Intraocular lens power calculation. A retrospective analysis of its practical value.

Two hundred and two consecutive intraocular lens (IOL) implantations, the lens power being predicted with the SRK-method, are retrospectively analyzed, and the factors possibly influencing the error in IOL power prediction are evaluated. The actual post-operative refraction is compared to the expected refraction for each IOL and to a hypothetical refraction that would have been obtained by a standard-power IOL implant. Axial length measurement and a high pre- and post-operative astigmatic error, along with low- and high power IOL predictions, are the factors that most influence the post-operative refractive error. A similar distribution of post-operative refraction could have been obtained by using a standard-power IOL instead of pre-operative calculation.