Journal of Clinical and Experimental Ophthalmology
Open Access

Abstract

Comparison of Manual and Automated Methods to Measure Position-Induced Ocular Cyclotorsion

Su-Yeon Kang, Jae-Won Lim, Hyo Myung Kim and Jong-Suk Song

Purpose: To evaluate position-induced ocular cyclotorsion with manual and automated methods and to compare the measurements of the two methods.

Setting : Department of Ophthalmology, Korea University College of Medicine, Seoul, Republic of Korea.

Methods : Position-induced ocular cyclotorsion was measured in 40 normal eyes using manual and automated methods. In the manual method, the subject was seated upright at the slit lamp, and the corneal limbus was marked at the 0- and 180-degree positions. Next, with the subject lying on the surgical table, ocular cyclotorsion was measured using a Mendez degree gauge (Katena Products Inc., Denville, NJ). In the automated method, new CRS Master TM with OcuLign TM eye registration (Carl Zeiss Meditec, Jena, Germany) was used.

Results: The mean values of ocular cyclotorsion were -0.53 ± 2.30 degrees with the manual method and 1.08 ± 2.61 degrees with the automated method (+: counterclockwise, -: clockwise). There was a significant difference between these two methods (p=0.002) and no significant correlation (r=0.201, p=0.213). On the Bland-Altman plots, the range of agreement between these two methods was 6.1 degrees, whereas the range of agreement between zero value which assumed there was no manually detectable cyclotorsion and automated measurements was 5.1 degrees; the range of agreement between zero value and automated method was 1 degree lower than the agreement range between manual and automated methods.

Conclusions: The current manual method, which has been used clinically to compensate for position-induced ocular cyclotorsion, is not correlated with automated method.