Comparing The Accuracy Of Pre-Operative Manual To Femtosecond Corneal Marking For Toric Intraocular Lenses Alignment

The wide use of toric IOL promote better refractive outcome for cataract surgery. To receive the accuracy we are aiming to most precise preoperative measurment. there isnt gold standart for preoperative coneal amrking for toric IOL axis. We would like to evaluate the visual and refractive outcomes of two preoperative marking methods of toric IOL axis in patients who are going through routine cataract surgery with toric IOL implantation. Two groups with manual marking and one group with Femtosecond marking. by comparing these methods we can identify which method achieve better accuarcy, examine the the variants is significant to the aligment. 

Retrospective reveiw of 350 patients' chart who had toric IOL implantation during phacoemulsification (CE/IOL), with or without FLACS (CATALYS laser system Johnson&Johnson vision) from 2018 to 2023 by two high volume surgeons. 

The comparison will be between control group which include patients how has manual marking axis marking before surgery. and study group would include patients who had femtosecond marking of axis, a third group would be a combed marking method. Pre-operative evaluation evaluation includes measurments by Lenstar LS900,IOL master700 and Pentacam and Atlas Topographer. All biometric measurments were compatible with the strict validation criteris by Hill-RBF calculator Version 2.0. The surgeon chose the implanted TIOL using Barret online toric calculator and IOL manufactures' online calculators. All devices was in agreement whne choosing the power and axis placment. Follou up with full dialted exam on day1,7,30. Axis deviation was measured. 

Three hundred and fifty eyes of 310 patients were included (group 1 of 190 eyes, group 2: 160 eyes). No difference in preoperative demographic or biometric data. The mean absolute toric aligment error (intended versus acheived) was 4 degree ± 4.3(SD) and in group 1 and in group 2 2 degre ± 2.2 (SD). Ninty two precent of patients in group1 and ninty five precents of group 2 achieved refractive astigmatism of 0.5D or less. The corneal astigmatism direction (wtr, atr, obl) did not influence the mean dgree of misaligment. We find no add value for group 3 with combined marking method

Femtosecond marking was more accurate then manual slit beam marking.