[Optical biometry of eyes corrected by phakic intraocular lenses]

The aim of this study was to determine whether eye length measurements obtained with the IOL Master (Zeiss Humphrey) before and after phakic IOL implantation would show any changes.

In a prospective study, we used the IOL Master to measure optical biometry in 25 myopic eyes of 15 patients before and after phakic IOL implantation (PRL, ICL, Artisan). The differences between both axial length measurements were calculated and compared using a nonparametric Wilcoxon test.

The difference between the preoperative and postoperative measurements ranged from -0.16 mm to 0.06 mm and averaged -0.016 mm, which was not statistically significant (p=0.20). Both measurements correlated in a highly positive manner (r=0.999; p<0.0001). The reproducibility of the preoperative and postoperative axial length measurements was very high (coefficient of variation=0.09% and 0.07%, respectively). The precision was 26 microm for preoperative measurements and 19 microm for postoperative measurements.

Our results showed that postoperative measurements of axial length are highly comparable to preoperative measurements and that optical biometry can achieve highly precise and reliable axial length measurements in eyes with phakic IOLs. This application becomes clinically relevant in evaluating eyes with phakic IOLs that might require cataract surgery. Hence, accurate axial length measurements in eyes with phakic IOLs will be extremely important when cataract occurs in these eyes and when the preoperative measurements are no longer available.