Corneal Biomechanical Changes after Crosslinking for Progressive Keratoconus with the Corneal Visualization Scheimpflug Technology

Table 4

Sample size calculation for the deflection-based parameters calculated using the new CST research software.

Parameter	Delta (Mean/SD)	Required sample size*
A1deflectionlength (mm)	−0.08 (0.53)	347
hcdeflectionlength (mm)	−0.03 (0.20)	350
A2deflectionlength (mm)	−0.26 (0.40)	21
hcdeflectionamp (mm)	0.003 (0.11)	10555
A1deflectionamp (mm)	−0.026 (0.06)	44
A2deflectionamp (mm)	−0.06 (0.16)	58
deflectionampmax (mm)	−0.018 (0.123)	368
deflectionampmax (ms)	0.43 (0.98)	43

Based on our data (, 3-month followup), this sample size is required to prove the differences with the -test at the significance level of 0.05 and a test power of 80%.