Predicting of Uncorrected Astigmatism from Decimal Visual Acuity in Spherical Equivalent

문병연,김상엽,조현국 한국광학회 2013 Current Optics and Photonics Vol.17 No.2

The purpose of this study was to determine the relationship between the spherical equivalent visual acuity (VA) and uncorrected astigmatism. On 108 emmetropic eyes, the spherical equivalent VA was measured for cross cylindrical lens (CC lens)-induced astigmatic eyes and the VA-astigmatism relation determined. On 158 astigmatic eyes, the spherical equivalent VA and corrected astigmatism were measured and the measured values were compared with the calculated values from the VA-astigmatism relation by correlation coefficient analysis. Subsequent to that, the relationship between spherical equivalent VA and uncorrected astigmatism was made. The relationship was fitted for an exponential equation. Correlation coefficient between calculated values by equation and measured values for astigmatic eyes was 0.991(p<0.01). The relationship between the spherical equivalent VA and the uncorrected astigmatism was decided as follows (spherical equivalent VA / uncorrected astigmatism): 1.0 / 0.25 D, 0.9 / 0.50 D, 0.8/ 0.75 D, 0.7 / 1.00 D, 0.6 / 1.25 D, 0.5 / 1.50 D, 0.4 / 2.00 D, 0.3 / 2.50 D, 0.2 / 3.00 D, 0.1 / 4.00D, and 0.05 / 4.75 D. In conclusion, the relationship table devised from this study is a useful reference for predicting uncorrected astigmatism by measurement of decimal VA in spherical equivalent.

자동포롭터 내부렌즈의 합성굴절력에 대한 신뢰도 평가

이형균,김소라,박미정 한국안광학회 2015 한국안광학회지 Vol.20 No.4

Purpose: To evaluate the reliability of refractive power by comparing the marked refractive power in an automatic phoropter and actually measured spherical/cylindrical refractive power. Methods: Actual refractive power of minus spherical lens and cylindrical lens in an automatic phoropter was measured by a manual lensmeter and compared with the accuracy of marked refractive power. Furthermore, combined refractive power and spherical equivalent refractive power of two overlapped lenses were compared and evaluated with the refractive power of trial lens. Results: An error of 0.125 D and more against the marked degree was observed in 70.6% of spherical refractive power of spherical lens which is built in phoropter, and the higher error was shown with increasing refractive power. Single cylindrical refractive power of cylindrical lens is almost equivalent to the marked degree. Combined spherical refractive power was equivalent to spherical refractive power of single lens when spherical lens and cylindrical lens were overlapped in a phoropter. Thus, there was no change in spherical refractive power by lens overlapping. However, there was a great difference, which suggest the effect induced by overlapping between cylindrical refractive power and the marked degree when spherical lens and cylindrical lens were overlapped. Spherical equivalent refractive power measured by using a phoropter was lower than that estimated by trial glasses frame and marked degree. The difference was bigger with higher refractive power. Conclusions: When assessment of visual acuity is made by using an automatic phoropter for high myopes or myopic astigmatism, some difference against the marked degree may be produced and they may be overcorrected which suggests that improvement is required. 목적: 자동포롭터의 표기 도수와 구면굴절력 및 원주굴절력 실측값을 비교하여 굴절력의 신뢰도를 평가하였다. 방법: 자동포롭터의 마이너스 구면렌즈 및 원주렌즈의 굴절력을 수동렌즈미터로 측정하여 표기도수와의 정확도를비교하였으며 두 렌즈가 중첩되었을 때의 합성굴절력과 등가구면굴절력을 시험렌즈와 비교 평가하였다. 결과: 포롭터에 내장되어 있는 구면렌즈의 구면굴절력은 70.6%가 표기도수와 0.125 D 이상의 오차가 발생하였으며, 굴절력이높아질수록 오차값도 증가하였다. 원주렌즈의 단일 원주굴절력은 표기도수와 거의 일치하였다. 포롭터에서 구면렌즈와 원주렌즈가 중첩되었을 때의 합성 구면굴절력은 단일렌즈 구면굴절력과 동일하여 중첩에 의한 구면굴절력의변화가 없음을 알 수 있었다. 그러나 구면렌즈와 원주렌즈가 중첩되었을 때의 원주굴절력은 표기도수와 큰 차이가있어 중첩에 의해 영향을 받는다는 것을 알 수 있었다. 포롭터를 이용하여 실측된 등가구면굴절력은 표기도수 및시험테를 이용한 등가구면굴절력에 비해 낮았으며 고도수일수록 더 낮았다. 결론: 고도의 근시안 또는 근시성 난시안에서 자동포롭터를 사용하여 시력검사를 하는 경우 표기도수와 차이가 발생하며 과교정이 될 것으로 보여 이에대한 개선이 필요할 것으로 보인다.

