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Yu Kato, Makoto Inoue, Akito Hirakata; Quantification of the images obtained with Optos 200Tx and Optos California. Invest. Ophthalmol. Vis. Sci. 2018;59(9):1687.
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© ARVO (1962-2015); The Authors (2016-present)
To quantify the angle of view, the magnification, and the quality of images acquired with Optos 200Tx and Optos California.
We obtained fundus images of a model eye (constructed based on Gullstrand’s model of the human eye) with the Optos 200Tx and the Optos California to record the maximal scale imaged in each direction. We measured the length and the interval of the scale bars on a model eye at each angle and calculated the magnification.
The fundus image obtained with the Optos 200Tx covered 88 ± 1.1, 106 ± 0.5, 82 ± 2.1 and 107 ± 0.9° in the up, right, down, and left directions, respectively (n=10), while the Optos California covered 87 ± 3.6, 108 ± 3.4, 83 ± 3.7, 104 ± 2.0° (n=10). Horizontal angle of view obtained with the Optos 200Tx and the Optos California was 212° and 211° respectively (p=0.73). Vertical angle of view obtained with the Optos 200Tx and the Optos California was 171° and 170° respectively (p=0.47). Quantitative measurement showed that the posterior pole image is stretched 1.12-fold in the horizontal direction with respect to the vertical by the Optos 200Tx and 0.98-fold by the Optos California (p<0.05). The magnification with respect to the posterior pole increased quadratically in all directions, most steeply in the vertical direction, reaching 2.0 ± 0.02 × 1.5 ± 0.03 in the Optos 200Tx and 1.5 ± 0.03 × 1.4 ± 0.07 in the Optos California (p<0.05, tangential direction and radial direction respectively).
The Optos 200Tx and the Optos California can obtain an image with an angular range of approximately 210° horizontally and 170° vertically, with greatest limitation in the vertical direction. It should be noted that the most peripheral part of the image is significantly and unequally magnified, but the image obtained with the Optos California is improved with respect to the aspect ratio of the posterior pole and the magnification of the peripheral areas.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
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