• Journal of Korean Ophthalmic Optics Society
• /
• v.18 no.3
• /
• pp.313-320
• /
• 2013

Purpose: This study compared the quantity of phoria for distance by new method with that by existing methods. Methods: For this study, it was selected to two existing phoria measurements, von Graefe and Maddox rod. And new method named "3D polarizing phoria measurement" was designed to measure the quantity of phoria using polarizing glasses and 3D display. Unlike existing measurement using polarized lens, newly considered method measured the quantity of phoria in condition removed perfect binocular fusion using field stop on apparatus and polarized lens. For using new method for distance, it was developed a phoria test chart. It supports three kinds of phoria measurements. Subjects were 12 (male 6, female 6). They had three phoria tests (1 sets) including new method. It was considered the effect of experimental order, so we tested all cases about experimental order. The number of cases was 6 sets, and the sample size in this experiment was 72 sets. For removing binocular fusion, lighting of the laboratory that was below 10 lx and the background color of phoria test chart was dark, RGB=(20, 20, 20). Results: Subjects were sorted into three groups. Samples with exophoria and orthophoria were 30 sets each, and those with esophoria were 12 sets. The quantity of phoria measured three tests differ from each other like "newmethod < von Graefe < Maddox rod", and there were statistically significant difference each other. Conclusions: This study has great significance in the sense that new method was the measurement with naturally removing binocular fusion without dizziness during the tests.

• Proceedings of the KAIS Fall Conference
• /
• 2010.05b
• /
• pp.894-897
• /
• 2010

적청 색필터와 새로운 시표를 이용한 교대가림법(Twinkle R/B법)이 임상적으로 새로운 사위검사법으로 사용될 수 있는지 그 가능성을 평가하였다. 대학생 109명(남 73명, 여 36명)을 대상으로 Twinkle R/B법, Modified Thorington법, Howell법, 그리고 Von Graefe법으로 40cm 거리에서 사위검사를 실시하였다. 사위검사는 검사자별로 반복 측정을 실시하여 검사방법에 따른 신뢰도를 평가하였다. 실험 결과, 검사자의 반복측정에 따른 신뢰도는 Twinkle R/B법이 가장 높았다. 결과적으로 Twinkle R/B법은 신뢰도가 높은 사위검사법으로서 임상에서 충분히 사용 가능한 것으로 나타났다.

• Journal of Korean Ophthalmic Optics Society
• /
• v.14 no.2
• /
• pp.41-46
• /
• 2009

Purpose: Stereopsis is one of primary characteristics for assessment of binocular function. The purpose of this study was to determine the possible relationship between the degree of exophoria and stereoacuity at near. Methods: 110 exophores (male n=71, female n=39, mean $age{\pm}SD=11.30{\pm}1.47$ years) without amblyopia, strabismus, and ocular and systemic pathology were studied. Subjects were also excluded if they had visual acuity poorer than 0.8 in either eye or vertical phoria greater than 1 prism diopter. Clinical tests were performed for near phorias by von Graefe technique using a Digital Refractor (CDR-3100, Huvitz, Korea) with chart (Predio CDC-4000, Huvitz, Korea), and for stereoacuity using the Titmus fly. Results: A one-way analysis of variance revealed that mean values of the stereoacuity classified according to the degrees of the exophoria were not significantly different (p>0.05). Conclusions: Based on the result of this study, it was found that there was no relationship between the degree of exophoria and stereoacuity.

• Journal of Korean Ophthalmic Optics Society
• /
• v.16 no.2
• /
• pp.179-186
• /
• 2011

