• Journal of Korean Ophthalmic Optics Society
• /
• v.13 no.1
• /
• pp.107-112
• /
• 2008

urpose: This thesis is a study the Night myopia was surveyed by Subjective refraction and Objective refraction (Dark retinoscopy), and analyzed the relationship between them. It also looked at the relation between Night myopia and pupil size. Methods: 82 adult subjects (ages of 19 to 44, 44 males and 38 females) were examined by Subjective refraction and Objective refraction in the light place. Then Night myopia and pupil size were examined by Subjective refraction and Objective refraction in the dark again. The Statistics were analyzed by SPSS (Statistical Package for Social Science). Results: As the subjects became younger, the observed Night myopia was getting higher in both Subjective refraction, $x^2$=219.48 (p<0.01) and Objective refraction, $x^2$=241.98 (p<0.01). The relationship was statistically significant by showing large pupil size, $x^2$=151.74 (p<0.01). In Objective refraction, as pupil size became larger in the dark place, so did Night myopia, $x^2$=84.27 (p<0.01), reaching a statistically significant correlation, however, the correlation was low in Subjective refraction. In Subjective refraction, observed Night myopia was 73%, 64 examples of 88 examples, a standard of 0.96${\pm}$0.4584D in ${\pm}$0.25D, in male examples, and it was 64%, 49 examples of 76 examples, a standard of 1.01${\pm}$0.4509D in ${\pm}$0.25D, in female examples. In Objective refraction, it was 48%, 42 examples of 88 examples, in standard of 0.85${\pm}$0.4651D in ${\pm}$0.25D, in male examples. And it was 71%, 54 examples of 76 examples, in standard of 0.96${\pm}$0.4133D in ${\pm}$0.25D, in female examples. Conclusions: Night myopia which is measured by both methods, observed as $x^2$=265.35 (p<0.01) and showed a large relationship. The correlation between the two refractions suggests that observed night myopia diopter by Subjective refraction could be used as correction of night myopia.

• Journal of Korean Ophthalmic Optics Society
• /
• v.10 no.1
• /
• pp.35-40
• /
• 2005

Subjective and objective visions were measured on young adults(mean 21 yrs, 126 eyes) who were free of any ocular diseases and laser surgery and none wore contact lenses. The aim of this study was to investigate the diurnal variation of vision through subjective and objective measurements. Subjective visual acuity were measured at 5 m three times a day, morning(8:00 AM-10:00 AM), noon(12:00 PM-2:00 PM) and afternoon(4:00 PM-6:00 PM). The instrument used for objective refraction right after visual acuity measurement was Nvision-K 5001(shin-nippon) which unique in being able to disregard subject's accommodation because of its unrestricted viewing conditions. Also, we measured that three times and then calculated the average values. The result showed that an average subjective visual acuity in the morning, noon, afternoon were 0.256(${\pm}0.263$), 0.266(${\pm}0.276$), 0.242(${\pm}0.249$) respectively. Average spherical equivalent power in objective refraction of right eyes showed -3.416 D(${\pm}2.907$), -3.359 D(${\pm}2.735$), -3.297 D(${\pm}2.709$) respectively and dioptric power was decreased from morning to afternoon. Vision changed throughout the day in both subjective and objective measurements nevertheless its variations were statistically insignificant(p<0.05). Therefore it does not seem to matter of time for either visual acuity test or refraction.

• Journal of Korean Ophthalmic Optics Society
• /
• v.15 no.1
• /
• pp.79-85
• /
• 2010

Purpose: We studied the relationship between subjective and objective deviating angle. Methods: Those who were diagnosed with strabismus among the patients who had no systemic diseases that fifty-one subjects (Male; 21, Female; 30) were measured between seven to sixty three years, evaluated to alternate cover test after AR/K (Canon RK-FI, Japan) and retinoscope measured refractive errors. Objective deviating angle was measured using prism bar; and subjective and objective deviating angles were measured and compared using the synoptophore. Results: For the correlation between subjective and objective deviating angles. The differences were $2.6{\pm}2.5{\Delta}$, between subjective deviating angle measured using synoptophore and objective deviating angles measured using synoptophore were $0.7{\pm}1.4{\Delta}$, the average with each other were $1.7{\pm}1.8{\Delta}$, with all the differences highly significant. Conclusions: We thought not only reduced angle of deviating errors and identified the significance in the correlation between subjective and objective deviating angles but also considered to be useful in determining deviating angle of patient with strabismus.

