Abstract: Toric intraocular lens (IOL) implantation has become the preferred method for astigmatism correction due to its high safety and predictability. Corneal astigmatism includes anterior corneal astigmatism (ACA) and posterior corneal astigmatism (PCA). In the past, corneal astigmatism was evaluated solely base on ACA measurement, which will induce an overcorrection in the with-the-rule corneal astigmatism eyes and an undercorrection in the against-the-rule astigmatism eyes. Therefore the important contribution of the PCA to total corneal astigmatism (TCA) should not be neglected. IOL Master and Lenstar 900 show high predictive and repeatability for keralometry measurement. Some devices which can measure the total keratometry directly is theoretically more accurate than the simulated keratometry. It is suggested that the SimK measured by IOL Master or Lenstar, matched with Barrett Toric formula directly if SimK is consistent well with TCA. The choice in case of poor consistency between SimK and TCA remains controversial. When PCA≥0.8 D, the measured PCA is recommended. At present, ophthalmologists should make individual selection according to the measurement of diverse devices and patients' conditions to minimize the residual astigmatism.(Int Rev Ophthalmol, 2022, 46: 437-442)

Key words: Fujian Natural Science Fundation (2019J01507)