Purpose: This study aimed to compare and assess changes of visual functions in viewing an anaglyph 3D image. Methods: Visual functions were examined before and after viewing a 2D image and an anaglyph 3D image with red-green glasses on seventy college students (mean age = 22.29${\pm}$2.19 years). Visual function tests were carried out for von Graefe phoria test, accommodative amplitude test by (-) lens addition, negative relative accommodation (NRA) and positive relative accommodation (PRA) test, negative relative convergence (NRC) and positive relative convergence (PRC) test, accommodative facility, and vergence facility test. Results: Assessment of the visual functions indicated that near exophoria and accommodative amplitude were reduced after viewing a 3D image, and although there were small changes in relation to these findings, NRC and PRC showed tendencies to increase and decrease at near, respectively. There were no significant changes with NRA and PRA, and accommodative and vergence facility were shown to have improved. Conclusions: Changes of visual functions were more in the 3D image than the 2D image, especially at near than distance. Particularly, the improvement of accommodative and vergence facility could be related to an effect of subsequent accommodation and vergence shift to have stereopsis in the 3D image. These results indicate that an anaglyph 3D image may, to some extent, be the effect of vision training such as anaglyphs.

• Journal of Digital Convergence
• /
• v.11 no.11
• /
• pp.661-666
• /
• 2013

The aim of this study was to evaluate the property of heterophoria and fusional reserve in Adults in Jeon-buk Area. We examined the corrected visual acuity, corrected refractive error, heterophoria and fusional reserve of 116 healthy myopes aged from 20 to 44 old who had no strabismus no ocular and phyisical diseases. Using Von Graefe test of horizontal heterophoria Measurement, we measured orthophoria(26.7%), exophoria(52.5%) and esophoria(20.7%) for at near distance. The subjects who had exophoria of 0-6${\Delta}$ in the range of normal state was 38.8%, while the subjects who had exophoria in the range of abnormal state was 61.2%. Reducing fusional reserve was associated with increasing phoria. We found a relationship between asthenopia and fusional reserve of heterophoria and considered that fusional reserve must be examined when we preserve for a patient with heterophoria. Furthermore, Gradient method AC/A ratio was found 4.03 and its relationship to refractive error could not be determined.

• Journal of Korean Ophthalmic Optics Society
• /
• v.14 no.3
• /
• pp.37-42
• /
• 2009

Purpose: There is uncertainty if the vergence facility would provide clinically significant supplementary information to the fusional vergence measurements. The purpose of this study was to determine the relationship between vergence facility and fusional vergence in a group of symptomatic subjects. Methods: A total of 114 symptomatic subjects aged 9 to 13 years, who passed the vision screening test, participated in this study. Vergence facility was measured with 8$\Delta$ BI/8$\Delta$ BO flipper lenses and a suppression control target, the 20/30 letter line on Vectogram 9 (Bernell, USA). Near fusional vergence was measured with a single 20/30 vertical line target by Von Graefe technique. In order to avoid excessive convergence stimulation, negative fusional vergence (NFV) range (blur, break and recovery) was measured followed by positive fusional vergence (PFV) ranges (blur, break and recovery). Results: Pearson correlations were calculated and showed no correlations between vergence facility and any of fusional vergence measurements (p>0.05). Also, there were no significant differences of vergence facility measurements on the compensating vergence that passed or failed Sheard and Morgan's criterion for comfortable vision (p>0.05). Conclusions: There was no correlation between vergence facility and fusional vergence among symptomatic subjects. Hence, both vergence facility and fusional vergence should be assessed for those with binocular dysfunction in order to make an accurate diagnosis and management plan.

• Journal of Korean Ophthalmic Optics Society
• /
• v.9 no.2
• /
• pp.361-370
• /
• 2004

The purpose of this study was to evaluate the outcome and Factors that influence the quantity of Phoria in the low correction and perfect correction. Also the coincidence with the opticenter and the pupillary distance was a principal factor that influence the quantity of Phoria. Thereupon, this study is attributed to promote the perfect Phoria test. The subjects for this study were 120 persons(240 eye) in myopic refractive errors. ISP/WIN program was used for the data analysis. The collected data was analyzed by descriptive statistics and Spearman's correlation coefficient. The results of this study were as follows: 1. The prism pattern was difference between low correction and perfect correction in the Phoria test. The proportion of orthophoria was changed from 10.0% to 12.5%, exophoria was changed from 67.5% to 62.5%, and esophoria was changed from 22.0% to 32.5%, respectively. 2. The average of optical center distance and pupillary distance were 31.70mm and 31.49 mm, respectively. 3. Among the 120 myopic glasses wearers, the distance between optical centers was coincided with the pupillary distance in 37.5%, and discrepant in 62.5%. 4. For the patients who were coincided with the pupillary distance, the proportion of exophoria decreased 53.33%, esophoria increased 20.0%. 5. For the changing of the quantity of Phoria in the low correction, the degree of exophoria decreased 1.11 prism diopters in the perfect correction, esophoria increased 0.39 prism diopters.