인공수정체 탈구에서 수술방법의 차이에 따른 술 후 결과 비교

선재홍,김재용,김명준,윤영희,차흥원,Jae Hong Sun,Jae Yong Kim,Myoung Joon Kim,Young Hee Yoon,Hung Won Tchah 대한안과학회 2014 대한안과학회지 Vol.55 No.2

Purpose: To compare clinical outcomes of various surgical methods of intraocular lens dislocation correction surgery. Methods: We retrospectively analyzed the medical records of patients who underwent intraocular lens dislocation correction surgery with and without vitrectomy by two seasoned surgeons, and compared postoperative best corrected visual acuity and spherical equivalent. Clinical outcomes of secondary intraocular lens insertion after primary intraocular lens removal and primary intraocular lens reposition were compared among the cases without vitrectomy. Results: Dislocated intraocular lens correction without vitrectomy showed better postoperative visual acuity compared to procedures with vitrectomy (0.35 ± 0.37 vs. 0.54 ± 0.18; t-test, p = 0.001), but there were no significant differences in spherical equivalent (1.30 ± 1.10 vs. 1.80 ± 1.57; p = 0.24) between cases with and without vitrectomy. In comparing primary intraocular lens reposition and secondary intraocular lens insertion among the cases without vitrectomy, the outcomes did not show significant differences in best corrected visual acuity (0.28 ± 0.40 vs. 0.40 ± 0.37; p = 0.38) or spherical equivalent (1.66 ± 1.43 vs. 1.07 ± 0.79; p = 0.19). In comparing secondary intraocular lens insertion into the capsular bag and fixation to the sclera, iris and iris sulcus, the outcomes did not show significant differences in best corrected visual acuity (p = 0.49) or spherical equivalent (p = 0.33). Conclusions: The various intraocular lens correction methods examined did not show clinically significant differences in best corrected visual acuity and spherical equivalent when performed by experienced surgeons, except for better postoperative best corrected visual acuity in cases without vitrectomy compared to cases with vitrectomy. J Korean Ophthalmol Soc 2014;55(2):196-201

연령에 의한 안광학 상수와 굴절이상의 변화도 분석

정미아,이혜정,정세준,강인산,송윤영 대한시과학회 2008 대한시과학회지 Vol.10 No.4

Purpose : We have investigated the vanatwn between ocular components and re(ractive error v.~lh various age groups between 20 to 69 years old. Methods : Refractive error and ocular components were measured in 100 adults (200 eyes) v.~th healthy eyes. Spherical equivalenl. corneal power and mean corneal radius were measured using a Canon RK-Fl autorefractor. Anterior chamber depth and axial length measurements were made using IOL Master. AUCR ratio was calculated by dividing axial length measurements by mean corneal radius. Power vector analysis was used to analyze the refractive error which is expressed with three vectors : M, Jo. J 15· Results : Measured Spherical equivalent values were -1.51±2.480(males -1.33± 2.070, females -1.63±2.670). and showed significant age groups dependence. Measured AUCR ratio values were 3.15±0.15(males 3.16±0.12. females 3.15±0.17). and showed significant age groups dependence. Prevalence of spherical equivalent were as follows : myopesOlleyes. 55.5%). emmetropes(49eyes. 24.5%). hyperopes (40eyes. 20%), and astigmatic eyes(89eyes, 44.5%). As increasing the age from 20s to 60s, M components of power vector analysis showed the change myopia to hyperopia(from -3.44±2.460 to 0.88±1.270). Jo components of power vector analysis changed with-the-rule(WfR) to against-the-rule(ATR)(0.41±0.67D for 20s and -0.01± 0.350 for 40s). J4s components of power vector analysis were -0.67±0.140 for 20s and 0.09±0.270 for 50s. ln J.,s components analysis. the cylinder axis observed near 135 degree for 20s and 45 degree for 50s. Linear regression analysis showed the strong negative correlation between axial length and spherical equivalent(r = -0. 73. p < 0.0001). The correlation between AUCR ratio and spherical equivalent showed the most strong negative dependence(r = -0.82, p < 0.0001). Conclusion : Prevalence of myopia showed 55.5%0lleyes) in 200 eyes. Refractive error showed the change from myopia to hyperopia and total astigmatism showed the change from with-the-rule to against-the-rule with increasing ages. Analysis of biometric data showed that AUCR ratio has the highest negative correlation with spherical equivalent.

