presbyopic addition, Philippines have higher distributions than Koreans, and 0.296 D is higher in average. As for pupillary distance, Koreans have longer distance of 0.97 mm in man and 0.63 mm in women than Philippines. Conclusions: As for ametropia, Koreans and Philippines have more myopias than hypermetropias, but Philippines have more rates of hypermetropias than Koreans. And Philippines have more presbyopic additions. Koreans have higher morbidity of inverse astigmatism, and Philippines have higher morbidity of oblique astigmatism comparatively. As for pupillary distance, Koreans have longer length in the body characteristics. This shows that geographical circumstances have much to do with refraction conditions of eyes.

Reliability of Autorefractometry after Corneal Refractive Surgery (레이저 굴절교정수술 후 자동굴절검사법의 신뢰성)

  • Lee, Ki-Seok
    • The Korean Journal of Vision Science
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    • v.20 no.4
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    • pp.443-451
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    • 2018
  • Purpose : To find out the reliability of autorefractometer after laser refractive surgery Methods : We measured and compared spherical and cylinder powers of those undergone LASEK surgery with 1.0 of naked vision after at least 3 months of the surgery with an autorefractometer(CANON Full Auto Ref-Keratometer RK-F1, Japan) and a retinoscope(Streak Retinoscope 18200, WelchAllyn, USA), and also applied spherical equivalent powers. The refractive status before surgery was divided into high, medium, and low myopia according to the results measured using an autorefractometer, and then analyzed again the reliability of the autorefractometer after surgery according to the preoperative refractive status. The agreement of two methods was identified using Bland-Altman(Bland-Altman limits of agreement(LoA)). Results : After the surgery, when comparing spherical, cylinder and equivalent powers in the whole data measured by autorefractometry and retinoscopy significant differences were found(p<0.01). According to the degree of refractive errors, all sort of refractive errors was shown significantly different(p<0.01) except for cylinder power of the medium myopia. In general, the refractive errors especially spherical and spherical equivalent powers by autorefractometry were shown a myopic trend from -0.38 D to -0.53 D. On the other hand, it was shown a hyperopic trend of approximately +0.30 D using retinoscopy. In comparison of two objective refractions, it was shown a myopic trend as $-0.51{\pm}0.45D$(LoA +0.36 D ~ -1.39 D) and compatible. Conclusion : Even though it would be positive in terms of compatibility of the methods, it is necessary that the glasses should be prescribed by subjective refraction since autorefractometry is shown myopic in those undergone the surgery and suffering from myopic regression.

A test of Visual Acuity and Refractive error to Kindergarten's Children (유치원 어린이 나안시력과 굴절이상 측정)

  • Kang, I.S.
    • Journal of Korean Ophthalmic Optics Society
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    • v.3 no.1
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    • pp.87-92
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    • 1998
  • Unaided visual acuity was tested by ACP-7 TOPCON chart projector on 376 kindergarteners and objective refraction error was measured by NIDEK ARK-700A auto-refractokeratometer on 554 eyes aged 3 to 5. The results were as follows ; The average unaided visual acuity of children aged 3 was 0.82, aged 4 was 0.90 and aged 5 was 0.92 respectively theerfore children s visual acuity has been gradually developed with their age. The kind of refractive error was 1% for hyperopia, 14% for hyperopic astigmatism, 3% for myopia, 50% for myopic astigmatism, 18% for mixed astigmatism and 14% for emmetropia respectively.

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