Vector Analysis Of High Astigmatism (≥2.0 Diopters) Correction After Small-Incision Lenticule Extraction With Stringent Head Positioning And Femtosecond Laser-Assisted Laser In Situ Keratomileusis With Compensation Of Cyclotorsion

The purpose of this study was to compare the astigmatic correction by vector analysis in patients with high myopic astigmatism after femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) with cyclotorsion compensation or small-incision lenticule extraction(SMILE) with stringent head positioning.

Beijing Aier-Intech Eye Hospital, Beijing, China.

A retrospective case series. Patients who had correction of myopic astigmatism of 2 diopters (D) or more treated with either FS-LASIK with cyclotorsion compensation or SMILE with stringent head positioning were included. The results of vision and refraction were analyzed and compared between groups with the right eye.

 

The study enrolled 94 eye in 94 patients (41eyes in an FS-LASIK and 53 eyes in a SMILE). The mean preoperative manifest cylinder was -2.65±0.77D in the FS-LASIK group and 2.51 ± 0.56D in the SMILE group (P = 0.302). At 12 months, there was no significant between-group difference in UDVA (P = 0.274). 78% and 66% of eyes in the FS-LASIK and SMILE groups were within 0.5 D postoperative cylinder, respectively ( P = 0.202). The vector analysis showed comparable between two-group TIA (P = 0.114), SIA (P = 0.057),  difference vector (DV, P = 0.069), and the angle of error (AE, P = 0 .213) values ; the index of success (IOS) was 0.18 in the FS-LASIK group and 0.24 in the SMILE group (P = 0.024), with a significant difference between the two groups.

FS-LASIK with compensation of cyclotorsion showed a favorable correction of high myopic astigmatism (≥2.0 D) compared to SMILE with stringent head positioning at 12 months.