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http://dx.doi.org/10.14479/jkoos.2014.19.1.17

The Evaluation of Reliability for Exam Distance of Visual Acuity  

Chun, Young-Yun (Dept. of Optometry, Wonkwang Health Science University)
Choi, Hyun-Soo (Vision Optics Lab., Cheongam College)
Park, Seong-Jong (Vision Optics Lab., Cheongam College)
Lee, Seok-Ju (Vision Optics Lab., Cheongam College)
Publication Information
Journal of Korean Ophthalmic Optics Society / v.19, no.1, 2014 , pp. 17-22 More about this Journal
Abstract
Purpose: We aimed to evaluate reliability of eye exam for visual acuity as a function of distance. Methods: There were 39 patients (78 eyes) who had visual acuity 1.0 or more at 5 meters. We measured refractive power of patients at each distances, 5 meters, 4 meters and 3 meters. Automatic chart (LCD-700, Hyeseong Optic. Co., Korea) used for visual acuity, skiascope (Beta 200, Heine, Germany) and auto refractometer (RK-5, Canon, Japan) used as for objective refraction. Accommodation was examined by minus lens addition methods, and Accommodative lag was examined by grid chart for reading distance. Results: Being compared to 3 meter test, Amount of corrected spherical refractive power decreased by $0.10{\pm}0.38$ D, astigmatism decreased by $0.05{\pm}0.10$ D, and axis of astigmatism rotated toward to temporal by $2.64{\pm}18.75$ degrees for right eyes, by $11.43{\pm}48.55$ degrees for left eyes in case of 5 meter test. Changes of corrected refraction and astigmatism were slightly correlated (r=-0.31, r=-0.29). Conclusions: Because corrected refraction power and amount of astigmatism decreased and axis of astigmatism tends to turn the temporal direction according to exam distance, examination distance of visual acuity should improved as to 5 meters.
Keywords
Corrected refractive power; Visual acuity distance; Accommodation; Accommodative lag;
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