• Title/Summary/Keyword: Astigmatism

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A Study for the Change of Astigmatism Axis When the Fixation Point Moved Far Distance to Near Distance (원거리에서 근거리 주시 시 난시축 변화에 대한 연구)

  • Joo, Seok-Hee;Sim, Hyun-Seog
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.2
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    • pp.47-59
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    • 2007
  • When the fixation point moved far distance to near distance, the change of astigmatism type in total astigmatism showed no-changed eyes: 1,020 eyes (63.8%), changed eyes: 578 eyes(36.1 %). The change of with-the-rule into oblique-astigmatism, oblique-astigmatism into with-the-rule, against-the-rule into oblique-astigmatism of change was plenty the most respectively. In corneal astigmatism was no-changed eyes: 1,164 eyes (72.8%), changed eyes: 434 eyes(27.1%). The change of with-the-rule into oblique-astigmatism, oblique-astigmatism into with-the-rule, against-the-rule into with-the-rule astigmatism was plenty the most respectively. In residual astigmatism is no-changed eyes: 935 eyes(58.5%), changed eyes: 663 eyes(41.4%). The change of with-the-rule into oblique-astigmatism, oblique-astigmatism into against-the-rule, against-the-rule into oblique-astigmatism was plenty the most respectively. When the fixation point moved far distance to near distance, the change of astigmatism axis in total astigmatism was no-changed eyes: 761 eyes(48.5%), cyclotorsioned eyes the above 10 degrees: 837 eyes(52.3%). In corneal astigmatism was no-changed eyes: 846 eyes(52.9%), cyclotorsioned eyes the above 10 degrees : 752 eyes(47%). In residual astigmatism was no-changed eyes: 614 eyes(38.4%), cyclotorsioned eyes the above 10 degrees : 984 eyes(62.5%). The magnitude of cyclotorsion of astigmatism axis in total astigmatism was Counter clockwise rotation: 31 degrees, clockwise rotation: 20 degrees. In coneal astigmatism was Counter clockwise rotation: 25 degrees, clockwise rotation: 27 degrees. In residual astigmatism was Counter clockwise rotation: 33 degrees, clockwise rotation: 35 degrees.

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A Study of Myopic Astigmatism Eyes on The Highschool Students (남녀고등학생의 근시성 난시안에 대한 연구)

  • Yoon, Kyoung-Han;Kang, Myung-Ki
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.1
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    • pp.159-163
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    • 2000
  • In this study, It obtained that how myopitic astigmatism eyes appear in highschool students. The results were as follows. 1. In test, myopitic astigmatism eyes of men students are measured 60% in ratio and women students are measured are 57% in ratio. 2. In $-1.00{\geq}$cyl>0.00 Dptr, myopitic astigmatism eyes are measured 82% in ratio and in $-1.50{\geq}$cyl>-1.00 that is measured 12% in ratio. 3. In -2.00>cyl, myopitic astigmatism eyes are measured 6% in ratio. 4. In the kind of astigmatism, The direct astigmatism axis is 81 % in ratio and each of the indirect astigmatism axis and the oblique astigmatism is 5%, 14% in ratio.

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A Study of Abnormal Refraction Eye on Female Old Age (노인 여성의 굴절이상 눈에 대한 연구)

  • Kim, Douk-Hoon
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.1
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    • pp.125-129
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    • 2000
  • To fine understand the visual acuity of female old age. This study was researched the visual acuity test by the object and subject methods. The major findings was as follows: 1. The eye types were 80.94% positive for hyperopia. 13.86% for myopia and 5.19% for emmetropia respectively. 2. The anbormal refraction eye was positive for mixed astigmatism for 78.27%, myoptic com pound astigmatism (10.99%), simple presbyopia(4.97%), myopic simple astigmatism(2.88%), presbyopia compound astigmatism (1.57%), simple myopia(0.78%) and presbyopia simple astigmatism(0.52%). 3. The axis of astigmatism was 60.23% for against regular astigmatism. 22.73% for oblique astigmatism and 17.05% for regular astigmatism respectively. 4. On the total myopic spheric power, the -0.50 spheric equivalent ${\leq}-2.00$ was 90.2%, the -2.00${\leq}-6.00$ was 9.8%. 5. On the total presbyopic spheric power, the -0.50${\leq}-2.00$ was 80.252%, the -2.00${\leq}-6.00$ was 16.99% and 2.56% for anything over the 6.00 diopter. 6. On the astigmatic power, the $0.50{\geq}$ cylinder power${\geq}1.00$ was 69.35%,the 1.00> cylinder power ${\geq}2.00$ was 27.38%, and anything over the 2.00 cylinder diopter was 3.27%.

