• Journal of Korean Ophthalmic Optics Society
• /
• v.7 no.2
• /
• pp.47-54
• /
• 2002

This study as performed to survey symmetrical and asymmetrical astigmatism among 1,100 patients(2,200eyes) who were prescribed with spectacles. Of the 2,200 eyes, 59.3%(1,305 eyes) had astigmatism. Among all patients, 21.4%(235 patients) had unilateral astigmatism, 48.6%(535 patients) had bilateral astigmatism. In 1,070 eyes(535 patients) with the bilateral astigmatism, the orientation of astigmatism were 61.2% for with-the-rule astigmatism, 24.7% for against-the-rule astigmatism and 14.1% for oblique astigmatism. On the astigmatic power, -0.25~-0.50D was 47.5%, -0.75~-1.00D was 29.9%. Symmetrical astigmatism was 83.4% of the bilateral astigmatism. Asymmetrical astigmatism was 16.6% of them. From 41 to 50 years of age, 45.4% of the age had symmetrical astigmatism, 14.3% had asymmetrical astigmatism. Types of the left and the right eye in symmetrical astigmatism consisted of with-the-rule astigmatism and with-the-rule astigmatism(65.5%), against-the-rule astigmatism and against-the-rule astigmatism(25.3%), oblique astigmatism and oblique astigmatism(5.6%), etc. In asymmetrical astigmatism, with-the-rule astigmatism and oblique astigmatism was 23.6%, oblique astigmatism and with-the-rule astigmatism was 20.2%. As the results of this study, most of spectacles wearers had bilateral astigmatism that was more than unilateral astigmatism. Symmetrical astigmatism was 5 times more than asymmetrical astigmatism with no sex differences. Especially, symmetrical and asymmetrical astigmatism were more in forties than in other age groups. Over the half of symmetrical astigmatism was with-the-rule astigmatism in the left eye and with-the-rule astigmatism in the right eye. These findings will be used in prescriptions for more comfortable vision.

• Journal of Korean Ophthalmic Optics Society
• /
• v.6 no.1
• /
• pp.71-76
• /
• 2001

In this study, the variation of astigmatism axis according to the age was studied 4227 eyes of healthy eyes. The refractive errors were measured by objective and subjective refraction. The astigmatism among the total eyes was 76.5%. With-the-rule, against-the-rule and oblique astigmatism were 51.4%, 31.7% and 16.9%, respectively. The frequency of with-the-rule was the highest and against-the-rule was the lowest of all the astigmatism in the refractive error. In relation to the age and astigmatism, the with-the-rule was 68.3% in the 10's age group which was the highest among the astigmatism and the against-the-rule was 10.3% in the 50's age group and upward which was the lowest among the astigmatism. The difference in the with-the-rule and against-the-rule ratio was a little in the 30's age group. As they aged, the tendency of the with-the-rule was increased between 10's and 20's age group continually. And the tendency of the against-the rule was increased between 30's and 50's age group and upward. There was a decrease in with-the-rule and an increase in against-the-rule, with the age increase. The oblique astigmatism relationship to age could not be determined.

• Journal of Korean Ophthalmic Optics Society
• /
• v.12 no.2
• /
• pp.47-59
• /
• 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.

• Journal of Korean Ophthalmic Optics Society
• /
• v.7 no.2
• /
• pp.41-45
• /
• 2002

To study the ametropia and the sort of glasses, especially progressive multifocal lens, for near purpose on Middle aged & Manhood. 500 adults were tested by the object and subject methods. Among the 500 adults, myopia is 22.4%, hyperopia is 61.4%, and emmetropia is 16.2%, respectively. In test of astigmatism, the amount of astigmatism for the age of forty one to under forty five with-the rule is 28%, the amount of astigmatism against-the rule is 43% and the amount of astigmatism with oblique is 11%, respectively. Whereas, the amount of astigmatism for the age of fifty six to under sixty with-the rule is 10%, the amount of astigmatism against-the rule is 71% and the amount of astigmatism with oblique is 19%, respectively. With-the-rule decreased with increasing age while against-the-rule increased with increasing age. The oblique astigmatism relationship to age could not be determined. The ratio of the progressive multifocal lens was 67.3% for male and 35% for female.

