Comparing Refractive Prediction Accuracy of IOL Master 700 and Sirius Utilizing the Barrett Universal II Formula

To compare the refractive-prediction error (the difference between the predicted post-operative spherical equivalent and the actual spherical equivalent) of IOLMaster 700 and Sirius when their biometric data are fed into the Barrett Universal II formula.

Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.

Prospective, observational, single-center, paired-eye study.

123 eyes of 93 cataract patients were enrolled. The participants ranged in age from 36 to 91 years, with a mean age of 65.38 ± 14.84 years. Axial length from IOLMaster 700 and corneal curvature, anterior-chamber depth and white-to-white from both devices were entered into the BarErett Universal II calculator to obtain predicted post-operative spherical equivalent (PRP). One week after uneventful phacoemulsification with monofocal intraocular lens implantation, manifest refraction provided the actual spherical equivalent (SE). Prediction error (ΔPRE = PRP - SE) and absolute error |ΔPRE| were primary outcomes.

Both devices produced positive ΔPRE, but the median was lower for IOLMaster 700 than for Sirius (0.41 D vs 0.73 D; p < 0.05). Median |ΔPRE| was also smaller for IOLMaster 700 (0.61 D vs 0.80 D; p < 0.05). Eyes within ±0.50 D of target refraction numbered 45.5% for IOLMaster 700 versus 26.0% for Sirius (p < 0.05). Subgroup analysis showed no difference in error magnitude between long (AL > 25 mm) and normal axial-length eyes.

Under the Barrett Universal II formula, IOLMaster 700 yields more accurate refractive predictions than Sirius, with smaller systematic drift and absolute error, irrespective of axial length. Thus, IOLMaster 700 with Barrett Universal II is the preferred biometry for superior refractive accuracy. This study offers surgeons practical guidance for improving post-operative visual outcomes and patient satisfaction.