The precision and agreement of corneal thickness and keratometry measurements with SS-OCT versus Scheimpflug imaging

Table 3 Intraobserver repeatability outcomes for corneal power obtained using CASIA swept-source optical coherence tomography in children

Parameter	Observer	Mean ± SD	S_w	TRT	CoV (%)	ICC (95% CI)
Km	1st	43.34 ± 1.43	0.10	0.28	0.23	0.995 (0.993 to 0.997)
Km	2nd	43.34 ± 1.43	0.11	0.30	0.25	0.994 (0.992 to 0.996)
J₀	1st	−0.70 ± 0.43	0.11	0.32	–	0.933 (0.904 to 0.954)
J₀	2nd	−0.73 ± 0.46	0.13	0.35	–	0.930 (0.900 to 0.952)
J₄₅	1st	0.00 ± 0.21	0.12	0.34	–	0.724 (0.630 to 0.804)
J₄₅	2nd	0.01 ± 0.23	0.14	0.37	–	0.715 (0.618 to 0.797)
Nasal 2 mm	1st	42.57 ± 1.36	0.23	0.64	0.55	0.971 (0.958 to 0.981)
Nasal 2 mm	2nd	42.54 ± 1.38	0.25	0.68	0.58	0.969 (0.955 to 0.979)
Superior 2 mm	1st	44.15 ± 1.62	0.26	0.72	0.59	0.975 (0.964 to 0.983)
Superior 2 mm	2nd	44.20 ± 1.65	0.36	1.00	0.82	0.953 (0.933 to 0.969)
Temporal 2 mm	1st	42.73 ± 1.37	0.25	0.70	0.59	0.967 (0.953 to 0.978)
Temporal 2 mm	2nd	42.72 ± 1.38	0.24	0.68	0.57	0.969 (0.956 to 0.979)
Inferior 2 mm	1st	43.94 ± 1.62	0.31	0.85	0.70	0.965 (0.949 to 0.976)
Inferior 2 mm	2nd	43.97 ± 1.65	0.25	0.70	0.58	0.977 (0.966 to 0.984)
Nasal 5 mm	1st	41.92 ± 1.38	0.25	0.69	0.59	0.968 (0.954 to 0.979)
Nasal 5 mm	2nd	41.91 ± 1.39	0.29	0.80	0.69	0.958 (0.940 to 0.972)
Superior 5 mm	1st	43.49 ± 1.71	0.48	1.32	1.10	0.926 (0.894 to 0.949)
Superior 5 mm	2nd	43.51 ± 1.65	0.43	1.18	0.98	0.936 (0.909 to 0.957)
Temporal 5 mm	1st	42.48 ± 1.40	0.30	0.83	0.70	0.956 (0.937 to 0.970)
Temporal 5 mm	2nd	42.47 ± 1.35	0.24	0.67	0.57	0.969 (0.955 to 0.979)
Inferior 5 mm	1st	43.47 ± 1.58	0.36	1.00	0.83	0.950 (0.928 to 0.966)
Inferior 5 mm	2nd	43.49 ± 1.60	0.36	1.00	0.83	0.951 (0.929 to 0.967)

Keratometric data are in units of diopter (D); SD = standard deviation, S_w = within-subject standard deviation, TRT = test-retest repeatability (2.77 S_w), CoV = within-subject coefficient of variation, ICC = intraclass correlation coefficient

ISSN: 2326-0254