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A Study of Eye Refraction state on old Age (노안의 굴절이상과 안경착용에 대한 연구)

  • Kim, Jin-Koo
    • Journal of Korean Ophthalmic Optics Society
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    • v.6 no.2
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    • pp.81-84
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    • 2001
  • This study can provide the accurate information on the treatment of visual acuity of a old ages by test of eye refraction state. The test was performed the visual acuity test by the object methods, and subjects was the over 45 old age. The eye types were 12% positive for emmetropia, 19% for myopia. and 69% for hyperopia, respectively. The abnormal refraction eyes were 3% positive for simple myopic astigmatism, 16% for myopic astigmatism, 14% for simple hyperopia, 5% for simple hyperopic astigmatism, 62% for mixed astigmatism, respectively. The axis of astigmatisms were 72% positive for against-the-rule astigmatism, 21% for with-the-rule astigmatism, 7% for ablique astigmatism, respectively.

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Acupuncture Treatment of a Child with Astigmatism and Visual Impairment (난시와 시력장애를 동반한 소아에 대한 침치료 1례 보고)

  • Heo, Jin;Jeong, Ju-Hyun;Lee, Byung-Ryul;Yang, Gi-Young;Kim, Young-Il
    • Journal of Acupuncture Research
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    • v.25 no.5
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    • pp.191-195
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    • 2008
  • Objectives : To estimate clinical effect of acupuncture treatment for astigmatism and visual impairment. Methods : Acupuncture treatment was performed on a young child, diagnosed as astigmatism and visual impairment from 23th May 2008 through 23th July 2008. Visual acuity and astigmatism were measured before and after treatment. Results : Visual acuity and astigmatism were improved after acupuncture treatment. Conclusions : This case demonstrates that acupuncture treatment has clinical possibilities for improving astigmatism and visual impairment and future studies will be required.

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A Study on the Accommodative Astigmatism of Near Vision (근거리 주시 시 조절성 난시에 대한 연구)

  • Lee, Hark-Jun
    • Journal of Korean Ophthalmic Optics Society
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    • v.16 no.3
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    • pp.327-331
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    • 2011
  • Purpose: The purpose of this study was an accurate grasp of the astigmatic change due to eyes accommodation on near vision and suggested problems occurring accommodative astigmatism using near glasses. Methods: 154 subjects(308eyes) from 20 to 40 years selected for this study who had many opportunity of near vision. First, far vision corrective refraction measured using the phoropter, and then both eyes opened simultaneously for maintaining the function of binocular put away dot chart 40 cm. One eye was fogging and the other eye measured near vision astigmatism axis and degrees astigmatism using cross cylinder, and then compared with far astigmatism. Results: Increased degree of astigmatism persons on near vision more than decreased or did not changed degree of astigmatism persons, which could affect visual acuity more than 0.75 diopters in 30 eyes with an increase of 9.7% of total subjects. Direct astigmatism and oblique astigmatism were increased on near vision. Astigmatic axes were rotated base in direction on both eyes and 66.9% of subjects were more than ${\pm}$5$^{\circ}$ rotation. Due to the rotation axis of astigmatism, residual astigmatism is expected to occur and expect to adversely affect the eyes. Conclusions: Long-term using the glasses without correction of increased astigmatic and rotated axis on near vision should occur new residual astigmatism and increase the asthenopia also. Considered to be taken astigmatic change on near vision during near refraction examination.

A Study of a Correction Effect of Astigmatism using Spherical RGP Lens (근시성 난시안에서 구면 RGP 콘택트렌즈의 난시교정 효과)

  • Ju, Seok-Hui;Park, Hae-Jung;Shin, Chul-Gun;Shim, Hyun-Seog
    • Journal of Korean Ophthalmic Optics Society
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    • v.8 no.2
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    • pp.85-89
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    • 2003
  • A tear lens formed by between back surface of spherical rigid gas permeable(RGP) contact lens and front surface of cornea shows an excellent correction effect of astigmatism. To study an effects of tear lens power using spherical RGP lens and therefore to utilize them in clinical procedures, we analyze a change of the total astigmatism, the cornea astigmatism, and the residual astigmatism, we derive the following conclusion. 1. Almost all refractive astigmatism below than 2.00D present fully corrected. Thereby resulting good visual acuity. Refractive astigmatism higher than 2.50D show under-corrected and apparent decrease of visual acuity if it is higher than 3.00D. 2. Amount of corneal astigmatism below than 2.50D show acceptable under-corrected while higher than 3.000 present unacceptable visual acuity. 3. An estimated residual astigmatism is not revealed as it is : but it is reduced when it incorporate to refractive astigmatism.