• Journal of Korean Ophthalmic Optics Society
• /
• v.18 no.3
• /
• pp.279-289
• /
• 2013

Purpose: To evaluate the changes of refractive power when worn soft contact lenses were temporarily removed. Methods: 91 soft contact lens wearers (15 males and 76 females; total 182 eyes) from 17 to 39 years of age (average: $24{\pm}4.8$ years) were participated. Objective and subjective refraction, and corneal radius were measured at 0, 30, 60 and 90 min after lens removal. The changes in refractive power were evaluated between measurements over time. The other parameters such as types of lenses, fitting and wearing conditions were also assessed. Results: Objective refraction, subjective refraction and corneal radius were significantly changed according to measured time (p<0.0001). A moderate myopic shifts was observed at the beginning (30 min after lens removal) and a slight myopic shift at the late of measurement (60 min to 90 min after lens removal). There are no significant differences between lens types, fitting states, wearing time, wearing days and sleeping time in the previous day. However, there was significant interaction in changes for corneal radius between measuring time and lens type (p=0.017), fitting state (p=0.019), and sleeping time prior to the test (p=0.010). Conclusions: Time to reach refractive and corneal radius stability after contact lens removal revealed at least more than 60 min, regardless of types of lenses, fitting and wearing conditions. Therefore, refraction for correction should be performed after waiting for more than that time as possible.

• Journal of Korean Ophthalmic Optics Society
• /
• v.6 no.2
• /
• pp.105-109
• /
• 2001

The investigate of preschool children at 7-year-old at three kindergartens in Iksan was done by the naked visual acuity, the refractive state and cover-uncover test. Total 246 eyes were examined by the objective and subjective methods. The results were as follows: 1. Among the 246 eyes, the naked visual acuity of below the average 0.7 was 64 eyes(26%). 2. As to the distribution of refractive errors, myopic eyes and hyperopic eyes were 26.55% and 26.55%, respectively. 3. As to the type of astigmatisms, with the rule was 85.8%, against the rule was 8.9% and oblique was 5.3%. 4. The percentage of preschool children who had been tested was 13.8%. 5. In test none of children were the phoria.

• Journal of Korean Ophthalmic Optics Society
• /
• v.16 no.3
• /
• pp.265-272
• /
• 2011

Purpose: The clinical usefulness of rotation evaluation using objective refraction in toric soft lenses fitting was investigated. Methods: Toric soft lenses were fitted for 32 subjects (64 eyes; mean age of 24.69 ${\pm}$ 1.65 years) with astigmatism and both eyes of each subject were fitted with toric soft lenses. Objective refraction-based lenses rotation was evaluated from refraction and over-refraction data by indirect calculating technique. These calculated data were compared with the measured data from slit lamp with direct measuring technique. Results: Orientation of toric soft lenses around zero position (within ${\pm}$ 5$^{\circ}$ vertical line) was investigated. The orientations to the direction of nose of measured and calculated values were 69.78% and 63.64%, respectively, which showed similar values between two techniques. Agreement frequency between measured and calculated values in the magnitude of lenses rotation 54.69% and 82.82% for 10$^{\circ}$ and 20$^{\circ}$ of vertical line, respectively. The 95% limits of agreement between calculation and measurement were from -10.08$^{\circ}$ to 12.65$^{\circ}$, and mean difference was 1.29$^{\circ}$ within ${\pm}$ 10$^{\circ}$. The result showed there was no significant difference (p = 0.1984) and high correlation (r = 0.56, p = 0.0004) between two techniques. But the 95% limits of agreement was widen in ${\pm}$ 20$^{\circ}$ of vertical line. The magnitude of lens rotation between two methods was 9.66 ${\pm}$ 6.16$^{\circ}$, 16.17 ${\pm}$ 12.38$^{\circ}$ and 10.58 ${\pm}$ 12.02$^{\circ}$ for normal, loose and tight fitted conditions. Conclusions: From the results with smaller difference between two techniques, it was found that higher availability of subjective over-refraction data can be used as a supplementary tool for subjective refraction. An application using objective refraction with direct measuring could be provide high success in prescription on toric soft lenses.