도시와 농촌의 13세 어린이에 대한 굴절상태 분석

김덕훈,김정숙,Kim, Douk-Hoon,Kim, Jung-Sook 한국임상보건과학회 2017 한국임상보건과학회지 Vol.5 No.1

Purpose. To analyze the refractive status between urban and rural regions, of children in Korea, in the age group of 13. Methods. From October 2016 to January 2017, forty subjects( 20 male subjects, 20 female subjects; 13 years) were performed in refraction test using the Auto-Refraction. Myopia, hyperopia, astigmatism, and anisometropia were defined as spherical equivalent(SE)${\leq}-0.50$ diopters, SE ${\geq}+1.00D$, cylinder error ${\geq}0.75D$ and SE difference${\geq}1.00D$ between binocular eyes, respectively. Results. The refractive error by spherical equivalent among all subjects was myopia 76.25%, astigmatism 35%, emmetropia 16.25%, anisometropia 8.75%, and hyperopia 5%. The prevalence of myopia and astigmatism were much more common in urban than rural region although the difference was not statically significant. Emmetropia and astigmatism were much more common in rural region than urban although the difference was not statically significant. The prevalence of spherical equivalent was much common from -1.00 diopter to -4.00 diopter. On the other hand, the prevalence of myopia was much more than hyperopia. There was a statistical significance between OD and OS of rural region in the spherical equivalent power(p<.000). Also, There was a statistical significance between OD and OS of urban region in the spherical equivalent power(p<.004). Therefore, there was a significant statistical similarity between urban and rural regions on the OD and OS in the spherical equivalent power. On the other hand, There was a significant statistical similarity between urban and rural regions of the OD and OS in the astigmatism power(p<0.000). However, in the rural and urban regions there was not statistical significance in the OD and OS concerning the spherical equivalent power and astigmatism power (p>0.1). Conclusions. Myopia was the most common refractive error in Korea young children. while hyperopia was few. There was not a statistical significance as age between rural and urban at spherical equivalent power( P> 0.01). These results suggested that the analysis of the refractive status at young children can give the useful diagnosis data for the correction of visual acuity.

한국 어린이의 연령에 따른 굴절이상 분석

김덕훈,김대년,Kim, Douk-Hoon,Kim, Dae-Nyoun 한국임상보건과학회 2014 한국임상보건과학회지 Vol.2 No.4

Purpose. to describe the prevalence of refractive error according to aging in young children in South Korea. Methods : From July 2013 to June 2014, five hundred subjects( 250 male subjects, 250 female subjects; aged between 7 and 12 years) were performed in refraction test using the Auto-Refraction. Myopia, hyperopia, astigmatism, and anisometropia were defined as spherical equivalent(SE)${\leq}-0.50$ diopters, SE ${\geq}+2.00$ D, cylinder error ${\geq}0.75$ D and SE difference${\geq}1.00$ D between binocular eyes, respectively. Results. The refractive error by spherical equivalent among all subjects was myopia 80.41%, astigmatism 44.89%, emmetropia 18.27%, anisometropia 16.92%, and hyperopia 1.32%. The prevalence of myopia increased with age. but hyperopia was decrease. Myopia and astigmatism were much more common in male than females although the difference was not statically significant. Emmetropia and hyperopia were much more common in female than males although the difference was not statically significant. The prevalence of spherical equivalent was much common from -1.00 diopter to 0.99 diopter. On the other hand, the prevalence of myopia was much more than hyperopia. There was a statistical significance between 9 year and 10 year of female in the spherical equivalent power(p>0.05). In all another group of age, there was not a statistical significance as aging in spherical equivalent power(p>0.5). However, there was a statistical significance between male and female as age in the spherical equivalent power(P>0.01). Conclusions: Myopia was the most common refractive error in Korea young children, while hyperopia was decreased after 7 years. There was a statistical significance as age between male and female at spherical equivalent power(P> 0.01). these results suggested that the analysis of the refractive error as age at young children can give the useful diagnosis data for the correction of visual function.

