Correlation of myopia onset and progression with corneal biomechanical parameters in children

Table 1 Comparison of general ocular measurement parameters among the three groups of subjects

	Number of cases	SE (D)	IOP (mmHg)	AL (mm)	CCT (μm)	Km
Myopia group	207	-2.543 ± 0.493	17.04 ± 2.88	25.61 ± 0.77	560.31 ± 36.13	43.15 ± 2.05
Emmetropia group	102	-0.104 ± 0.025	15.40 ± 2.09	23.35 ± 0.68	559.23 ± 38.43	43.05 ± 1.96
Hyperopia group	109	2.465 ± 1.025	15.32 ± 2.93	22.08 ± 0.79	561.92 ± 40.50	43.61 ± 2.34
F		2321	19.94	855.1	0.1364	2.279
P value		< 0.0001	< 0.0001	< 0.0001	0.8725	0.1036

SE: Spherical equivalent; IOP: Intraocular pressure; AL: Axial length; CCT: Central corneal thickness.

Table 2 Comparison of corneal biomechanical parameters among the three groups of subjects

	Number of cases	A1V (ms-1)	A1L (mm)	A1T (ms)	A1DA (mm)	A2V (ms-1)	A2L (mm)	A2T (ms)	A2D (mm)	HCT (ms)	HCR (mm)	PD (mm)	DA (mm)	IR	ARTh	SP-A1	CBI	TBI
Myopia group	207	0.13 ± 0.02	1.85 ± 0.29	7.63 ± 0.29	0.12 ± 0.01	0.29 ± 0.06	1.73 ± 0.39	21.33 ± 0.93	0.37 ± 0.08	16.70 ± 0.79	7.59 ± 0.73	3.42 ± 0.88	0.98 ± 0.09	9.23 ± 1.93	472.03 ± 131.43	102.01 ± 18.43	0.53 ± 0.35	0.56 ± 0.25
Emmetropia group	102	0.15 ± 0.05	1.93 ± 0.33	7.41 ± 0.22	0.13 ± 0.01	0.30 ± 0.02	1.70 ± 0.55	21.57 ± 1.24	0.41 ± 0.09	16.73 ± 0.49	6.42 ± 0.89	3.77 ± 0.92	0.99 ± 0.09	9.05 ± 2.61	451.61 ± 111.43	107.32 ± 14.62	0.23 ± 0.14	0.33 ± 0.23
Hyperopia group	109	0.14 ± 0.03	1.77 ± 0.39	7.39 ± 0.29	0.13 ± 0.02	0.31 ± 0.05	1.63 ± 0.53	21.35 ± 1.29	0.47 ± 0.13	16.59 ± 0.66	6.69 ± 1.02	3.02 ± 0.61	0.99 ± 0.10	11.34 ± 1.34	256.45 ± 46.34	108.42 ± 14.45	0.02 ± 0.01	0.12 ± 0.07
F		13.57	6.258	36.89	29.34	5.780	1.610	1.706	37.52	1.267	78.85	21.67	0.6079	47.99	145.7	6.681	150.6	158.2
P value		< 0.0001	0.0021	< 0.0001	< 0.0001	0.0033	0.2011	0.1829	< 0.0001	0.2829	< 0.0001	< 0.0001	0.5450	< 0.0001	< 0.0001	0.0014	< 0.0001	< 0.0001

A1V: First velocity of applanation; A1L: First applanation length; A1T: First applanation time; A1DA: First applanation deformation amplitude; A2V: Second velocity of applanation; A2L: Second applanation length; A2T: Second applanation time; A2D: Second applanation deformation; HCT: Time from the start until the highest concavity; HCR: Central curvature radius at highest concavity; PD: Peak distance; DA: Deformation amplitude; IR: Integrated radius; ARTh: ambrosia relational thickness-horizontal; SP-A1: First applanation stiffness parameter; CBI: Corvis biomechanical index; TBI: Topographic and biomechanics index.

Table 3 Correlation of corneal biomechanical parameters with general ocular measurement parameters

	SE (D)		IOP (mmHg)		AL (mm)		CCT (μm)		Km
	ρ	P value	ρ	P value	ρ	P value	ρ	P value	ρ	P value
A1V	-0.042	0.3917	0.053	0.2797	-0.003	0.9512	-0.583	< 0.0001	0.103	0.0353
A1L	0.033	0.5010	-0.061	0.2133	-0.077	0.1160	0.483	< 0.0001	-0.089	0.692
A1T	0.024	0.6246	-0.091	0.0631	-0.082	0.0941	0.562	< 0.0001	0.008	0.8705
A1DA	0.038	0.4384	-0.073	0.1362	0.053	0.2797	0.358	0.2367	0.048	0.3276
A2V	0.235	< 0.0001	-0.114	0.0197	0.302	< 0.0001	0.542	< 0.0001	0.043	0.3805
A2L	0.124	0.0112	-0.139	0.0044	-0.094	0.0548	0.382	< 0.0001	-0.117	0.0167
A2T	0.093	0.0575	-0.088	0.0723	-0.110	0.0245	0.421	< 0.0001	0.021	0.6686
A2DA	0.041	0.4031	-0.038	0.4383	0.074	0.1309	0.345	< 0.0001	0.033	0.5010
HCT	0.004	0.9350	-0.008	0.8705	-0.109	0.0258	0.049	0.3176	0.063	0.1986
HCR	0.009	0.8705	-0.039	0.4265	-0.049	0.3176	0.482	< 0.0001	-0.285	< 0.0001
PD	-0.130	0.0078	0.117	0.0167	0.545	< 0.0001	0.381	< 0.0001	-0.394	< 0.0001
DA	-0.119	0.0149	0.193	0.0001	0.038	0.4384	0.295	< 0.0001	0.234	< 0.0001
IR	-0.204	< 0.0001	0.244	< 0.0001	0.025	0.6103	0.421	< 0.0001	0.283	< 0.0001
ARTh	0.062	0.2059	-0.072	0.1417	0.017	0.7289	0.274	< 0.0001	-0.085	0.0826
SP-A1	0.032	0.5141	-0.024	0.6246	-0.059	0.2287	0.362	< 0.0001	0.008	0.8705
CBI	0.039	0.4265	-0.019	0.6985	-0.06	0.2209	0.385	< 0.0001	0.087	0.0756
TBI	0.027	0.5820	-0.020	0.6835	-0.016	0.7443	0.0235	< 0.0001	0.064	0.1916

