%0 Journal Article
%A Garzón Jiménez, Nuria
%A Rodríguez Vallejo, Manuel
%A Carmona González, David
%A Calvo Sanz, Jorge A.
%A Poyales Galán, Francisco
%A Palomino Bautista, Carlos
%A Zato Gómez de Liaño, Miguel Á
%A Fernández, Joaquín
%T Comparing surgically induced astigmatism calculated by means of simulated keratometry versus total corneal  refractive power
%D 2018
%@ 1120-6721
%U https://hdl.handle.net/20.500.14352/18444
%X Purpose: To evaluate surgically induced astigmatism as computed by means of either simulated keratometry (KSIM) or total corneal refractive power (TCRP) after temporal incisions.Methods: Prospective observational study including 36 right eyes undergoing cataract surgery. Astigmatism was measured preoperatively during the 3-month follow-up period using Pentacam. Surgically induced astigmatism was computed considering anterior corneal surface astigmatism at 3mm with KSIM and considering both corneal surfaces with TCRP from 1 to 8mm (TCRP3 for 3mm). The eyes under study were divided into two balanced groups: LOW with KSIM  astigmatism <0.90D and HIGH with KSIM astigmatism ≥0.90D. Resulting surgically induced astigmatism values were compared across groups and measuring techniques by means of flattening, steepening, and torque analysis. Results: Mean surgically induced astigmatism was higher in the HIGH group (0.31D @ 102°) than in the LOW group (0.04  D @ 16°). The temporal incision resulted in a steepening in the HIGH group of 0.15 D @ 90°, as estimated with KSIM,  versus 0.28 D @ 90° with TCRP3, but no significant differences were found for the steepening in the LOW group or for  the torque in either group. Differences between KSIM- and TCRP3-based surgically induced astigmatism values were  negligible in LOW group.Conclusion: Surgically induced astigmatism was considerably higher in the high-astigmatism group and its value was underestimated with the KSIM approach. Eyes having low astigmatism should not be included for computing the  surgicallyinduced astigmatism because steepening would be underestimated.
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