AIM: To compare the difference of A-scan and IOL Master in intraocular lens power measurement.

METHODS: Two hundred and twenty-six patients(230 eyes)with age-related cataract were included in the study. Before surgery, axial length was measured by A-scan and IOL Master respectively and corneal curvature was measured by auto refractometer. Intraocular lens power was calculated according to the SRK-T formula. Corneal curvature was measured by auto refractometer and the refractive outcome was performed by phoropter three months after cataract surgery.

RESULTS: The mean axial length was(23.48±1.94)mm measured by A-scan and(23.75±1.96)mm measured by IOL Master. There was significant difference between them(P<0.05). After random grouping, the preoperative and postoperative mean corneal curvature in A-scan group was(43.94±1.81)D and(43.98±1.87)D respectively. There was no statistically significant difference between them(P>0.05). And the results were(44.10±1.57)D and(44.11±1.58)D in IOL Master group. There was no significant difference between them(P>0.05); The mean absolute refractive error(MAE)in A-scan group was(0.47±0.27)D and in IOL Master group(0.41±0.19)D. The difference was significant(P<0.05).

CONCLUSION: IOL Master is proved to be slightly more accurate than A-scan for IOL power calculation.