The Effects of Pinhole on Decimal Visual Acuity, Spherical Equivalent Refractive Error, and Astigmatism

Hyung-Sup Shin,Jun-Gui Jang 대한시과학회 2016 대한시과학회지 Vol.18 No.4

목 적: 핀홀의 크기를 변경하면서 피검자의 소수시력을 측정하였으며, 핀홀의 크기가 시력, 등가구면 굴 절이상, 난시도에 주는 영향을 연구하였다. 방 법: 성인 118명, 평균나이 22.7±5.9세를 대상으로 핀홀의 크기를 0.5 ~ 3.0 mm로 하고, 굴절이상에 따른 소수시력을 측정하였다. 동공크기에 따른 시력을 계산하여, 측정된 소수시력과 비교하였다. 결 과: 핀홀의 크기가 감소하면, 소수시력이 고도근시(-6.96±0.83 D)와 중등도근시(-4.30±0.83 D)에 서는 크게 증가했으며, 약도근시(-1.63±0.64 D)는 핀홀크기 1.0 mm에서 정점을 나타냈다. 정시 (-0.11±0.37 D)와 원시(1.88±1.63 D)는 약간 감소하였다. 동공의 크기가 감소하면 종구면수차와 종색수차 가 서서히 감소하고, 피사체심도가 소수시력에 주는 영향은 일정하였으나, 회절이 급격히 증가하여 정시에 대해 계산한 시력은 동공크기 1.5 mm 이하에서 감소했다. 근시는 회절과 수차보다 등가구면 굴절이상의 영 향이 커서, 동공크기 1.0 mm까지 계산한 시력이 직선적으로 증가했다. 근시성 고도난시(C= -2.73±0.63 D), 근시성 약도난시(C= -1.93±0.39 D), 원시성 난시(C= 1.29±0.72 D)에서는 시력의 변화가 등가구면 굴절이상의 크기가 유사한 근시 또는 원시와 같았다. 결 론: 핀홀의 크기가 감소할 때, 정시와 원시는 수차가 감소하지만, 회절이 증가하여 소수시력이 약간 감소하였다. 피사체심도가 소수시력에 미치는 영향은 핀홀크기에 관계없이 일정하였다. 근시는 등가구면 굴 절이상의 영향이 커서 소수시력이 크게 증가하였다. 난시의 소수시력은 난시도보다 등가구면 굴절이상의 영 향을 주로 받기 때문에, 핀홀이 난시도를 개선했다고 할 수 없다. Purpose: While changing the pinhole size, the decimal visual acuity of subjects was measured. The effects of pinhole size on visual acuity, spherical equivalent refractive error, and astigmatism are studied. Methods: 118 adult subjects participated in this study. The mean age of subjects was 22.7±5.9 years. The decimal visual acuity was measured as a function of pinhole size (0.5 ~ 3.0 mm) and refractive error. The decimal visual acuity according to the pupil size was calculated and compared with the measured visual acuity. Results: When the pinhole size was reduced, the decimal visual acuity of high myopia (-6.96±0.83 D) and mild myopia (-4.30±0.83 D) was significantly increased. The visual acuity of low myopia (-1.63±0.64 D) showed a maximum at pinhole size 1.0 mm. The visual acuity of emmetropia (-0.11±0.37 D) and hypermetropia (1.88±1.63 D) was slightly reduced. If the pupil size is reduced, the longitudinal spherical aberration and the longitudinal chromatic aberration were gradually reduced and the effect of the depth of field on the visual acuity was constant, but the diffraction was largely increased. Therefore, the calculated decimal visual acuity of emmetropia decreased below pupil size 1.5 mm. Up to pupil size 1.0 mm, the calculated visual acuity of myopia increased linearly because the influence of spherical equivalent refractive error is larger than that of diffraction and aberration. The changes of the decimal visual acuity of myopic high astigmatism (C= -2.73±0.63 D) and myopic mild astigmatism (C= -1.93±0.39 D) were equal to that of the myopia of similar spherical equivalent refractive error. Also that of hyperopic astigmatism (C= 1.29±0.72 D) was equal to that of the hypermetropia of similar spherical equivalent refractive error. Conclusions: While decreasing the pinhole size, the visual acuity of emmetropia and hypermetropia decreased slightly because the diffraction increases largely and the aberrations decrease. Effect of the depth of field on decimal visual acuity was constant regardless of the pinhole size. The visual acuity of myopia increased largely due to the influence of spherical equivalent refractive error. The astigmatism can not be decreased by the pinhole because the spherical equivalent refractive error affects mainly on the visual acuity.

