Comparison of optical biometry versus ultrasound biometry in cases with borderline signal-to-noise ratio

Figures & data

Figure 1 Different levels of signal quality resulting from optical biometry. Abbreviations: AL, axial length; SNR, signal-to-noise ratio.

Table 1 Mean, standard deviation and difference in mean of AL and IOL power from IOL Master and US biometry

	N (eyes)	Mean	SD	SE mean	Difference in mean	95% CI	P-value
IOL Master AL (mm)	27	24.391	1.0398	0.20012	0.055	(−0.013–0.1219)	0.054
US AL (mm)	27	24.336	0.9953	0.19155
Holladay I
IOL Master lens power (D)	27	20.148	2.6991	0.5194	0.092	(−0.127–0.312)	0.394
US lens power (D)	27	20.056	2.9034	0.5588
Hoffer Q
IOL Master lens power (D)	27	20.167	2.7210	0.5237	0.204	(−0.0307–0.4381)	0.086
US lens power (D)	27	19.963	2.9448	0.5667
SRK-T
IOL Master lens power (D)	27	20.167	2.5570	0.4921	0.130	(−0.0726–0.3319)	0.199
US lens power (D)	27	20.037	2.7663	0.5324
All average
IOL Master lens power (D)	27	20.130	2.7372	0.5268	0.093	(−0.1338–0.3190)	0.408
US lens power (D)	27	20.037	2.9218	0.5623

Abbreviations: IOL, intraocular lens; AL, axial length; US, ultrasound.

Table 2 Paired t-test comparing mean of AL obtained from IOL Master and US biometry

Axial length (mm)	P-value
Difference in mean equal to 0.1 mm	0.1769
Difference in mean equal to 0.03 mm	0.463

Abbreviations: IOL, intraocular lens; AL, axial length; US, ultrasound.

Figure 2 Box plots comparing corresponding data obtained from IOL Master and US biometry.

Notes: Left-sided values are obtained by IOL Master, and right-sided values are obtained by US biometry. (A) IOL calculation; (B) Axial length.
Abbreviations: IOL, intraocular lens; US, ultrasound.

Figure 3 Bland–Altman Plots demonstrating the agreement between IOL Master and US biometry.

Notes: (A) Bland–Altman plot for axial length. (B) Bland–Altman plot for IOL power using the Holladay 1 formula. (C) Bland–Altman plot for IOL power using the Hoffer Q formula. (D) Bland–Altman plot for IOL power using the SKR-T formula. (E) Bland–Altman plot for IOL power using the average of 3 formulae.
Abbreviations: IOL, intraocular lens; US, ultrasound.