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. Author manuscript; available in PMC: 2012 Jan 1.
Published in final edited form as: Optom Vis Sci. 2011 Jan;88(1):140–149. doi: 10.1097/OPX.0b013e3181fc3467

Table 4.

Inferences from the Bland-Altman plots (Figure 2) to assess agreement between HRT-I and HRT-II exam pair acquired on the same day in the HRT-1vs2 study group (n = 344).

Without parabolic error correction Using the HRT parabolic error correction Using the modified parabolic error correction
Parameter Bias (95% CI) % eyes with
differences within
the clinical limits
of agreement		 Outliers* Bias (95% CI) % eyes with
differences within
the clinical limits of
agreement		 Outliers* Bias (95% CI) % eyes with
differences within
the clinical limits of
agreement		 Outliers*
Global rim area
(mm2)		 0.0643
(0.0537, 0.0750)		 95.06%
(327 eyes)		 0.87%
(3 eyes)		 0.0466
(0.0369, 0.0563)		 95.06%
(327 eyes)		 0%
(0 eyes)		 0.0483
(0.0385, 0.0581)		 96.8%
(333 eyes)		 0%
(0 eyes)
Global rim volume
(mm3)		 0.0202
(0.0141, 0.0264)		 97.09%
(334 eyes)		 0.58%
(2 eyes)		 0.0134
(0.0081, 0.0188)		 97.67%
(336 eyes)		 0.29%
(1 eyes)		 0.0132
(0.0077, 0.0187)		 97.67%
(336 eyes)		 0%
(0 eyes)
Global cup area
(mm2)		 (−0.0447 −
0.0290×mean)† 		95.06%
(327 eyes)		 1.16%
(4 eyes)		 −0.0466
(−0.0563, −0.0369)		 95.06%
(327 eyes)		 0.29%
(1 eyes)		 (−0.0483 −
0.0581 ×mean)† 		96.8%
(333 eyes)		 0%
(0 eyes)
Global cup volume
(mm3)		 (−0.0083 −
0.0524×mean)† 		96.51%
(332 eyes)		 1.16%
(4 eyes)		 −0.0089
(−0.0128, −0.0050)		 96.22%
(331 eyes)		 0.58%
(2 eyes)		 (−0.0061 −
0.0283×mean)† 		95.93%
(330 eyes)		 0.87%
(3 eyes)
Mean RNFL
thickness (mm)		 0.0072
(0.0035, 0.0110)		 97.67%
(336 eyes)		 0%
(0 eyes)		 0.0047
(0.0014, 0.0081)		 97.97%
(337 eyes)		 0%
(0 eyes)		 0.0045
(0.0011, 0.0080)		 98.26%
(338 eyes)		 0%
(0 eyes)
*

Outliers: % eyes with stereometric parameter differences within the 95% limits of agreement, but were outside the corresponding clinical limits of agreement

†

Regression based bias estimate