굴절이상과 안광학 상수의 상호연관성에 관한 연구

정미아,이혜정,정세준,송윤영,최정훈 대한시과학회 2008 대한시과학회지 Vol.10 No.3

목 적 : 굴절이상도 및 굴절이상과 안광학 상수의 상호연관성을 알아보기 위하여 수행되 었다. 방 법 : 안질환이 없는 건강한 젊은 성인 68명, 68안(우안)을 대상으로 Topcon KR-8800 을 사용하여 등가구면 굴절력, 각막 굴절력, 각막 곡률반경을 측정하였다. 전방 깊이, 수정체 두께, 유리체 깊이, 안축장 길이는 A-Scan Ultrasonography를 사용하여 측정하였으며, AL/CR비는 안축장 길이를 평균 중심 각막 곡률반경으로 나누어 계산하였다. 결 과 : 등가구면 굴절력은 -3.55±2.84D(남자 -3.73±3.21D, 여자 -3.40±2.55D)로 남녀사이의 유의한 차이가 없었다. 전체 68안 중 근시 60안(88.24%), 정시 6안(8.82%), 원 시 2안(2.94%)으로, 등가구면 굴절력은 근시 -4.02±2.69D, 정시 -0.33±0.13D, 원시 +0.88±0.18D로 측정되었다. 원주 굴절력이 0.75D 이상은 35안(51.47%)으로, 직난시 33안 (94.29%), 사난시 2안(5.71%)으로 나타났으며 전난시와 각막난시는 높은 음의 상관관계를 보였다(r = -0.84, p < 0.0001). 굴절이상에 의한 AL/CR비는 정시 2.93±0.02, 근시 3.12± 0.14, 원시 2.87±0.01로 측정되었으며, 등가구면 굴절력과 가장 높은 상관관계를 나 타냈다(r = -0.88, p < 0.0001). 결 론 : 굴절이상은 안축장 길이에 의한 것이 중요한 원인으로 본 연구에서도 안축장 길 이는 등가구면 굴절력과 높은 음의 상관관계를 보였으며, AL/CR비가 등가구면 굴절력과 가 장 높은 음의 상관관계를 보여 선행연구와 일치하였다. 난시분포는 도난시와 사난시에 비해 직난시가 많은 것으로 나타났으며 전난시와 각막난시는 높은 음의 상관관계를 보여 전난시의 중요한 원인이 각막난시에 의한 것임을 알 수 있었다. Purpose : This study investigates the prevalence of refractive error and to study the ocular biometric correlates of refractive error. Methods : Refractive error and ocular biometry were measured in 68 adults(68 eyes) with healthy eyes. Spherical equivalent refraction, corneal power and mean corneal radius were measured using a Topcon KR-8800 autorefractor. Anterior chamber depth, crystalline lens thickness, vitreous chamber depth and axial length measurements were made using A-scan ultrasonography. AL/CR ratio was calculated by dividing axial length measurements by mean corneal radius. Results : Spherical equivalent refractions were measured by -3.55±2.84D(males -3.73± 3.21D, females -3.40±2.55D), and not differ significantly between males and females. Prevalence of spherical equivalent refraction were as follows : myopes (60eyes, 88.24%), emmetropes(6eyes, 8.82%), hyperopes(2eyes, 2.94%). Groupaveraged spherical equivalent refractions were as follows : myopes(-4.02± 2.69D), emmetropes(-0.33±0.13D), hyperopes(+0.88±0.18D). Astigmatism of at least 0.75D was evident in 51.47%(35 eyes) of the subject cohort. Astigmatism for these groups was as follows : with-the rule astigmatism(33eyes, 94.29%), oblique astigmatism (2eyes, 5.71%). Regression analysis of corneal toricity against ocular astigmatism revealed a strong negative correlation(r = -0.84, p < 0.0001). AL/CR ratio against refractive error were measured by emmetropes(2.93±0.02), myopes(3.12±0.14), and hyperopes(2.87±0.01). Linear regression analysis showed that AL/CR ratio correlated most closely with spherical equivalent refraction(r = -0.88, p < 0.0001). Conclusion : A strong correlation was found between axial length and spherical equivalent refraction and the principal factor in refractive error is axial length. Analysis of biometric data has shown that AL/CR ratio has the highest negative correlation with spherical equivalent refraction, thus supporting previous studies. With-the-rule astigmatism was more prevalent than other astigmatism in this study. A strong negative correlation was found between corneal toricity and astigmatism, the principal factor in ocular astigmatism is corneal toricity.

