The purpose of this study was to determine the relationship between the spherical equivalent visual acuity (VA) and uncorrected astigmatism. On 108 emmetropic eyes, the spherical equivalent VA was measured for cross cylindrical lens (CC lens)-induced astigmatic eyes and the VA-astigmatism relation determined. On 158 astigmatic eyes, the spherical equivalent VA and corrected astigmatism were measured and the measured values were compared with the calculated values from the VA-astigmatism relation by correlation coefficient analysis. Subsequent to that, the relationship between spherical equivalent VA and uncorrected astigmatism was made. The relationship was fitted for an exponential equation. Correlation coefficient between calculated values by equation and measured values for astigmatic eyes was 0.991 (p<0.01). The relationship between the spherical equivalent VA and the uncorrected astigmatism was decided as follows (spherical equivalent VA / uncorrected astigmatism): 1.0 / 0.25 D, 0.9 / 0.50 D, 0.8 / 0.75 D, 0.7 / 1.00 D, 0.6 / 1.25 D, 0.5 / 1.50 D, 0.4 / 2.00 D, 0.3 / 2.50 D, 0.2 / 3.00 D, 0.1 / 4.00 D, and 0.05 / 4.75 D. In conclusion, the relationship table devised from this study is a useful reference for predicting uncorrected astigmatism by measurement of decimal VA in spherical equivalent.
© 2013 Optical Society of Korea
(170.1610) Medical optics and biotechnology : Clinical applications
(330.1070) Vision, color, and visual optics : Vision - acuity
(330.7333) Vision, color, and visual optics : Visual optics, refractive anomalies
Original Manuscript: December 21, 2012
Revised Manuscript: February 4, 2013
Manuscript Accepted: February 21, 2013
Published: April 25, 2013
Byeong-Yeon Moon, Sang-Yoeb Kim, and Hyun Gug Cho, "Predicting of Uncorrected Astigmatism from Decimal Visual Acuity in Spherical Equivalent," J. Opt. Soc. Korea 17, 219-223 (2013)
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