• Journal of The Korean Ophthalmological Society
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• v.60 no.5
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• pp.470-473
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• 2019

Purpose: To investigate the relationship between dominant eye and refractive error in patients with myopic anisometropia. Methods: This study population consisted of myopes less than 15 years old who were followed up for anisometropia defined as interocular difference of spherical equivalent (SE) ≥1.0 diopter (D). All patients underwent the hole-in-the-card test at far and near to determine ocular dominance. The data were analyzed for statistical significance using Fisher's exact test. Results: A total of 102 eyes in 51 patients were analyzed. The mean age of the patients was 10.4 ± 1.4 years and 54.9% were male. The mean SE was -2.97 ± 1.95 D in the right eye and -3.02 ± 1.92 D in the left eye. The right eye was the dominant eye in 43.1% and 37.3% at distance and near, respectively. The agreement of dominancy between distant and near was 82.4%. The near dominant eyes showed statistically significant accordance with more myopic eyes (p = 0.009). On the other hand, there was no statistically significant relationship between more myopic eyes and distant dominant eyes (p = 0.09). Conclusions: The near dominant eye was more myopic eye in patients with myopic anisometropia. This was considered to be related with the lag of accommodation in dominant eye with near distance.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1538-1543
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• 2016

Strabismus is a non-aligned state;the visual axis of each eye is not directed toward the same direction at the same time. Clinically, the degrees of strabismus are measured by prism cover test, corneal reflex test (Hirschberg test), prism reflex test (Krimsky prism test), But corneal reflex test and prism reflex test is a possibility that errors occur. we suggest a computer-aided diagnosis for strabismus. We made a mobile application to measure angles of strabismus. For 34 patients, we tested our application. The result of comparing between two methods, It showed a difference 7 Prism Diopter(PD). Our application gives strabismus angles just using a camera and a smart device. Therefore, it can reduce the cost and make the diagnosis of strabismus accurate.

• Journal of Korean Medical Science
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• v.33 no.44
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• pp.275.1-275.15
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• 2018

Background: We compared the efficacy between trifocal and bifocal diffractive intraocular lens (IOL) implantation. Methods: Through PubMed, MEDLINE, EMBASE, and CENTRAL, we searched potentially relevant articles published from 1990 to 2018. Defocus curves, visual acuities (VAs) were measured as primary outcomes. Spectacle dependence, postoperative refraction, contrast sensitivity (CS), glare, and higher-order aberrations (HOAs) were measured as secondary outcomes. Effects were pooled using random-effects method. Results: We included 11 clinical trials, with a total of 787 eyes (395 subjects). The trifocal IOL group showed better binocular distance VA corrected with defocus levels of -0.5, -1.0, -1.5, and -2.5 diopter than the bifocal IOL group (All $P{\leq}0.004$). The trifocal IOL group showed better monocular uncorrected distance and intermediate VAs (mean difference [MD], -0.04 logarithm of the minimum angle of resolution [logMAR]; 95% confidence interval [CI], -0.07, -0.01; P = 0.006 and MD, -0.07 logMAR; 95% CI, -0.13, -0.01; P = 0.03, respectively). Postoperative refraction, glare, CS, and HOAs were not significantly different from each other. Conclusion: The overall findings indicate that trifocal diffractive IOL implantation is better than the bifocal diffractive IOL in intermediate VA, and provides similar or better in distance and near VAs without any major deterioration in the visual quality.

• Journal of the Optical Society of Korea
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• v.17 no.4
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• pp.328-335
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• 2013

Due to the rapid advancement of auto-refractor technology, most optometry shops provide refraction services. Despite their speed and convenience, the measurement values provided by auto-refractors include a significant degree of error due to psychological and physical factors. Therefore, there is a need for repetitive testing to obtain a smaller mean error value. However, even repetitive testing itself might not be sufficient to ensure accurate measurements. Therefore, research on a method of measurement that can complement auto-refractor measurements and provide confirmation of refraction results needs to be conducted. The customized optometry model described herein can satisfy the above requirements. With existing technologies, using human eye measurement devices to obtain relevant individual optical feature parameters is no longer difficult, and these parameters allow us to construct an optometry model for individual eyeballs. They also allow us to compute visual images produced from the optometry model using the CODE V macro programming language before recognizing the diffraction effects visual images with the neural network algorithm to obtain the accurate refractive diopter. This study attempts to combine the optometry model with the back-propagation neural network and achieve a double check recognition effect by complementing the auto-refractor. Results show that the accuracy achieved was above 98% and that this application could significantly enhance the service quality of refraction.

• Journal of Korean Clinical Health Science
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• v.1 no.1
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• pp.1-7
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• 2013

Purpose. To analysis the prevalence of the myopia and corneal astigmatism in Korea women university students. Methods. From August 2011 to December 2012, one hundreds subjects were performed in refraction test using the Auto-Keratometry. Results. The mean age of the 100 subjects (200 eyes) was $21.23{\pm}2.34$. The mean spherical refractive power was -$1.78{\pm}1.65$(OD) and -$1.83{\pm}1.67$(OS) Diopter. The mean astigmatism power was $1.22{\pm}0.96$ (OD) and $1.27{\pm}0.91$ (OS). The mean corneal astigmatism was $1.44{\pm}0.81$(OD) and $1.55{\pm}0.93$(OS). Corneal astigmatism was between 0.25 D and 1.25 D in 67.7% of eyes, 1.25 D or higher in 27.5% eyes, and less than 0.25 D in 4.8% of eyes. Astigmatism was with the rule in 65%, against the rule in 31.5%, and oblique in 3.5%. There was a statistical significance between right eye and left eye in the spherical equivalent power(p=0.002). Also there was a statistical significance between spherical power and refractive astigmatism in OD(p=0.006) and OS(0.003) and a statistical significance between corneal astigmatism and refractive astigmatism in OS(p=0.0003). However, there was not a statistical significance between spherical power and corneal astigmatism in OD(p=0.08) and OS(0.1) and a statistical significance between corneal astigmatism and refractive astigmatism in OS(p=0.48). Conclusions. In this study, these results suggested that the analysis of the refractive myopia and corneal astigmatism can provide the visual correct and useful diagnosis information for the eyewear dispensing, contact lens fitting and corneal refraction surgery.