한국인 노안 굴절상태 분석

김덕훈,이민호,Kim, Douk-Hoon,Lee, Min-Ho 한국임상보건과학회 2019 한국임상보건과학회지 Vol.7 No.2

Purpose. This study was the analyze the refractive status of presbyopia in Korea. Methods. The subjects was from November 2018 to October 2019, two hundred thirty four subjects( 117 male subjects, 117 female subjects; from 40-year old to 88-year old ) were performed in refraction test using the Auto-Refraction(Speed -K model, Japan). The myopia, hyperopia, astigmatism, and anisometropia were defined as spherical equivalent(SE)≤-0.50 diopters, SE ≥+1.00 D, cylinder error ≥0.75 D and SE difference≥1.00 D between binocular eyes, respectively. Results. The refractive status by spherical equivalent among all subjects was myopia 61.43%, astigmatism 86.86%, emmetropia 19.18%, anisometropia 12.07%, and hyperopia 18.54. The prevalence of myopia and astigmatism were much more common in male. However, The hyperopia and astigmatism were much more common in female. The prevalence of spherical equivalent was much common from -0.50 diopter to -5.00 diopter. On the other hand, the prevalence of astigmatism and myopia was much more than hyperopia in all subjects. There was a statistical significance between OD and OS of the female and male in the spherical equivalent power(p<.000). However, there was not statical significant between female and male of OD and OS in the spherical equivalent power(p<.070). On the other hand, The prevalence of againest axis in astigmatism was more common in all subjects. In ADD power for the near vision correction, the female was much more diopter than male. Conclusions. These results suggested that the analysis of the refractive status on the presbyopia in Korea can give the useful diagnosis data for the correction of visual acuity at near distance.

7세부터 9세 사이의 한국인 어린이의 굴절 이상

김덕훈,Kim, Douk-Hoon,Alberto, Mercedita O. 한국임상보건과학회 2014 한국임상보건과학회지 Vol.2 No.3

Purpose. To analysis the refractive error in 7-9 year-old Korea children. Methods. From July 2013 to June 2014, two hundred eighty two subjects were performed in refraction test using the Auto-Refractometry. Results. The refractive error by spherical equivalent among all subjects was myopia 47.58%, emmetropia 42.35%, astigmatism 32.33%, and hyperopia 8.76%. Myopia was more common in female than males although the difference was not statically significant. The axis of astigmatism was with the rule in 65%, against the rule in 31.5%, and oblique in 3.5% There was a statistical significance between 7 year and 9 year of male in the spherical equivalent power(p=0.010). Also there was a statistical significance between 7 years and 9 years of female in the spherical equivalent power(p=0.036). However, there was not a statistical significance between male and female in spherical equivalent power(p>0.5). Conclusions. In this study, myopia was the most common refractive error. On the other hand, The prevalence of the axis of astigmatism was the with- the- rule. The spherical equivalent of refractive error was similar results between male and female. However The refractive error was different style with aging. these data suggested that the analysis of the refractive error at young children can provide the information of useful diagnosis for the correction of visual acuity.