AIM: To analyze the consistency and accuracy of the axial position of the astigmatism correction intraocular lens(Toric IOL)measured by OPD scan Ⅲ(optical path difference analyzer)and the traditional slit lamp method.

METHODS: A prospective observational control study. A total of 118 patients with 156 eyes who underwent phacoemulsification combined with Toric IOL implantation in our hospital from July 2018 to October 2019 were selected. The residual astigmatism was followed up at 1wk, 1mo and 3mo after the operation, and the axial position of Toric IOL was measured with OPD scan Ⅲ under the small pupil(Axial intraocular astigmatism method)and after dilated pupils(Axial OPD method), while using traditional slit lamp method to measure Toric IOL axis position(Axial Slit method). Analyze the difference and consistency of the measurement results of the three methods, and calculate the Lens axis deviation(LAD)between the measurement results of the three methods and the target axis.

RESULTS: The residual astigmatism of the patients in this group was significantly lower than that before the operation at 1wk, 1mo and 3mo after operation(P<0.05). The proportion of residual astigmatism ≤ 0.75D at 3mo after surgery was 73.7%. Three months after the operation, the axial position of the Toric IOL measured by the axial Slit method, the axial OPD method, and the axial intraocular astigmatism method were: 111.0°(10, 178)°, 113.5°(12, 180)°, and 113.0°(15, 178)°. Consistency analysis showed that the average value of the difference between the axial OPD method and the axial Slit method, the axial intraocular astigmatism method and the axial slit method, the axial OPD method and the axial intraocular astigmatism method at 3mo after the operation, they were -0.58°, -0.19°, 0.40°, which were all close to 0°, with high consistency. 95% LoA were(-7.01-5.84)°,(-12.44-12.07)°,(-10.69-11.49)°. At 3mo postoperatively, the proportions of patients with LAD ≤5° measured by axial Slit method, axial OPD method, and axial intraocular astigmatism were 82.0%, 80.1%, and 59.0%, respectively.

CONCLUSION: OPD scan Ⅲ can directly measure Toric IOL axial position after dilated pupils. It was an objective and accurate measurement method, which can replace the traditional slit lamp method to measure axial position and avoid subjective limitations. The Toric IOL axial position can also be measured by intraocular astigmatism under the small pupil, which has certain practical application value in ophthalmology clinical work.