Table 2.

Limits of agreement and intraclass correlations.

Parameter	Intrameasurement standard deviation (Sw)	Precision (1.96 × Sw)	Repeatability (2.77 × Sw)	Intraclass correlation (ICC)	ICC 95% limits (lower)	ICC 95% limits (upper)
Central corneal thickness (μ)	2.56	5.02	7.09	0.997	0.995	0.998
Minimum corneal thickness (μ)	2.87	5.62	7.95	0.996	0.994	0.997
Horizontal visible iris diameter (mm)	0.03	0.06	0.08	0.997	0.996	0.998
Corneal apex thickness (μ)	4.21	8.27	11.69	0.996	0.994	0.997
Corneal apex curvature (dioptres)	0.23	0.45	0.64	0.995	0.992	0.996
Anterior chamber depth (mm)	0.03	0.06	0.09	0.995	0.992	0.997
Anterior chamber volume (mm3)	3.34	6.55	9.26	0.988	0.982	0.992
Iridocorneal angle (°)	0.95	1.86	2.63	0.970	0.955	0.980
Horizontal anterior chamber depth (mm)	0.06	0.12	0.16	0.964	0.947	0.976
Corneal volume (mm3)	0.69	1.36	1.92	0.973	0.960	0.982

Sw is intrameasurement standard deviation, computed as: $s_w^2=1/2n\sum d_i^2$. Where, n is the number of cases, and di is the difference between two measurement for the same subject i.¹⁷, ¹⁸, ¹⁹

Statistical precision is the difference between a subject's measurement and the true value for 95% of observations and was defined as 1.96 × Sw.¹⁷, ¹⁸, ¹⁹

Repeatability was defined as 2.77 × Sw (= √2 * 1.96 * Sw). The difference between the two observations for the same candidate is expected to be less than the value noted for repeatability for 95% pairs.¹⁷, ¹⁸, ¹⁹