• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.59-63
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• 2001

Once refractive error of the eye was fully corrected. Polarization Test was used to investigate binocular vision function. As the results of phoria measurement of Korean adults for 53males and 59 females, orthophoria in 27.68%, esophoria in 12.50%, exophoria in 48.21%, verical phoria in 3.75%, esophoria(+verical phoria) in 2.68%, and exophoria(+vertical phoria) in 5.36%, respectively. Horizontal phoria is below $3{\Delta}$ mostly and verical phoria is below $1{\Delta}$.

• Journal of the Optical Society of Korea
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• v.16 no.4
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• pp.418-424
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• 2012

The purpose of this study was to assess repeatability and reliability of a new phoria test as compared to established phoria tests and to assess the possibility of mobile or online testing using the auto-flashed presentation. Near dissociated phoria was measured using the von Graefe method, the Howell card test, the modified Thorington test, and a new dichromatic card test (Red-Blue Phoria card test; RBP card test) on 109 subjects. The inter-examiner difference and test-retest difference were calculated. With the auto-flashed presentation of the RBP card test, near dissociated phoria was measured and the intraclass correlation coefficient and test-retest repeatability was assessed on 26 subjects. The variation in inter-examiner repeatability was the smallest for the modified Thorington test (+3.1/-2.6). The RBP card test was +3.0/-3.1, the Howell card test was +3.5/-2.7, and the von Graefe test was +6.2/-6.0. The variation in test-retest repeatability was the smallest for the RBP card test (+0.4/-1.4). The modified Thorington test was +1.3/-1.3, the Howell card test was +1.27/-1.45, and the von Graefe test was +1.59/-2.20. The ICC was 0.919 for the auto-flashed presentation of the RBP card test. The RBP card test is considered a highly repeatable method clinically and can be made a useful application for testing in mobile or online.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.2
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• pp.155-160
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• 2010

Purpose: The purpose of this study was to evaluate how phoria variations would vary with head positions, as well as to review the need to differentiate prism placement over either eye in a relation to the imbalance of the extraocular muscle. Methods: This study was carried out with 44 males (88 eyes) and 16 females (32 eyes) aged between 20 and 30. For all subjects, testings were performed using cover test, subjective refraction, phoria and vergence test. To analyze phoria variations comparatively for the head tilt test and the face turn test, phoria deviation were measured using the von Graefe. Results: For the phoria variation related with head tilt and face turn, a significant difference was observed in the group judged to be abnormal on the horizontal phoria of Morgan' norm (p<0.05); especially in patients who needed near prescription of Sheard's criterion, a higher variation was observed (p<0.05). The abnormal group was composed of patients who needed distance prescription of Sheard's criterion and ones who did not need the prescription, all of whom showed phoria variations, but the mean value was less than the near. Conclusions: With regard to the head tilt and face turn related phoria level, the patients who needed near horizontal prism prescription of Sheard's criterion showed a remarkably higher variation. Altogether, it is deemed to check whether extraocular muscles are ill-balanced in both eyes previously to determine the prism power on phoria level to the end that each of prism powers may be accurately determined.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.423-430
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• 2004

This Study on three different methods which are Von Graefe test, Maddox Rod test and Howell card test of measuring far and near lateral phoria investigated. It reviewed that 420 subjects aged from 15 to 35 years old. The result were as follows; 1. Using Von Graefe lateral phoria measurement, they were measured 6% for orthophoria, 62% for exophoria, 32% for esophoria at far distance. 2. Using Von Graefe lateral phoria measurement, they were measured 2% for orthophoria, 74% for exophoria, 24% for esophoria at near distance. 3. Using Maddox Rod lateral phoria measurement, they 59% for exophoria, 37% for esophoria at far distance. 4. Using Maddox Rod lateral phoria measurement, they 67% for exophoria, 30% for esophoria at near distance. 5. Using Howell card lateral phoria measurement, they 60% for exophoria, 32% for esophoria at far distance. 6. Using Howell card lateral phoria measurement, they 69% for exophoria, 27% for esophoria at near distance.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.211-218
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• 2015

