Matching results of the cases considered in the validation study.

x0, y0, z0 represent the translational displacements of corneal surface; α, β, γ represent the angular rotations about the three main axes (x, y and z); Pre-set means the artificial misalignments added to the corneal elevation data pre topography matching; Computed means the misalignments calculated using the ICP algorithm; Diff Ratio in percentages means the ratio of the difference compared with Pre-set misalignments Matching results of the cases considered in the validation study.