• Journal of Korean Ophthalmic Optics Society
• /
• v.15 no.2
• /
• pp.155-160
• /
• 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
• /
• v.10 no.2
• /
• pp.103-110
• /
• 2005

Binocular vision had a short history in Korea. As there were many near works in these days, the needs about comparative study have been increased. There was related to both refractive error and binocular anomalies, but it is difficult to applying for binocular vision expected findings in itself due to the fact that Korean differ from foreigner. Objects were 100 adults in 18-36 years old ages, The test was Von Gaefe method and used aparatus was phoropter(Shinnippon VT10)and visual chart(Shinnippon CT30). According to interview results was that symptom in near works were headaches 28.0%, blinking 27.3%, red eye 25.1%, eyepain 15.6%, watering 15.3%, itch 12.2%, photophobia 8.5% and eye strain 7.4%. A people who have above ${\pm}0.50$ D refractive error in total objectives (100-male 45/female 55) were classified into ametropia. There was a results such as emmetropia (12.0%), ametropia(88.0%), exophoria(32.0%), esophoria(12.0%). Far negative relative convergence were that in case of high 43.0%, in case of low 7.0%. Far positive relative convergence were that in case of high 15.0%, in case of low 38.0%. Near phoria was exophoria(32.0%), esophoria(12.0%). Near negative relative convergence were that in case of high 23.0%, in case of low 38.0%. Far positive relative convergence were that in case of high 29.0%, in case of low 23.0%. Near negative relative accommodation were that in case of high 10.0%, in case of low 14,0%, Far positive relative convergence were that in case of high 69.0%, in case of low 12.0%. Results were different from expected findings, and especially positive relative accommodation was very high, However, We suggest that the expected findings in Korea for several subjects must study in binocular function.

• Journal of Korean Ophthalmic Optics Society
• /
• v.21 no.3
• /
• pp.235-242
• /
• 2016

Purpose: This study was to investigate whether the application of different diagnostic criteria affected the frequency of convergence insufficiency (CI). Methods: Eighty one subjects with mean age of 22.54 years (20 to 27 years) were evaluated. Binocularity tests after refraction were performed as the following tests: near point of convergence (NPC) with an accommodative target, phoria using von Graefe method, positive fusional vergence (PFV) with a phoropter. Subjects with CI were diagnosed when exophoria (exo) was greater at near than at distance ($exo{\geq}4{\Delta}$, or >$6{\Delta}$), fusional vergence was $PFV{\leq}11{\Delta}$ for blur, $PFV{\leq}15{\Delta}$ for break, Sheard's or Percival's criterion, and NPC was $NPC{\geq}6cm$, ${\geq}7.5cm$ or >10 cm. Results: Frequency of CI with one diagnostic criterion was ranged from 6.2% to 77.8%, and was overestimated or underestimated according to criteria. It was reduced to the range of 6.2% to 43.2% with diagnostic criteria more than two, especially to the range of 24.7% to 28.4% with lower variability in diagnostic criteria including phoria and Sheard's criterion. There were high relationship between total score of signs and phoria score (r = 0.772, p<0.001), and measured phoria and Sheard's criterion (r = -0.654, p<0.001), but NPC had a high variability and a weak or no significant relationship with other diagnostic criteria. Results suggested $exo{\geq}4{\Delta}$, Sheard's criterion and $NPC{\geq}7.5cm$ for diagnostic criteria of signs and sequence for CI. Conclusions: Frequency of CI is likely to be over- and underestimated with diagnostic criteria. Cutoff values and procedures for phoria, Sheard's criterion and NPC as clinical signs should be suggested definitely in diagnosis associated with CI.