Topographic and surgical risk factors for high postoperative residual astigmatism after small incision lenticule extraction in patients with different degrees of myopia: a retrospective cohort study

Table 4 Specific risk factors for high postoperative residual astigmatism in high myopia population in comparison to low myopia population

Covariate (reference: low myopia group)	Coefficient	95% CI		P
Covariate (reference: low myopia group)	Coefficient	Lower limit	Upper limit	P
Age	0.003	-0.019	0.062	0.908
Sex	-0.006	-0.099	0.076	0.820
Cycloplegic refraction
SE	-0.001	-0.104	0.116	0.882
Sphere	0.101	-1.147	1.782	0.657
Cylinder	0.608	0.229	1.411	0.002*
Axis	-0.011	-0.109	0.038	0.431
IOP	0.016	-0.051	0.136	0.082
BCVA	0.008	-1.550	2.055	0.400
Manifest refraction
SE	0.015	-0.026	0.073	0.902
Sphere	0.044	-0.092	0.137	0.663
Cylinder	0.085	-0.016	0.150	0.078
Axis	0.136	-0.017	0.283	0.091
Steep corneal curvature	0.078	-0.034	0.159	0.202
Flat corneal curvature	-0.008	-0.011	0.019	0.824
Topographic cylinder	0.082	0.036	0.157	0.013*
Topographic axis	-0.004	-0.147	0.233	0.661
CCT
Apex	-0.016	-0.212	0.219	0.836
Thinnest	-0.022	-0.321	0.214	0.567
Difference	0.000	-0.013	0.013	0.999
ISV	0.009	-0.011	0.025	0.375
IHD	0.018	-0.007	0.030	0.096
Angle Kappa	0.011	-0.004	0.027	0.082
Lenticule thickness	0.001	-0.009	0.011	0.969
Optic zone	-0.094	-0.147	0.035	0.081
Incision length	0.558	0.136	2.322	0.003*

BCVA: best-corrected visual acuity, CCT: central corneal thickness, CI: confidence interval, IHD: index of height decentration, IOP: intraocular pressure, ISV: index of surface variance, N: number, SE: spherical equivalent
* Denotes a significant difference between groups

ISSN: 1471-2415