Comparison of two different devices to assess intraocular lenses

In this paper, we have compared the performance of two commercial systems, Kaleo-I and IOLA Plus, in the characterization of monofocal intraocular lenses (IOLs) according to the International Standard requirements (ISO 11979-2). The dioptric power (DP) and the Modulation Transfer Function (MTF) at 100 lp/mm and 3.0 mm aperture have been measured with both instruments in twenty commercial monofocal HEMA IOLs and their agreement was assessed by Bland Altman analysis. Compared with the designed power, IOLA Plus gave lower values in 85% of measures; Kaleo I errors are dependent on the power of the lens: measurements were higher than the designed power in the low-medium power range and lower than the labelled power in the high-power range. Differences in the MTF measurements between instruments were statistically significant, with an agreement of ±0.12 within the 95% confidence interval. IOLA Plus was very much reliable than Kaleo I in DP measurements. On the other hand, the reliability in the MTF measurements was similar for both instruments.