Purpose To estimate the treatment effectiveness of femtosecond-assisted laser in situ keratomileusis (FS-LASIK) and Toric implantable collamer lens (Toric ICL) for moderate and high astigmatism via vector analysis. Materials and Methods The study involved 44 eyes from 44 patients who had a preoperative refractive cylinder ≥1.0 diopters (D) and underwent bilateral FS-LASIK or Toric ICL surgery. The examinations included corrected distance visual acuity measurement and subjective refraction before and 3 months after surgery. The astigmatic changes were estimated using vector analysis. Results No statistically significant differences were found in cylindrical refraction and percentage of spherical equivalent within 0 D, ±0.50 D, ±1.00 D, and ±1.50 D between the FS-LASIK and Toric ICL groups at 3 months after surgery. The parameters of the vector analysis included intended refractive correction, surgically induced refractive correction, error vector, correction ratio, error ratio, error of magnitude, and error of angle, with no significant differences between the groups. However, error ratio the of the off-axis correction in the FS-LASIK and Toric ICL groups was 4.11 ± 3.02 and 8.11 ± 3.82, respectively, and the difference was significant (t = −2.46, p=0.02). Conclusion Both FS-LASIK and Toric ICL were effective for correcting moderate and high astigmatism, although Toric ICL might produce a larger error of angle than FS-LASIK when an off-axis correction occurs.

Purpose. To confirm the relationship between anterior chamber angle (ACA) and intraocular pressure (IOP) early after V4c implantable collamer lens (ICL) implantation. Methods. Patients were assigned to two groups: (1) right eyes (control group) and (2) left eyes (experimental group), with miosis conducted immediately after ICL implantation in the left eyes. IOP, angle opening distance (AOD), trabecular-iris angle (TIA), and pupil diameter (PD) were compared between two groups at postoperative hours 1, 2, and 24. The relationship between ACA, PD, and IOP was analyzed by multiple linear regression. Result. Thirty-six eyes of 18 patients were enrolled. The prevalence of ocular hypertension (OHT, defined as IOP ≥ 21 mmHg) was 61.11% and 16.67% in the right and left eyes, respectively, (χ2 = 7.481, p=0.006). At postoperative hours 1 and 2, IOP and PD were significantly higher p<0.001 in the right eyes, and TIA and AOD were significantly lower p<0.05 in the right eyes than in the left eyes. There was no significant difference at 24 h postoperative in these parameters. After the right eye ICL implantation, the changes of AOD 500 and PD were both linearly correlated with postoperative IOP change (β = −23.707 and 1.731, respectively; p = 0.013 and 0.002, respectively). Conclusion. The ACA was significantly narrowed immediately after V4c ICL implantation. There was a negative linear correlation between ACA and early IOP and a positive linear correlation between PD and early IOP. We recommend the use of intracameral miotics immediately after V4c ICL implantation to reduce the incidence of IOP spikes.