Long-Term Visual Quality and Pupil Changes after Small-Incision Lenticule Extraction for Eyes without Preoperative Cylinder Refraction

Table 4

The preoperative clinical parameter comparison between group one and group two.

	Group one	Group two	value
	(n = 25)	(n = 8)
Pre. sphere (D)	−4.07 ± 1.39	−4.78 ± 1.38	0.215
Male-to-female ratio	1.27	0.33	0.131
Pre. central corneal thickness (µm)	540.95 ± 20.83	546.13 ± 26.48	0.591
Cap thickness (µm)	129.47 ± 2.29	127.50 ± 4.63	0.147
Cap diameter (µm)	7.63 ± 0.16	7.65 ± 0.21	0.801
Lenticular thickness (µm)	78.05 ± 15.36	95.88 ± 19.78	0.018
Pre. (D)	43.03 ± 1.44	43.96 ± 1.46	0.135
Pre. astig. power (D)	−0.78 ± 0.52	−0.98 ± 0.48	0.385

Note. . Pre.: preoperative; : mean keratometry of cornea; astig.: astigmatism. Group one means the group involved eyes without postoperative cylinder regression at 30 months, which also means that in this group, both the preoperative and the 30-month postoperative cylinder refraction was zero. Group two means the group involved the other eyes having postoperative cylinder regression no less than 0.25 D, which also means that in this group, the preoperative cylinder refraction was zero, while the postoperative cylinder refraction was ≥0.25 D or ≤−0.25 D.