J Korean Ophthalmol Soc.  2013 Jul;54(7):1091-1096. 10.3341/jkos.2013.54.7.1091.

Ocular Torsion Measured by Fundus Photographs and Optical Coherent Tomography in Normal Koreans

• Lee SH
• Kim SY

• KMID: 2217421
• DOI: http://doi.org/10.3341/jkos.2013.54.7.1091

Abstract

PURPOSE
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.
METHODS
Fundus photographs and optical coherence tomography were conducted in 400 eyes of 200 people with no ophthalmologic history. ImageJ(R) 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.
RESULTS
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.
CONCLUSIONS
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.

Keyword

Fundus photography; Ocular torsion; Optical coherence tomography

MeSH Terms

Eye
Optic Disk
Reference Values
Software
Tomography, Optical Coherence

Figure

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  Figure 1. (A) The measurement of disc foveal distance and angle. ‘a’ is horizontal optic disc center-foveal distance. ‘b’ is vertical optic disc center-foveal distance. ‘θ’ is the angle between the optic disc center and the fovea; tan θ = b/a. (B) The measurement of the optic disc center-foveal angle using ImageJ program. ‘a’ is a horizontal line drawn from the optic disc center. ‘b’ is a line drawn from the optic disc center to the fovea. ‘θ’ is the angle between the line a and b.

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  Figure 2. The measurement of the angle between the optic disc center and the fovea using Spectralis optical coherent tomography. Heidelberg eye explorer software provides fo-vea-to-disc alignment function which can accurately measure the angle between the optic disc center and the fovea.

Reference

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