Table 2.

Summary of reliability estimates evaluated

Statistic	Equation
Intraclass correlation coefficient (ICC)	$B/B+W$
Mean absolute difference (MAD)	$|X_1-X_2|$
Technical error of measurement (TEM)	$\sqrt{\raisebox{1ex}{$\left(\sum D^2\right)$}\!\left/ \!\raisebox{-1ex}{$2N$}\right.}$
Relative error measurement (REM)	$MAD/X_3\times 100$
Relative TEM (% TEM or rTEM)	$TEM/X_3\times 100$

B between-measurement variance; W within measurement variance; [7] D difference between measurements; N number of eyes or subjects measured; X1 mean for rater 1 (session 1, or session 2 of capture 1); X2 mean for rater 2 (session 2, or session 2 of capture 2); X3 grand mean.