ISSN: 2155-9570
Qiu-Jian Zhu, Xiao-Ying Xing, Wei-Jian Zhu, Man-Hui Zhu, Lie Ma, You Yuan
Background: To compare the visual and refractive outcomes, vault and rotational stability between horizontal and vertical toric Implantable Collamer Lens (ICL) placement.
Materials and methods: This retrospective case-control study comprised 36 eyes of 36 patients with vertical toric ICL placement and 36 eyes of 36 patients with horizontal placement. The two groups were matched strictly 1:1 from January 2020 to October 2020. The visual acuity, vault, manifest refraction, Efficacy Index (EI), Safety Index (SI), vector analysis and rotational stability were compared between the two groups.
Results: Residual astigmatism in the vertical group was slightly smaller than that in the horizontal group (P=0.024) and the Index of Success (IOS) was slightly greater in the vertical group than in the horizontal group (P=0.013). Furthermore, the vault was significantly higher in the horizontal placement group than in the vertical placement group (P<0.001). Compared to the preoperative design, the absolute degree of rotation at 3 months postoperatively was 3.44° ± 2.72° for the horizontal group and 4.83° ± 2.93° for the vertical group. However, if the reference was changed to 2 hours postoperatively, the absolute rotation degree was 1.81° ± 1.84° for the horizontal placement group and 1.97° ± 1.70° for the vertical placement group. There was no significant difference in other parameters between the two groups.
Conclusion: Vertical placement of a toric ICL can have clinical effects and rotational stability as good as those with horizontal placement. Moreover, compared with horizontal placement, vertical placement can effectively reduce vault.