AIM: To compare corneal curvature and astigmatism values identified with OPD-Scan Ⅲ, IOL Master, Pentacam and KR-8900 in cataract patients and to evaluate the consistencies and differences.

METHODS: In this prospective clinical trial, 45 cataract patients(86 eyes), received treatment at the Department of Ophthalmology in our hospital from April 2017 to June 2017, underwent corneal parameters measurements with four instruments: OPD-Scan Ⅲ, Pentacam, IOL Master, and KR-8900. Measurements included corneal curvature(K₁, K₂, K_m)and astigmatism parameters. The results were assessed using the paired samples t tests, Pearson coefficient, and Bland-Altman plots.

RESULTS: The difference of K₁ value measured by OPD-Scan Ⅲ and IOL Master was significant(P<0.001). Significant differences were also found in K₂ and K_m values between OPD-Scan Ⅲ and Pentacam or IOL Master(P<0.05), while others had noncomparable results(P>0.05). All biometry measurements revealed good liner correlation(r=0.408-0.980, P<0.001). The Bland-Altman showed that the corneal curvature and astigmatism vectors examined by OPD-Scan Ⅲ and all other devices had non-comparable results, except for the comparison of K₁, K₂ and K_m measured by OPD-Scan Ⅲ and KR-8900.

CONCLUSION: OPD-Scan Ⅲ and KR-8900 can be interchangeable for the measurements of corneal curvature, while the others are not directly interchangeable. The astigmatic results obtained from OPD-Scan Ⅲ are not completely interchangeable with KR-8900, IOL Master or Pentacam.