Browse > Article

The Study of Distance and Near AC/A Ratio by Stimulus  

Jo, Tae-Sik (Department of Optometry, Chodang University)
Kim, In-Suk (Department of Optometry, Chodang University)
Jang, Jung-Un (Department of Optometry, Chodang University)
Publication Information
Journal of Korean Ophthalmic Optics Society / v.16, no.4, 2011 , pp. 417-423 More about this Journal
Abstract
Purpose: This study was to investigate that near gradient AC/A ratio could be used to prescribe a patient with distance exophoria, we compared the difference between distance gradient AC/A ratio and near gradient AC/A ratio. Also, this thesis was to understand the relationship between calculated AC/A ratio and gradient AC/A ratio. Methods: Objective and subjective refractive error were corrected and we used Howell (3 m) chart for distance phoria tests and Howell-Kim (40 cm) chart for near phoria tests. The near gradient AC/A ratio and calculated AC/A ratio were used by Howell-Kim (40 cm) combined with +1.00 D, -1.00 D, +2.00 D and -2.00 D. Results: The average value of distance exophoria was 1.17${\pm}$1.17 $\Delta$, and the average value of near exophoria was 3.71${\pm}$2.80 $\Delta$ (t-test. p<0.001). The correlation of distance phoria with near phoria was little higher (r = 0.59, p < 0.001). Gradient AC/A ratios depending on measuring distance and stimulus were higher (r = 0.11~0.53. P < 0.001), when distance was shorter and stimulus to accommodation was more. Also, stimulus to accommodation by plus lens was higher than stimulus to accommodation by minus lens (paired t-test. p < 0.001). There was negative correlation between calculated AC/A ratio and gradient AC/A ratio. As the calculated AC/A ratio was higher, gradient AC/A ratio was lesser. Near gradient AC/A ratio was slightly higher than distance gradient AC/A ratio. Distance and near gradient AC/A ratio taken through the subjective -1.00 D were 1.30 $\Delta$/D and 1.68 $\Delta$/D(t-test. t=1.67, p < 0.001). Conclusions: There is negative correlation between calculated AC/A ratio and gradient AC/A ratio. Also, there is subtle difference between near gradient AC/A ratio and distance gradient AC/A ratio. Therefore, we need to measure distance gradient AC/A ratio when a practitioner prescribe glasses for a patient with distance exophoria.
Keywords
Stimulus to accommodation; Phoria test; Gradient AC/A; Calculated AC/A; Distance AC/A; Near AC/A;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Fry G. A., "Fuether experiments on the accommodation convergence relationship", Am. J. Optom., 16:125-129(1939).
2 Fry G. A. and Haines H. F., "Tait's analysis of the accommodative-convergence relationship", Am. J. Optom., 17:393-397(1940).   DOI
3 Theodore Grosvenor, "Primary Care Optometry", 4th ed., Butterworth-Heinemann, pp.103(2002).
4 John A. Pratt-Johnson, and Tillson G., "Management of strabismus and amblyopia: A practical guide", lst ed., Thieme medical publishers, New York, pp.258-262(1994).
5 Von Noorden G. K., "The near vision complex: In Von Noorden G. K.: Binocular vision and Ocular motility: Theory and management of strabismus", 5th ed., St. louis, C. V. Mosby, pp.85-99(1996).
6 Julio Prieto-Diaz and Carlos R. Souza-Dias, "Strabismus", 4th ed., Butterworth-Heinemann, pp.63-148(2000).
7 Martens T., and Ogle K., "Observation on accommodative convergence", Am. J. Ophthalmol., 47:455-459(1959).   DOI
8 Wright K. W., "Motor aspect of strabismus. In: Wright K. W., Textbook of ophthalmology", lst ed., Baltimore: Williams & Wilkins, pp.233-253(1997).
9 Ciuffreda K. J., Rosenfield M., and Chen H. W., "The AC/A ratio, age and presbyopia", Ophthalmic Physiological Opt., 17(4):307-315(1997).   DOI   ScienceOn
10 Alpern M., Kincaid W. M., and Lubeck M. J., "Vergence and accommodation. III. Proposed definitions of AC/A ratios", Am. J. Ophthalmol., 48(1, Part2):141-148(1959).   DOI
11 Jaedo Kim, Jack Alexander, and Hellen Swarbrick, "Accommodative response difference between binocular and monocular viewing for difference refractive error types", Invest Opthalmol. Vis. Sci., 42(4):2114(2001).
12 William J. Benjamin, "Borish's Clinical Refraction", W. B. Saunders, pp.758(1998).
13 Elliott D. B., "Clinical procedures in primary eye care", 2nd ed., Butterworth-Heinemann, London, pp.123-125(2003).
14 Hung G. K., Ciuffreda K. J., and Rosenfield M., "Proximal contribution to a linear static model of accommodation and vergence", Ophthalmic Physiological Opt., 16(1):31-41(1996).   DOI   ScienceOn
15 Scheiman M., and Wick B., "Clinical management of binocular vision", 2nd ed., Lippincott Williams & Wilkins, Philadelphia, pp.4-616(2002).
16 Wong E. P., Fricke T. R., and Dinardo C., "Interexaminer repeatability of new, modified prentice card compared with established phoria tests", Optom. vis. Sci., 79(6):370-375(2002).   DOI   ScienceOn
17 김재도, "안경사를 위한 임상검안과 안기능이상 처방", 3판, 신광출판사, pp.176-260(2010).
18 Morgan M., "The clinical aspects of accommodation and convergence", Am. J. Optom., 21:301-313(1944).   DOI
19 한경애, 성아영, "Gradient AC/A비와 Calculated AC/A비의 비교에 의한 근접성 폭주비(PC/A)에 관한 연구", 한국안광학회지, 9(2):223-231(2004).
20 Scheiman M. and Wick B., "Diagnostic testing. In: Clinical management of binocular vision", 2nd ed., Lippincott Williams & Wilkins, pp.3-52(2002).
21 Wick B., "Horizontal deviation. In: diagnosis and management in vision care", Amos. J. ed., Butterworth-Heinemann, Boston, pp.461-510(1987).
22 Sheedy J. E., "Vision problems at video display terminals: a survey of optometrists", J. Am. Optom. Assoc., 63(10):687-692(1992).
23 Grisham J. D., "Visual therapy results for convergence insufficiency: a literature review", Am. J. Optom. Physiol. Opt., 65(6):448-454(1988).   DOI