Factors significantly associated with the difference to the expected refractive outcome 3 months post-surgery.

The deepest ablation occurs circumferentially 3mm from the corneal centre. 3T refers to a point 3mm from the corneal centre in a horizontal direction temporally. Proportionate tissue ablated at 3T is depth of tissue ablated as a fraction of total corneal thickness at 3T. Proportionate corneal volume removed is the total number of pulses divided by the total corneal volume. Correction (Sph) correction spherical equivalent. Residual bed at 3T is residual bed thickness at 3T.