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Survey on the Refractive Status of Primary School Children with Subnormal Visual Acuity in Seoul (서울지역 초등학동 비정시안의 굴절상태에 대한 조사)

  • Kim, Hye Dong
    • Journal of Korean Ophthalmic Optics Society
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    • v.6 no.1
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    • pp.65-69
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    • 2001
  • To investigate the visual acuity of the primary school children. This study was researched visual acuity test using objective and subjective methods. 1. The eye types were 90.3% positive for myopia, 3.1% for emmetropia, 4.9% hyperopia, 1.7% for mired astigmatism. 2. The abnormal refraction eyes were 58.6% positive for simple myopia, 29.9% for myopic compound astigmatism, 5.1% for my optic simple astigmatism and 1.9% for simple hyperopia, 1.9% for hyperopic compound astigmatism, 1.3% for hyperopic simple astigmatism, 1.3% for mixed astigmatism. 3. The axis of astigmatism were 85.7% for astigmatism with-the-rule, 9.3% for astigmatism against-the-rule, 5.0% for astigmatism oblique. 4. On total myopic spheric power. the -0.50

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The effect of suture by absorbable material on corneal astigmatism after phacoemulsification

  • Yoo, Jae Ho;Lee, Sang Joon
    • Kosin Medical Journal
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    • v.33 no.3
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    • pp.318-327
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    • 2018
  • Objectives: To investigate the effect of absorbable suture on surgically-induced corneal astigmatism in 3.0-mm sclera tunnel cataract surgeries. Methods: Medical records of patients who underwent phacoemulsification cataract surgery using a 3.0-mm sclera tunnel incision made by a single surgeon were reviewed. Uncorrected distant visual acuity, corneal astigmatism and surgically-induced astigmatism were measured in 56 patients' eyes that underwent sclera tunnel cataract surgery with absorbable sutures (sutured group) and in 23 patients' eyes without sutures (unsutured group). Uncorrected visual acuity, intraocular pressure, slit lamp examination, and automated keratometry were evaluated preoperatively and at 3 days, 2 weeks, 4 weeks, and 8 weeks after cataract operation. Results: There were no significant differences in preoperative average uncorrected distant visual acuity of the two groups (sutured group: $0.79{\pm}0.64$, unsutured group: $0.68{\pm}0.72$, P = 0.145). Corneal astigmatism measured using keratometry in the sutured and unsutured group at postoperative day 3 were $2.27{\pm}2.12D$ versus $0.83{\pm}0.55D$ at (P < 0.001), a difference which had disappeared after 4 weeks. Surgically induced astigmatism using the Holladay and Vector methods showed similar outcomes, suggesting that the sutured group exhibited higher astigmatism compared with the unsutured group until 2 weeks post-surgery. Conclusions: TPatients undergoing scleral tunnel cataract surgery with absorbable sutures have greater surgically induced astigmatism, especially in the early postoperative period, compared with those without sutures. However, this surgically induced astigmatism due to absorbable sutures in scleral tunnel cataract surgery is temporary and disappears at 4 weeks post-surgery.

A Study of correlation between spherical refractive error and astigmatism (굴절이상도와 난시와의 관계 연구)

  • Lee, Jeung-Young;Kim, Jae-Do;Kim, Dae-Hyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.439-446
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    • 2004
  • Many studies have reported that retinal defocus cause and increase refractive error specially myopia. Uncorrected astigmatism may be one factor of retinal defocus factors. To understand the relationship between myopia and astigmatism 62 college students were participated in this study. Spherical refractive error and astigmatism were measured using N-vision 5001 autorefractor (Shinnippon). Co-relations between spherical refractive error and astigmatism were high both in the with-the-rule astigmatism group(r=0.53; ANOVA F=32.40, N=87, P<0.05) and oblique astigmatism group (r=0.53ANOVA F=5.14, N=15, P<0.001). However it was very low (r=0.09; ANOVA F=0.18, N=22, P<0.001)in the against-the-rule stigmatism group. In the total group co-relation was also high (r=0.56: ANOVA F=77.80, N=173, P<0.001). Uncorrected astigmatism may cause and increase spherical refractive error.

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