Purpose: The aim of this study was to compare the differences among prism settings of the von Graefe technique for phoria measurement. Methods: Thirty eight healthy subjects (mean age $22.35{\pm}2.72years$) were tested with eye examination by interview, cover test, and refraction. Phorias were measured in a random order using four prism settings for the von Graefe method: base-in (BI) and base-up (BU), BI and base-down (BD), BU and BI, and BD and BI over the right and left eye, respectively. Results: Among the four prism settings in measurements of lateral and vertical phoria, there were not significant differences at distance, whereas there were significant at near. The reliability of near lateral phoria (ICC: 0.95) was good, but that of near vertical phoria was less reliable (ICC: 0.83). In comparisons of the paired t-test, the 95% limits of agreement, and mean difference between prism settings, BU had more useful than other prism settings at near phoria. Conclusions: Results from this study suggest that the von Graefe test with BU or BU including other setting prisms have useful methods, especially for near phoria measurements.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.331-337
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• 2014

Purpose: This is a comparative experimental study on the amount of phoria by the removal time of binocular fusion. In this study, three tests were used for phoria test like Howell test, Thorington test and developed 3D polarizing test. Methods: In this study, it was considered the removal time of binocular fusion for measuring phoria. The three methods were used for measuring quantity of phoria: Howell test, Thorington test and developed 3D Polarizing test. The measurements progressed quickly to avoid eye-strain. So we designed the test charts for marking 3D display modules and the apparatus inserted lenses, like Maddox lens and prism, which are compatible with three phoria tests. The phoria at the moment separation was measured when the binocular fusion was broken through the apparatus and the that at the stable separation was measured when activity of the separated two images like indicated box and figure on horizontal axis stopped. Results: There were statistically significant difference between quantity of phoria at moment separation and that at stable separation. Amount of phoria at moment separation was relatively larger than amount of that at stable separation. In result in exophoria, the quantity of phoria at moment separation was higher than that at stable separation, and in phoria measured by developed 3D polarizing test, it shows the similar results at two condition. Conclusions: For exophoria, the amount of phoria at moment separation of binocular fusion was relatively larger than that at stable separation. The amount of difference between phoria values at moment separation and that at stable separation was alike among three phoria tests. Usually in working, there is no distinction between moment separation and stable separation. But there were definitely the difference between two ways to separate binocular fusion. Therefore, it is need for writing on prescription test name for measuring phoria and condition of separation of binocular fusion.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.79-87
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• 2008

Purpose: This study measured Y-intercept that means a fixation disparity, X-intercept that means a associated phoria and slope of a fixation disparity curve (FDC), which are variables of dissociated phoria and the FDC. We searched for the result value and examined the direction, distribution pattern and a variable that give an most affect on dissociated phoria and the FDC at distance and near. Also this study examined that there were statistically significant differences between distance and near, comparing the result value. Methods: We measured the dissociated phoria and the fixation disparity for 51 subjects at distance and near in June, 2007. All subjects ranged from 20 to 25 years of age (average 21.72${\pm}$1.88 years old) and had no eye disease. At distance the dissociated phoria measured with the distance MIM card (muscle imbalance measure card, Bernell co., USA), and the fixation disparity measured with the modified Mallett Far Unit (Bernell co., USA). At near the dissociated phoria measured with the near MIM card (muscle imbalance measure card, Bernell co., USA), and the fixation disparity measured with the Wesson fixation disparity card (American Optical co., USA). Results: The percentage distribution of types of fixation disparity curves was that at distance prevalence of Type I (74.6%) was the highest, followed by Type IV (17.6%) and Type II (3.9%), Type III (3.9%) and that at near prevalence of Type I (53.0%) was the highest, followed by Type III (29.4%), Type IV (13.7%) and Type II (3.9%). 2. There were significantly correlation in dissociated phoria, fixation disparity (Y-intercept) and associated phoria (X-intercept). 3. The fixation disparity at distance was most affected by associated phoria (X-intercept) (p=0.000). The distance dissociated phoria was most affected by fixation disparity (Y-intercept) (p=0.342), but the influence was weak. 4. The fixation disparity at near was most affected by associated phoria (X-intercept) (p=0.000). The near also dissociated phoria was most affected by associated phoria (X-intercept) (p=0.009). The result that compared the each variables with the same variables at distance and near had statistically significant on paired t-test for among dissociated phoria (t=7.529, p=0.000), X-intercept (t=5.860, p=0.000), the Y-intercept (t=4.640, p=0.000) but slope of the FDC did not differ significant (t=1.336 p=0.188). Conclusions: Relationship of fixation disparity and Heterophoria had close correlation at distance and near.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.251-255
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• 2004

