Table 4.

Vector analysis of changes in refractive cylinder stratified by the magnitude of preoperative cylinder

Vector parameter	All eyes		Preoperative cylinder (D)
	n=611		Mean (SD)
	Mean (SD)	Range	2.00–2.99	3.00–3.99	4.00–4.99	5.00–6.00
			n=410	n=130	n=53	n=18
IRC (D)	2.76 (0.81)	2.00–6.00	2.29 (0.27)	3.24 (0.26)	4.27 (0.27)	5.31 (0.30)
SIRC (D)	2.53 (0.80)	0.85–5.50	2.12 (0.44)	2.99 (0.44)	3.85 (0.54)	4.69 (0.59)
EV (D)	0.37 (0.38)	0.00–2.00	0.31 (0.33)	0.40 (0.41)	0.61 (0.46)	0.74 (0.55)
ER	0.13 (0.14)	0.00–0.78	0.14 (0.14)	0.12 (0.13)	0.14 (0.11)	0.14 (0.10)
CR	0.92 (0.14)	0.38–1.48	0.92 (0.15)	0.92 (0.12)	0.90 (0.12)	0.88 (0.11)
EM (D)	0.22 (0.40)	−1.25 to 1.71	0.17 (0.35)	0.25 (0.39)	0.42 (0.53)	0.62 (0.57)
EA (°)	−0.45 (2.99)	−22.33 to 10.78	−0.40 (3.06)	−0.53 (3.08)	−0.71 (2.42)	−0.14 (2.23)
Absolute EA (°)	1.52 (2.62)	0.00–22.33	1.49 (2.71)	1.57 (2.70)	1.64 (1.91)	1.41 (1.70)

Abbreviations: D, diopter; SD, standard deviation; IRC, intended refractive correction; SIRC, surgically induced refractive correction; EV, error vector; ER, error ratio; CR, correction ratio; EM, error of magnitude; EA, error of angle.