Effects of Static Cyclotorsion Compensation of Refractive Outcomes and Level of Vision in Excimer Laser Surgery

Abstract

Purpose: To evaluate the reliability and reproducibility of static cyclotorsion compensation (SCC) measurements made by software of WaveLight EX500 Excimer laser in patients undergoing Laser-Assisted in Situ Keratomileusis (LASIK) procedure. Materials and Methods: A retrospective study was designed to compare the refractive and visual outcomes of LASIK procedure with or without SCC. Patients with astigmatism greater than or equal to 0.50 D that undergone LASIK surgery with SCC were included in the Group 1, without SCC were included in Group 2. The astigmatism of eyes in group 1 was also classifi ed according to axis as with the rule (WTR), against the rule (ATR) and oblique. The preoperative and postoperative spherical error, astigmatic error, and axis of astigmatism were compared between different groups. Subgroup analysis of group 1 was performed between different types of astigmatism groups. Results: Three hundred ninety-eight eyes of 199 patients were included in Group 1 and 126 eyes of 63 patients were included in Group 2. Postoperative spherical error was -0.003±0.36 (-1.00 +1.50) in group 1 and +0.11± 0.65 (-0.75 +1.50) in group 2 (p=0.04), Postoperative astigmatic error was -0.40±0.22 (-1.25 +0.50) in group 1 and -0.85± 0.22 (-1.25 -0.50) in group 2, (p=0.001). The mean magnitude of SCC was -0.95°±4.1. Postoperative astigmatic error was signifi cantly higher in WTR than ATR and oblique group (p=0.044, p=0.039, respectively) Conclusion: The cyclotorsion is reasonably compensated with using software of WaveLight EX500 Excimer in conjunction with the Wavelight Topolyzer Vario. Refractive outcomes could be better in the oblique group