Our research is about the measurement of the distance & near horizontal phoria by the Von Graefe test. The inspection was processed about normal 60 subjects(120eyes) aged from 20 to 30) years old by the subjective method of refraction. Among 120 eyes, the myopia is 64eyes(53%) and the emmetropia is 56eyes(47%). In the measurement of the distance horizontal phoria, we could know that the exophoria is 40%(24 subjects), the esophoria is 40%(24 subjects), and the orthophoria is 20%(12 subjects). In case of the near horizontal phoria, we could know that the exophoria is 65%(39 subjects), the esophoria is 23.3%(14 subjects), and the orthophoria is 11.7%(7 subjects).

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.2
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• pp.13-18
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• 2003

We did the comparison research about three different methods of measuring horizontal phoria and vertical phoria which are Von Graefe test, Maddox Rod test and polarizing lens test. The inspection was don with the subjective method of refraction about normal 63 subjects aged from 20 to 28 years old. The analysis of date resulted in as follows : 1. Using Von Graefe Horizontal phoria Measurement, they were measured 5% for orthpharia, 51% for exophoria and 44% for esophoria. 2. Using Von Graefe vertical phoria Measurement, they were measured 68% for orthphoria, 20% for left hypophoria against the right and 12% for left hyperphoria against the right. 3. Using Maddox Rod Horizontal phoria Measurement, they were measured 7% for orthphoria, 49% for exophoria and 44% for esophoria. 4. Using Maddox Rod vertical phoria Measurement, they were measured 70% for orthphoria, 19% for left hypophoria against the right and 11% for left hyperphoria against the right. 5. Using Polarizing Horizontal phoria Measurement, they were measured 10% for orthphoria, 49% for exophoria and 41% for esophoria. 6. Using Polarizing vertical phoria Measurement, they were measured 92% for orthpharia, 5% for left hypophoria against the right and 3% for left hyperphoria against the right.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.3
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• pp.269-274
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• 2010

Purpose: The repeatability of a new Red-Blue phoria chart test (Red-Blue phoria chart; RBP) was appreciated. Methods: Distance (5 m) and near (40 cm) heterophoria was measured in 38 visually normal subjects. Phoria tests using RBP, Howell phoria card (HP), and MIM card (MIM) were done and the repeatability of each phoria test was compared with one another. Results: The mean of horizontal deviations was that RBP was $-0.602{\pm}0.727{\Delta}$, HP was $-0.865{\pm}1.051{\Delta}$, and MIM was $-1.501{\pm}1.346{\Delta}$, at distance, and that RBP was $-2.566{\pm}2.352{\Delta}$, HP was $-2.804{\pm}2.411{\Delta}$, MIM was $-3.838{\pm}2.603{\Delta}$, at near. The repeatability was RBP>MIM>HP in distance tests and MIM>RBP>HP in near tests. Conclusions:RBP test is identified as a reliable phoria test having high repeatability.