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Comparison between Response AC/A and CA/C Ratio according to Additional Spherical Powers and Prism Powers

가입렌즈 도수와 프리즘 굴절력 변화에 따른 반응 AC/A비와 CA/C비 비교

  • Received : 2015.07.30
  • Accepted : 2015.09.08
  • Published : 2015.09.30

Abstract

Purpose : This study was to examine a correlation of response AC/A ratio by additional spherical powers with PD(Pupilary distance) and relative accommodation, and was to investigate correlation of CA/C ratio by prism powers. The mean differences between a reciprocal response AC/A ratio and a CA/C ratio were compared, and were suggested to be used as data in the refractive power and prism prescriptions in the clinical. Methods: The open field autorefractometer (Nvision-K 5001, Shin nippon) and Howell target at 40 cm fixation distance to 62 persons with average $22.62{\pm}2.84$ ages were used to measure the response AC/A ratio according to additional Spherical powers. The CA/C ratios were measured using the DOG card at 40cm according to prism powers. Results: When the response accommodation according to Additional Spherical power changes and the response accommodation according to prism power changes were compared, it was larger than the response accommodation according prism power change. These were significant differences statistically. The correlation of response AC/A ratio and PD is showed as r = -0.158, the CA / C ratio is shown as r = 0.093. The correlation of response AC/A ratio and relative accommodation showed as r = -0.253, the CA/C ratio showed as r = 0.566 that is predictable correlation. The correlation of response AC/A ratio and CA/C ratio showed as r = -0.355 that is low minus correlation (p = 0.000). The difference between a reciprocal response AC/A ratio and a CA/C ratio showed $0.12{\pm}0.06D/{\Delta}$ with a significant difference statistically (p=0.000). Conclusions: The correlation of relative accommodation and CA/C ratio showed that depend on the individual, The more a relative accommodation is, the higher a response accommodation of convergence by convergence stimulus is. The reciprocal response AC/A and CA/C ratio showed significant differences statistically. This can have higher CA/C ratio in patients with low AC/A ratio in clinical as an independent variable. Thus when the abnormal binocular vision was prescribed in the clinical, it is necessary to consider the accommodative response even if the AC/A ratio is a normal range.

Keywords

Accommodative response;Convergence accommodation;Relative accommodation;Response AC/A ratio;CA/C ratio

References

  1. Kim DN. Binocular Vision. 2nd Ed. Seoul: Shinkwang, 2015:176-177.
  2. Martens TG, Ogle KN. Observations on accommodative convergence; especially its nonlinear relationships. Am J Opthalmol.1959;47:455-462. https://doi.org/10.1016/S0002-9394(14)78051-1
  3. Grosvenor TP. Primary care optometry: anomalies of refraction and binocular vision, 3rd Ed. Boston: Butterwoth-Heinmann, 1996:575.
  4. Rainey BB, Goss DA, Kidwell M, Feng B. Reliability of th response AC/A ratio determined using nearpoint autorefraction and simultaneous heterophoria measurement. Clin Exp Optom. 1998;81(5):185-192. https://doi.org/10.1111/j.1444-0938.1998.tb06733.x
  5. Lee SH, Yu DS, Son JS, Kwak HW. Comparison between stimulus and response AC/A ratios for each phoria additional spherical power. J Korean Opthalmic Opt Soc. 2014;19(3):345-351. https://doi.org/10.14479/jkoos.2014.19.3.345
  6. Goss AD, Vatnasdal P, Babinsky E, Candy RT. Comparion of three methods of measuring CA/C rations. Optom Vis Perf. 2015;3(1):14-25.
  7. Rainey BB. The effect of prism adaptation on the response AC/A ratio. Ophthalmic Physiol Opt. 2000;20(3):199-206. https://doi.org/10.1016/S0275-5408(99)00068-X
  8. North R, Henson DB. Adaptation to prism-induced heterophoria. Am J Optom Physiol Opt. 1980;57(3):129-137. https://doi.org/10.1097/00006324-198003000-00001
  9. Lee MH, Yu DS. CA/C ratio of adults in their early twenties with normal binocular vision. J Korean Opthalmic Opt Soc. 2012;17(2):153-158.
  10. Kent PR. Convergence accommodation. Am J Optom Arch Am Acad Optom. 1958;35(8):393-406. https://doi.org/10.1097/00006324-195808000-00001
  11. Southall JPC. Helmholtz's treatise on physiological optics, 3rd Ed. Canada: General, 1924;382-415.
  12. Benjamin WJ. Borish's clinical refraction, 2nd Ed. St. Louis: Butterworth-Heinemann, 2006;908-909.
  13. Rosenfield M, Gilmartin B. Assessment of the CA/C ratio in a myopic population. Am J Optom Physiol Opt. 1988; 65(3):168-173. https://doi.org/10.1097/00006324-198803000-00005
  14. Nonaka F, Hasebe S, Ohtsuki H. Convergence accommodation to convergence (CA/C) ratio in patients with intermittent exotropia and decompensated exophoria. Jpn J Opthalmol. 2004;48(3):300-305. https://doi.org/10.1007/s10384-004-0060-4
  15. Bruce AS, Atchison DA, Bhoola H. Accommodationconvergence relationships and age. Invest Ophthalmol Vis Sci. 1995;36(2):406-413.
  16. Rosenfield M, Ciuffreda KJ, Chen HW. Effect of age on the interaction between the AC/A and CA/C ratios. Ophthalmic Physiol Opt. 1995;15(5):451-455. https://doi.org/10.1016/0275-5408(95)00061-H
  17. Semmlow JL, Heerema D. The role of accommodative convergence at the limits of fusional vergence. Invest Ophthalmol Vis Sci. 1979;18(9):970-976.
  18. Semmlow JL. Heerema D. The synkinetic interaction of convergence accommodation and accommodative convergence. Vision Res. 1979;19(11):1237-1242. https://doi.org/10.1016/0042-6989(79)90189-5

Cited by

  1. Comparison of CA/C Ratio with Different Measuring Methods vol.22, pp.2, 2017, https://doi.org/10.14479/jkoos.2017.22.2.151

Acknowledgement

Supported by : 경운대학교