• Journal of Korean Ophthalmic Optics Society
• /
• v.19 no.3
• /
• pp.377-382
• /
• 2014

Purpose: To investigate the effect of anterior, posterior corneal astigmatism and total corneal astigmatism on posterior corneal astigmatism by analyzing correlation. Methods: Participants were 31 patients (31 eyes) without corneal disease at the age range of 22 to 28 who had visited hospital to receive corneal refractive surgery. The total corneal astigmatism and anterior and posterior corneal astigmatism were measured using a rotating scheimpflug camera before surgery. The magnitude of astigmatism was calculated with the difference between the meridian of the steep refractive power and the flat, and With-The-Rule and inverse astigmatism were divided according to the direction of the meridian that was the steepest. Results: The averages of total corneal astigmatism and anterior and posterior astigmatism were found to be $1.13{\pm}0.76D$, $1.51{\pm}0.84D$, and $-0.59{\pm}0.17D$. The magnitude of posterior corneal astigmatism was distributed between -1.0 D and -0.25 D in all the subjects, and when the magnitude of total corneal astigmatism was set as 100, the magnitude of anterior corneal astigmatism was $142.9{\pm}29.9%$. Total corneal astigmatism indicated the highest correlation with the magnitude of anterior astigmatism (y = 0.871x-0.184, $R^2=0.982$) and high negative correlation with posterior astigmatism (y = -2.974x-0.184, $R^2=0.698$). All the subjects' anterior and posterior corneal astigmatism was classified into With-The-Rule. Conclusions: Anterior and posterior corneal astigmatism in the subjects in their 20's showed the magnitude of -3.8 D in 0.2 D and -0.25 D in -1.0 D separately, and both anterior and posterior astigmatism indicated a high percentage of With-The-Rule.

• Journal of Korean Clinical Health Science
• /
• v.10 no.1
• /
• pp.1553-1558
• /
• 2022

Purpose: The aim of this study was to determine the association between stigmatism and amblyopia. Methods: It was a hospital based, cross-sectional retrospective study conducted in Nepal Eye Hospital. Medical record of amblyopic children aged 13 years or younger from were reviewed. Children with amblyopic eyes due to simple astigmatism were included. Relation between depth of amblyopia with magnitude and types of astigmatism, orientation of axis was determined. Out of 139 amblyopic eyes of 82 children, 93 were simple myopic astigmatism and remaining 42 were simple hyperopic astigmatism. Results: Mean age of patients was 7.38±2.61 years. Visual acuity improved by at least one line in Snellen chart in 4/5th of eyes after astigmatic correction. Moderate amblyopia was found to be present in 45% eyes while severe amblyopia in 16% of eyes. With the rule astigmatism was found to be present in 88% eyes. Mean astigmatism was 2.47±0.98D and majority of eyes (67.7%) had high astigmatism. Depth of amblyopia was not associated with magnitude of astigmatism (p > 0.05) but number of lines improved with astigmatic correction was correlated with the magnitude of astigmatism (p < 0.001). Risk of amblyopia is more in high myopic astigmatism. Conclusion: Presenting age of amblyopic children was late in Nepal. Depth of amblyopia was not associated with magnitude of astigmatism.

• Journal of Korean Ophthalmic Optics Society
• /
• v.12 no.2
• /
• pp.25-36
• /
• 2007

We researched the change of astigmatism power when the fixation point moved from far distance to near distance. Astigmatism power was measured by using both eyes open-view auto-refractometer. We divided the ages between 5 and 67 years old into 12 groups with 1,598 healthy eyes(male-698 eyes and female-900 eyes) without eyes problems and experiences of eyes operations. The mean power in far astigmatism showed that with-the-rule of the total astigmatism: -0.79D, with-the-rule of the corneal astigmatism: -1.07D and against-the-rule of the residual astigmatism : -0.79D were found most respectively. The correlation between cornea astigmatism and total astigmatism was y=0.7493 x + 0.5661 r=0.6510, residual astigmatism and total astigmatism was y=0.248 x - 0.5926 r=0.2598 and corneal astigmatism and residual astigmatism was y=-0.4439 x - 0.1813 r=-0.5551 in the far distance. The mean power in near astigmatism showed that with-the-rule of total astigmatism : -0.92D, with-the-rule of corneal astigmatism : -1.12D, against-the-rule of residual astigmatism : -0.87D were found most respectively. In the near distance, The correlation between corneal astigmatism and total astigmatism was y=0.6872 x + 0.5934 r=0.6204, residual astigmatism and total astigmatism was y=0.303 x - 0.6066 r=0.3165, corneal astigmatism and residual astigmatism was y=-0.46 x - 0.0626 r=-0.5322. When the fixation point moved far distance to near distance, the differences of power according to the type of astigmatism were total astigmatism: $-0.07D{\pm}0.44D$, corneal astigmatism: $-0.04D{\pm}0.54D$ residual astigmatism:$0.01D{\pm}0.53D$. Most of astigmatism refractive power was increased except for oblique-the -astigmatism. When the fixation point moved far distance to near distance, the change of astigmatism refractive power showed total astigmatism: 540 eyes(33.7%), corneal astigmatism: 638 eyes(39.9%), residual: 841 eyes(52.6%).

