Patients who had received phacoemulsification surgery with or without implantation of toric IOL are with a certain amount of corneal astigmatism.

The total corneal astigmatism, anterior chamber depth, will be measured by a Scheimpflug tomographer. Pupil size will be measured by itrace device and MONCV3 device. Residual astigmatism will be tested by subjective refraction.

The vectorial difference between measured corneal astigmatism (under multiple different region mode settings) and actual corneal astigmatism.

pupil size of patients in a bright environment measured by itrace device and MONCV3 device

pupil size of patients measured by Pentacam HR device

residual astigmatism tested by subjective refraction

Total corneal astigmatism measured by a scheimpflug tomographer under different region mode settings.

The distance between corneal apex and anterior surface of IOL measured by a scheimpflug tomographer

actual corneal astigmatism is derived from residual astigmatism at corneal plane and cylindrical power of IOL at corneal plane through Holladay 2 formula.