• Journal of Korean Ophthalmic Optics Society
• /
• v.15 no.4
• /
• pp.367-372
• /
• 2010

Purpose: The purpose of this study was to provide useful information for evaluating the sensory function of patients with strabismus by identifying the distribution of anomalous retinal correspondence (ARC) and normal retinal correspondence (NRC) by the degree of refractive errors and deviation angles. Methods: Objective refraction (AR/K, Cannon RK-F1, Japan) and subjective refraction tests were performed on 56 subjects (male: 26, female: 30) by an examiner; objective deviation angle was measured using synoptophore (OCULUS Synoptophore, Germany) with subject' eyes fully corrected for distance, and then subjective deviation angle was measured. Results: In all groups with refractive errors, the number of ARC was larger than that of NRC(67%). Particularly, it was largest in groups with myopia (71%), and in all groups, the number of UARC was larger than that of HARC. In groups with anisometropia, although the numbers of NRC and ARC were same, the number of UARC was larger than that of HARC as in other groups. In the distribution of NRC and ARC by deviation angle, the number of NRC was larger than that of ARC (46%) only at microstrabismus (0 ~ ${\pm}10{\triangle}$). Conclusions: Normal retinal correspondence were the most emmetropia in the retinal response were much higher than in the more hyperopia than the retinal correspondence were more myopia. In addition, the smaller the angle of retinal correspondence Normal over many, but overall, respectively.

• 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 the Korea Academia-Industrial cooperation Society
• /
• v.19 no.8
• /
• pp.353-359
• /
• 2018

In this study, the performance between subjective refraction and open-field/closed view autorefraction was estimated. We measured the refractive error of early adults aged 18 to 20 years who did not have eye disease. The differences between measurements obtained by subjective refraction and open-field autorefraction for SE, J0, and J45 were $-0.13{\pm}0.53D$ (p=0.17), $+0.33{\pm}0.68D$ (p=0.01), and $+0.13{\pm}0.68D$ (p=0.26), respectively, with only J0 differing significantly. The differences between the measurements of subjective refraction and closed-view autorefraction for SE, J0, and J45 were $-0.30{\pm}0.42D$ (p=0.00), $+0.30{\pm}0.71D$ (p=0.02), and $-0.02{\pm}0.63D$ (p=0.88), respectively, with only SE and J0 differing significantly. The coefficient of accuracy for SE, J0, and J45 components of open-field and closed-view autorefraction were 1.04, 1.33, and 1.34 and 0.83, 1.40, and 1.24, respectively. It is possible to predict the refractive error, which is necessary when deciding on subjective refraction, by measuring the objective refraction of open-field/closed view autorefractors.

• Journal of Korean Ophthalmic Optics Society
• /
• v.18 no.3
• /
• pp.341-346
• /
• 2013

Purpose: The purpose of this study was to evaluate whether a relationship exists between head posture and phoria, and usefulness in examining habitual head posture. Methods: Twenty two subjects (20 males and 2 females, mean age $23.6{\pm}2.7$ years) with abnormal phoria from participants randomized were enrolled in this study. For all subjects, testing included case history, cover test, refraction, phoria and vergence test. Habitual head posture (head posture, head tilt and face turn) was measured by Impression IST, and observed by examiners. Results: The abnormal head posture was revealed in some subjects with abnormal phoria. Spearman' correlation ($\rho$=0.524, p=0.045) showed significant correction between face turn and phoria at distance in 15 subjects with prism prescription. No significant relationship between head posture and phoria was found in subjects with abnormal phoria. The objective measurement and subjective observation of head posture showed insignificant correction but there was a distinct difference. The former was detail and the latter was discriminate. Conclusions: Presence of abnormal head posture was found in phoric subjects. The results indicate the need to observe habitual head posture at all major positions of gaze in phoria.