Corneal biomechanical properties in myopic eyes evaluated via Scheimpflug imaging

BMC Ophthalmology

Table 2 All the parameters acquired by the Corvis ST

Parameters	Low myopia (n = 49)	Moderate myopia (n = 61)	High myopia (n = 91)	Severe myopia (n = 64)	P-value
A1-time (m/s)	7.07 ± 0.21	7.07 ± 0.18	7.12 ± 0.24	7.14 ± 0.26	0.212
A1-length (mm)	1.76 ± 0.16	1.73 ± 0.12	1.73 ± 0.08	1.72 ± 0.09	0.293
A1-velocity (m/s)	0.15 ± 0.01	0.15 ± 0.01	0.15 ± 0.01	0.15 ± 0.01	0.602
A2-time (m/s)	21.93 ± 0.45	21.79 ± 0.36	21.76 ± 0.43	21.66 ± 0.42	0.011
A2-length (mm)	1.72 ± 0.28	1.71 ± 0.30	1.60 ± 0.25	1.55 ± 0.28	0.001
A2-velocity (m/s)	−0.38 ± 0.08	−0.40 ± 0.07	− 0.42 ± 0.07	− 0.46 ± 0.08	< 0.001
HC-time (m/s)	16.89 ± 0.38	16.69 ± 0.35	16.72 ± 0.32	16.59 ± 0.30	< 0.001
PD (mm)	4.16 ± 0.79	4.35 ± 0.66	4.23 ± 0.72	4.24 ± 0.79	0.619
HC radius (mm)	6.51 ± 0.79	6.63 ± 0.69	7.02 ± 0.86	6.52 ± 1.02	< 0.001
DA (mm)	1.14 ± 0.11	1.12 ± 0.09	1.13 ± 0.10	1.18 ± 0.12	0.007

A1-time and A2-time: time from start until the first and second applanation; A1-length and A2-length: length of flattened cornea at the first and second applanation; A1-velocity and A2-velocity: corneal velocity during the first and second applanation; HC-time: time from start until highest concavity is arrived; PD: distance between the two peaks of the cornea at highest concavity; HC radius: central curvature at highest concavity; DA: maximum deformation amplitude at highest concavity. One-way analysis of variance (ANOVA) and LSD-t test was used to analyze the differences of corneal biomechanical parameters between the four groups. P < 0.05 was considered statistically significant

ISSN: 1471-2415