• Journal of Korean Clinical Health Science
• /
• v.9 no.1
• /
• pp.1478-1485
• /
• 2021

Purpose. To analysis of astigmatism in Korean adults from 20 to 29 years old. Methods. From January 2019 to February 2020, one hundred two subjects were performed in refraction test using the Auto-Refractometry. Results. In the type of astigmatism based on refractive error, the male's right eye was 4.26% simple myopic astigmatism and 95.74% complex myopic astigmatism, and the left eye was 2.22% simple myopic astigmatism and 97.78% complex myopic astigmatism. However, in the female's right eye, simple myopic astigmatism was 2.27%, complex myopic astigmatism was 97.73%, and left eye was simple myopic astigmatism was 2.17%, complex myopic astigmatism was 97.83%. The types of astigmatism in men and women similar to other. The mean refractive astigmatism values were -0.922±-0.798 diopter and -0.877±-0.707 diopter for male right and left eye, and -0.765±-0.599 diopter and -0.853±-0.586 diopter for female. On the other hand, the refraction values of the right and left eyes of men and women have statistical significance(p=0.000). The mean power comparative between refractive astigmatism and corneal astigmatism power were -0.186±-0.745 diopter, -1.091±-0.589 diopter in male and -1.140±-0.593 diopter, -1.140±-0.534 diopter in female. Therefore, the mean power values of the refractive astigmatism and corneal astigmatism of men and women were statistical significance(p=0.000). At the 0.75 diopter or more, which can have clinical symptoms of astigmatism power, males have 60.86% and 72.09% of the right and left eyes, and females have 47,64% and 60.10% of the right and left eyes. At 0.75 diopter or more, which can have clinical symptoms of corneal astigmatism power, males have 68.75% and 74% of the right and left eyes, and females have 86.50% and 82.35% of the right and left eyes. In the type of astigmatism axis, both men and women had a high frequency of the rule astigmatism. However, men had a high frequency of against-the-rule astigmatism and women showed a high frequency of oblique astigmatism. Conclusions. In this study, the complex myopic astigmatism and with-the rule astigmatism was the most common of all subjects. However, there was a statistical significance between right and left eyes of all subjects. The corneal astigmatism was higher refractive values in both males and females than refractive astigmatism. This study suggests that the analysis of the astigmatism can provide the useful diagnosis information for the correction of visual acuity.

• Journal of Korean Ophthalmic Optics Society
• /
• v.6 no.2
• /
• pp.81-84
• /
• 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.

• Journal of Korean Ophthalmic Optics Society
• /
• v.5 no.1
• /
• pp.117-123
• /
• 2000

In this study, total astigmatism and corneal astigmatism were studied 328 eyes of healthy Korean for astigmatism. Total astigmatism was measured by fogging-and-dial technique, and corneal astigmatism was measured with Topcon OM-4 keratometer. Residual astigmatism was determined by a discrepancy between total and corneal astigmatism. The results were as follows: As they aged, there were a statistically significant changes in total and corneal astigmatism but not in residual astigmatism. And the amount of with-the-rule total and corneal astigmatism had a tendency to decrease, but residual astigmatism had no changes. From 30 years, total astigmatism showed a tendency to become against the rule. The average diopteric value was +0.342D in total astigmatism. +0.920D in corneal astigmatism and -0.579D in residual astigmatism.