To investigate the normal range of ocular torsion in Koreans with no ophthalmologic history using fundus photographs and optical coherence tomography and compare the results of the two methods.

Fundus photographs and optical coherence tomography were conducted in 400 eyes of 200 people with no ophthalmologic history. ImageJ® was used to measure the center of the optic nerve head to foveal angle with fundus photographs. For optical coherence tomography, the fovea-to-disc alignment function in the computer program was used to automatically calculate the angle. Then, the calculated angles measured by the two different methods were compared.

In fundus photographs, the angle of the fovea from the center of the optic nerve head was 6.26 ± 2.92 degree in the right eye, 6.65 ± 2.58 degree in the left eye, and the mean value was 6.47 ± 2.76 degrees. From the automatic calculation in optical coherence tomography, the angle of the fovea from the center of the optic nerve head was 6.12 ± 3.00 degree in the right eye, 6.83 ± 2.70 degree in the left eye, and the mean value was 6.52 ± 2.83 degrees. There was no statistically significant difference between the results of the two different methods. In addition, no statistically significant difference was observed between the right and left eyes, sexes, or ages.

When comparing the conventional method of measuring ocular torsion with fundus photographs to optical coherent tomography, the fovea-to-disc alignment function of the optical coherent tomography may be useful to automatically calculate the cyclotorsion.