Intraocular Lens Calculation Based on New Device for Intraoperative Aberrometry
Purpose
Comparison of an intraoperative IOL calculation based on the intraoperative aberrometric measurement to the preoperative IOL calculation with the Haigis formula.
Methods
21 eyes of 21 patients have been included in the study so far. Preoperative biometry was performed with the IOL-Master (Carl Zeiss Meditec, Germany) and the chosen IOL was calculated with the Haigis formula. During surgery aphacic aberrometry measurements have been performed with the I-O-W-A (Eye sight and Vision, Germany). The preoperative IOL calculation has been compared to a new IOL calculation formula based on the spherical equivalent measurement intraoperative.
Results
A congruence of 90% could be found for patients with an axial length between 22 to 25mm. For eyes with an axial length <22mm and >25mm a deviation up to ±1 D could be found.
Conclusion
Intraoperative aberrometry is fastly developing. First results are very promising but still some modification have to be done to provide exact values. One problem is the larger measurement zone intraoperatively compared to the IOL-Master measurement preoperatively. So far a correction factor of 0.5 D has to be used by comparing our 4mm measurement zone to the preoperative calculation with a measurement zone of 2.3mm.