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. 2016 Autumn;5(3):89–95.

Table 2.

Comparisons of Pre- and Postoperative Visual Acuity, Refractive and keratometric variables

Variable Preoperative values Postoperative values P value
UDVA (logMAR)
     Mean ± SD 1.14 ± 0.32 0.35 ± 0.24 < 0.001
     Range 0.40, 1.6 0.0, 1.0
CDVA (logMAR)
     Mean ± SD 0.47 ± 0.20 0.22 ± 0.15 < 0.001
     Range 0.1, 1.0 0.0, 0.7
Sphere(D)
     Mean ± SD -8.18 ± 2.58 -0.32 ± 2.15 < 0.001
     Range -15, -6 -5.5, 3.5
Cylinder(D)
     Mean ± SD -4.59 ± 1.86 -2.00 ± 1.51 < 0.001
     Range -9.5, -0.6 -5.0, 1.5
Spherical equivalent(D)
     Mean ± SD -10.51 ± 2.81 -1.32 ± 2.29 < 0.001
     Range -17.37, -6.3 -7.0, 2.25
K max (D) 53.62 ± 3.57 48.96 ± 3.55 < 0.001
K min (D) 48.58 ± 3.16 46.15 ± 3.78 < 0.001
K mean (D) 51.06 ± 3.26 47.51 ± 3.57 < 0.001

UDVA: uncorrected distance visual acuity, logMAR: Logarithm of the Minimum Angle of Resolution, CDVA: corrected distance visual acuity, D: diopter, Kmax: maximum keratometry value in D, Kmin: minimum keratometry value in D, Kmean: mean keratometry value in D. Based on the previously mentioned guidelines, a 5-mm-diameter MyoRing was used for 21 eyes (65.6%) and a 6-mm-diameter MyoRing was used for the remaining 11 eyes. The between-group differences in the median changes at 3 months after surgery in sphere and spherical equivalent were significant (Table 3). The median change in sphere for the 5- and 6-mm-diameter MyoRing groups was 8.5 and 6 D, respectively (P = 0.027), and the median change in spherical equivalent for the 5- and 6-mm-diameter MyoRing groups was 10 and 7 D, respectively (P = 0.027). However, the between-group differences in the median changes in UDVA, CDVA, and cylinder were not significant (Table 3).