Zeiss CIRRUS HD-OCT 500, User Manual

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CIRRUS HD-OCT User Manual 2660021169012 Rev. A 2017-12
Appendix
B-11
For the closest distance to the fovea measurements using the automated algorithm, the
repeatability limit of the 200x200 scan was more repeatable compared to the 512x128
scan (0.2070 and 0.3492 mm respectively). Likewise, the reproducibility limit of the
200x200 scan was smaller compared to that of the 512x128 scans (0.2133 and 0.3520 mm
respectively) as shown in
Table B-10 .
Table B-10: Repeatability and Reproducibility of the Closest Distance to Fovea
Automated Algorithm
Prior to the manual editing of the algorithm, each scan was checked to ensure that they
were centered correctly on the fovea using the tools in Macular Thickness Analysis.
Table B-11 shows the repeatability and reproducibility of the closest distance to the fovea
after manual editing of the 200x200 scans. Note that there was a significant improvement
in the repeatability and reproducibility values for these measurements.
Table B-11: Repeatability and Reproducibility of the Closest Distance to Fovea
Manually Edited
Scan
Repeatability Reproducibility
Repeatability
SD (mm)
Repeatability
Limit
a
(mm)
Reproducibility SD
(mm)
Reproducibility
Limit
b
(mm)
200x200 Scan 0.0739 0.2070 0.0762 0.2133
512x128 Scan 0.1247 0.3492 0.1257 0.3520
a. Repeatability Limit is the upper 95% limit for the difference between repeated results. Per ISO 5725–1 and ISO 5725–6, Repeat-
ability Limit = 2.8 x Repeatability SD.
b. Reproducibility Limit is the upper 95% limit calculated for the difference between individual measurements using different oper-
ators and instruments. Per ISO 5725–1 and ISO 5725–6, Reproducibility Limit = 2.8 x Reproducibility SD.
Scan
Repeatability Reproducibility
Repeatability
SD (mm)
Repeatability
Limit
a
(mm)
Reproducibility SD
(mm)
Reproducibility
Limit
b
(mm)
200x200 Scan 0.0354 0.0990 0.0439 0.1229
a. Repeatability Limit is the upper 95% limit for the difference between repeated results. Per ISO 5725–1 and ISO 5725–6, Repeat-
ability Limit = 2.8 x Repeatability SD.
b. Reproducibility Limit is the upper 95% limit calculated for the difference between individual measurements using different oper-
ators and instruments. Per ISO 5725–1 and ISO 5725–6, Reproducibility Limit = 2.8 x Reproducibility SD.