Table 2. Pearson’s correlation coefficient R and agreement measurements for nerve-head fovea distances in left and right eyes.

Measurement	R	Mean	SDa	95% Limits of agreement and 95% CI
Center of the nerve-head				Lower limit & 95% CI	Upper limit & 95% CI
Three repeated measurements	0.958	0.0078	0.079	−0.147 (−0.167, −0.127)	0.163 (0.143, 0.182)
Single measurement			0.085	−0.159 (−0.180, −0.137)	0.174 (0.153,0.195)
Rim of the nerve-head				Lower limit & 95% CI	Upper limit & 95% CI
Three repeated measurements	0.963	0.0056	0.073	−0.137 (−0.156, −0.119)	0.149 (0.130, 0.167)
Single measurement			0.079	−0.150 (−0.170, −0.130)	0.161 (0.141,0.181)

^aSD for single measurements = √ [(SD difference for average of three measurements)²+ (SD within three measurements of observer 1)²+ (SD within three measurements of observer 2)²]