• The Journal of Pediatrics of Korean Medicine
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• v.29 no.4
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• pp.12-22
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• 2015

Objectives Myopia has a higher prevalence rate in eastern countries, which also have a higher rate of educational fever compared to western countries. Considering this, social costs paid for myopia will increase rapidly in Korea. Although the development of myopia treatment is necessary, there has been a lack of relevant studies. Thus, this study aims to produce data to prevent unnecessary treatments and medical expenses. Methods The objective is to evaluate the effect of periocular acupressure exerted by a medical massager for myopia. This is an open-label, prospective, single-arm, and pre and post superiority study. The subjects are 7~12-year-old myopia patients with under 5 D (diopter) of spherical equivalent. A total of 56 subjects were enrolled. The selected subjects will wear the massager for 15 minutes twice a day for 24 weeks. The primary endpoint is the refraction change. The secondary endpoint is the axial length change. Statistical analysis was performed at a significant level of 0.05, using a two-tailed test. The criterion for significantly improved refraction was $-0.17{\pm}0.50$ D/6 months and that of axial length change was 0.126 mm. Results and Conclusions This study did not include a control group because children represent a vulnerable group. This objective study will bring some impact on Korean medical myopia treatment. A long-term confirmatory clinical study may be necessary in future.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.1
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• pp.67-71
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• 2010

Purpose: The effect of two different levels of illumination and the effect of three letter chart types on subjective refraction findings were investigated. Methods: This study involved thirty Malay university students aged between 19 to 23 years old (7 males, 23 females), with their spherical refractive error ranged between plano to -7.75D astigmatism ranged from plano to -1.75D, anisometropia less than 1D and with no history of ocular injury and pathology. Monocular subjective refraction was measured under two levels of illumination (with and without room light) and with three different letter charts (Snellen letter chart, wall mounted letter chart and projected letter chart). Subjective refraction finding was calculated in spherical equivalent in unit diopter (D). Results: There was no significant effect in the subjective refraction findings with Snellen letter chart (t-test=0.15, p-value=0.88), projected letter chart (t-test=-0.19, p-value=0.85) as well as wall mounted letter chart (t-test=0.12, p-value=0.94). One Way ANOVA also revealed when the subjective refractive measures were compared under two different level of room illumination (with and without room light), no significant effect of letter chart types on subjective refraction readings with room light ($F_{2.185}$=0.11, p-value=0.89) and without room light ($F_{2.185}$=0.02, p-value=0.98). Conclusions: Subjective refraction findings were not affected whether the room light was on or off. They were also not affected by the types of letter chart used.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.139-146
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• 2000

Once refractive error of the eye was fully corrected, Maddox rod was used to investigate binocular vision function. When the deviations of subjects' eyes were measured, orthophoria. without any horizontal deviations, was found in 10%, esophoria in 55% and exophoria in 34% of the patients. Esodeviation of the eye was found to be greater than exo-deviation by 11%. This is also refracted in deviations found to be greater than $4{\Delta}$ diopter magnitude where esophoria was 23% and exophoria was 9%. Thus for the patients to achieve comfortable binocular vision function, binocular vision anomalies need to be considered in spectacle prescription. In examining ocular anomalies of corrected refractive error, the deviation of the eye differed from under corrected refractive power to over corrected refractive power. There was a decrease in exophoria and an increase in esophoria, with over correction. This was thought to be due to accommodation. Furthermore, calculated AC/A ratio was found to vary from 1.25 to 6.61 and its relationship to refractive error could not be determined.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.121-126
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• 2008

Purpose: To study the minimum diopter of spherical lens with normal binocular function in induced anisometropia by over-correction or under-correction in single eye. Methods: Stereoacuity of subjects without ophthalmic disease history in their twenties was measured by using Titmus-fly stereotest at 40 cm after overcorrection or under-correction in non-dominant eye or dominant eye, respectively. Results: In induced anisometropia, the stereoacuity decreased with increase of the power of added spherical lens in either nondominant eye or dominant eye. And the first reduction of stereoacuity was more prominent with the addition of (+) spherical lens than (-) spherical lens. In addition, there was more strikingly decrement of stereoacuity with addition of spherical lens to dominant eye than non-dominant eye. Conclusions: In induced anisometropia, the most outstanding reduction of stereoacuity was obtained with increment of the power of added (+) spherical lens in case of non-dominant eye with full correction and dominant eye with addition of spherical lens.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.535-540
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• 2012

This study is to research the differences of tear film for young people in of a day in a restricted indoor space. The subjects are 58 eyes volunteers for twice preliminary inspection and tear test of a day. 58 healthy individuals with no eye disease, no body disease, orthophoria, corrective visual acuity more than 0.8, binocular spherical equivalence difference over 0.50 diopter, the flattest corneal curvature in horizontal meridian and the steepest corneal curvature in vertical meridian were tested. The uncorrective visual acuity, refractive error, corneal curvature, schirmer test and tear break up test were performed in the morning and afternoon. Schirmer test were $16.0{\pm}7.0mm$ in the morning and $14.1{\pm}7.1mm$ in the afternoon. TBUT were $11.3{\pm}0.6$ sec in the morning and $12.1{\pm}0.9$ sec in the afternoon. They have no significant differences.