SE: Spherical equivalent; IOP: Intraocular pressure; AL: Axial length; CCT: Central corneal thickness; A1V: First velocity of applanation; A1L: First applanation length; A1T: First applanation time; A1DA: First applanation deformation amplitude; A2V: Second velocity of applanation; A2L: Second applanation length; A2T: Second applanation time; A2D: Second applanation deformation; HCT: Time from the start until the highest concavity; HCR: Central curvature radius at highest concavity; PD: Peak distance; DA: Deformation amplitude; IR: Integrated radius; ARTh: ambrosia relational thickness-horizontal; SP-A1: First applanation stiffness parameter; CBI: Corvis biomechanical index; TBI: Topographic and biomechanics index.

Table 4 Correlation between spherical equivalent, intraocular pressure, and axial length growth and the change in corneal biomechanical parameters in subjects in the myopic group

	ΔSE (D)		ΔIOP (mmHg)		ΔAL (mm)		CCT (μm)		Km
	ρ	P value	ρ	P value	ρ	P value	ρ	P value	ρ	P value
ΔA1V	-0.0391	0.5758	0.0460	0.5107	-0.0032	0.9631	-0.5873	< 0.0001	0.1010	0.1478
ΔA1L	0.0370	0.5962	-0.0673	0.3350	-0.0818	0.2415	0.4236	< 0.0001	-0.0716	0.3053
ΔA1T	0.0257	0.7133	-0.0917	0.1889	-0.0909	0.1926	0.4629	< 0.0001	0.0080	0.9084
ΔA1DA	0.0344	0.6230	-0.0586	0.4013	0.0455	0.5147	0.3530	< 0.0001	0.0475	0.4966
ΔA2V	0.2027	0.0034	-0.1075	0.1232	0.3121	< 0.0001	0.5029	< 0.0001	0.0472	0.4994
ΔA2L	0.1397	0.0446	-0.1459	0.0360	-0.0971	0.1640	0.4505	< 0.0001	-0.0972	0.1637
ΔA2T	0.0772	0.2691	-0.0718	0.3042	-0.0897	0.1987	0.4920	< 0.0001	0.0244	0.7268
ΔA2DA	0.0462	0.5089	-0.0321	0.6459	0.0677	0.3327	0.3561	< 0.0001	0.0331	0.6357
ΔHCT	0.0035	0.9601	-0.0073	0.9171	-0.1120	0.1082	0.0465	0.5061	0.0717	0.3047
ΔHCR	0.0081	0.9073	-0.0323	0.6446	-0.0508	0.4669	0.5378	< 0.0001	-0.3190	< 0.0001
ΔPD	-0.1331	0.0559	0.1361	0.0505	0.4427	< 0.0001	0.3246	< 0.0001	-0.3320	< 0.0001
ΔDA	-0.1130	0.1049	0.1814	0.0089	0.0391	0.5763	0.2474	0.0003	0.2125	0.0021
ΔIR	-0.1841	0.0079	0.2674	0.0001	0.0228	0.7439	0.4886	< 0.0001	0.2615	0.0001
ΔARTh	0.0542	0.4378	-0.0671	0.3365	0.0164	0.8150	0.3274	< 0.0001	-0.0726	0.2983
ΔSP-A1	0.0372	0.5951	-0.0209	0.7655	-0.0623	0.3727	0.4282	< 0.0001	0.0074	0.9161
ΔCBI	0.0321	0.6461	-0.0160	0.8187	-0.0534	0.4450	0.3329	< 0.0001	0.1010	0.1474
ΔTBI	0.0234	0.7378	-0.0187	0.7888	-0.0143	0.8381	0.0247	0.7238	0.0589	0.3988

SE: Spherical equivalent; IOP: Intraocular pressure; AL: Axial length; CCT: Central corneal thickness; A1V: First velocity of applanation; A1L: First applanation length; A1T: First applanation time; A1DA: First applanation deformation amplitude; A2V: Second velocity of applanation; A2L: Second applanation length; A2T: Second applanation time; A2D: Second applanation deformation; HCT: Time from the start until the highest concavity; HCR: Central curvature radius at highest concavity; PD: Peak distance; DA: Deformation amplitude; IR: Integrated radius; ARTh: ambrosia relational thickness-horizontal; SP-A1: First applanation stiffness parameter; CBI: Corvis biomechanical index; TBI: Topographic and biomechanics index.