Early visual quality outcomes after small-incision lenticule extraction surgery for correcting high myopic astigmatism

Abstract

Background To evaluate early optical quality outcomes after small-incision lenticule extraction (SMILE) surgery for correcting high myopic astigmatism. Methods This retrospective study enrolled 55 eyes from 37 patients who had preoperative myopic astigmatism of ≥2.00 diopters (D) who had been treated with SMILE surgery. Preoperatively, the mean cylinder was − 2.41 ± 0.54 D (range, − 2.00 D to − 4.50 D). The preoperative and postoperative visual outcomes, refraction, and higher-order aberration (HOA) at 1 and 3 months were compared. Refractive astigmatism changes were analyzed by the Alpins vector method. Results Three months after SMILE surgery, the average cylinder was − 0.14 ± 0.31 D, and the average astigmatism vector was − 0.09 D × 6.34°. The angle of error (AofE) was limited to within ±10°, and the magnitude of error was limited to within ±1.0 D in all patients. The correction index (CI) was 0.98 ± 0.07, the index of success (IOS) was 0.08 ± 0.13, and the flattening index (FI) was 0.97 ± 0.07. Significant positive correlations were found between IOS and |AofE| (P = 0.000); negative correlations were found between FI and |AofE| (P = 0.000). The postoperative total HOA, spherical aberration, vertical coma aberration, and trefoil 30° were increased significantly compared with preoperative measurements, and the increase in HOA was closely related to preoperative astigmatism (P < 0.05). Conclusions SMILE has preferable outcomes for correcting high myopic astigmatism. Axis rotation during the surgery might influence the undercorrection of astigmatism. The increase of HOA after surgery is related to preoperative astigmatism.

Comparison of cataract patients with regular corneal astigmatism after implantation of extended range-of-vision and bifocal toric intraocular lenses

“…ZMT IOL effectively tackled the astigmatism, but residual astigmatism persisted after ZXR00 IOL surgery. We found that astigmatism may increase high-order aberrations (23,24), mainly coma and trefoil (25), aligning with previous study findings. Additionally, the rotational stability design principle of ZMT IOL played a role in optimizing its objective visual quality.…”

Variability of astigmatism correction and corneal aberrations between two locations of cap side-cut after small-incision lenticule extraction: A randomized study

“…The safety and e cacy index were 1.01 ± 0.06 and 1.00 ± 0.08 in group 1 and 1.04 ± 0.14 and 1.02 ± 0.14 in group 2, respectively. The safety index was close to that reported in previous studies 17,18 , which reported a median safety index of 1 and 1.1, respectively, at the 3-month follow-up after SMILE surgery. Another study 19 reported an e cacy index of 1.18 ± 0.21, with a mean preoperative astigmatism of -0.68 ± 0.46 D, which was − 0.82.…”

Small incision lenticule extraction and femtosecond-assisted laser in situ keratomileusis in patients with deep corneal opacity: case series

“…SMILE has shown superior safety, efficacy, predictability, and visual quality [2][3] . Even among patients with high myopic astigmatism, corneal opacity, or thin cornea, SMILE also exhibited satisfactory performance [4][5][6] . Meanwhile, femtosecond-assisted laser in situ keratomileusis (FS-LASIK) was another classical and robust corneal surgery for refractive correction [7][8] .…”