[Post-operatory biometry and refraction results estimated and refraction surprises--clinical study]

Preoperative biometry has a major influence on the success or failure of IOL implantation procedures. The paper wishes to demonstrate the significance of this manoeuvre for the refraction and visual outcome and for the postoperative satisfaction rate of the patients. The clinical study has rulled out for one year period and a number of 239 patients suffered a IOL implantation procedure (cataract or lens extraction for refractive purposes). The preoperative biometry was always necessary. We used one of the existing IOL power calculation formula (SRK II, SRK T, Holladay). The surgeon decided about the IOL power, always after discussing with the patient their postoperative refractive expectations. The postoperative refraction was, in the majority of cases, the estimated refraction and the errors were similar with those from the literature. Refractive surprises of several diopters were registered in high myopic and hyperopic eyes or in cases of coexisting ocular diseases which have modified the anatomical parameters of the eye. In conclusion, small errors in calculation can have large effects on visual outcome. This problem will be solved in the future, because the field is evolving rapidly driven by a new understanding of the anatomy of the eye and new hardware for measuring that anatomy.