Table 2.

Calculated change in the astigmatic power (DC, diopters) and axis (°) with reference to the results obtained during routine subjective refraction and Orbscan II analysis of the corneal back surface (CBS) over 3 and 5 mm central zones.

	1 and 2 months (n = 36)	2 and 3 months (n = 19)
Subjective refraction, power (DC)	1.03 (0.59), 0.83–1.23	0.77 (0.38), 0.58–0.96
FSA, 3 mm	0.69 (0.59), 0.45–0.92	0.52 (0.44), 0.34–0.74
BSA, 3 mm	3.48 (3.11), 2.43–4.53	3.13 (2.72), 1.82–4.44
FSA, 5 mm	0.93 (0.81), 0.67–1.19	0.81 (0.57), 0.55–1.06
BSA, 5 mm	4.39 (3.62), 3.17–5.62	3.24 (2.14), 2.21–4.27
Subjective refraction, axis (°)	81.3 (58.1), 61.6–101.0	84.0 (73.2), 48.8–119.2
FSA, 3 mm	80.6 (59.9), 56.7–104.6	96.9 (55.0), 72.1–121.9
BSA, 3 mm	87.8 (57.8), 68.2–107.4	109.6 (56.4), 82.4–136.8
FSA, 5 mm	97.3 (61.5), 77.2–117.4	88.5 (56.9), 63.0–114.1
BSA, 5 mm	87.7 (50.5), 70.6–104.8	97.6 (41.6), 77.6–117.7

The mean (±SD) and lower and upper limits of the 95% confidence interval are shown for those cases where vector analysis revealed that the change in astigmatism determined by subjective refraction was ≥0.50 DC over the course of the noted periods. FSA = change in front surface astigmatism, over central 3 and 5 mm optical zones. BSA = change in Back surface astigmatism, over central 3 and 5 mm optical zones.