Table 1 Baseline characteristics of the study population

Eyes

 Number

1920

68

 Patients

960

40

Laterality (n, %)

 Right

960 (50%)

36 (53%)

 Left

960 (50%)

32 (47%)

Age (years)

 Mean ± SD

25.0 ± 2.8

26.0 ± 4.2

 Range

(21 to 37)

(21 to 35)

Sex (n, %)

 Male

326 (34%)

16 (40%)

 Female

634 (66%)

24 (60%)

Refraction SE (D)

 Mean ± SD

 − 5.50 ± 1.20

 − 1.42 ± 0.52

 Range

(− 2.50 to − 8.50)

(− 0.75 to − 2.50)

Sphere (D)

 Mean ± SD

 − 4.30 ± 1.32

 − 1.21 ± 1.10

 Range

 − 2.25 to − 7.75

 − 0.50 to − 2.10

Cylinder (D)

 Mean ± SD

 − 1.63 ± 0.82

 − 0.57 ± 0.50

 Range

 − 0.75 to − 2.75

0.00 to − 1.50

CCT (μm)

 Mean ± SD

530.0 ± 10.2

491.0 ± 13.2

 Range

(508 to 560)

(470 to 511)

K readings (D)

 Mean ± SD

43.0 ± 1.6

40.0 ± 1.3

 Range

(42 to 46)

(38 to 41)

CDVA (logMAR)

 Mean ± SD

0.26 ± 0.08

0.14 ± 0.06

 Range

(0.00 to 0.6)

(− 0.1 to 0.2)

CH

 Mean ± SD

10.40 ± 0.92

8.60 ± 1.56

 Range

(9.7 to 13.1)

(7.8 to 11.2)

CRF

 Mean ± SD

10.20 ± 1.24

9.20 ± 1.66

 Range

(9.6 to 13.3)

(8.3 to 11.5)