Rotational Stability And Vault Outcomes Of Evo Icl Using Oblique Vs. Horizontal/Vertical Implanting Orientation: A Prospective Controlled Pilot Study

To evaluate the early outcomes of EVO ICL using oblique implanting orientation, focusing on rotational stability, vault predictability, and refractive efficacy compared to horizontal and vertical implanting orientations.

It is a prospective case series

In this prospective case series, 348 eyes of 176 patients underwent customized ICL implantation guided by ultrasound biomicroscopy (UBM) measurements of sulcus-to sulcus (STS) diameters, ciliary sulcus morphology (MCS), and anterior chamber depth (ACD). Eyes were stratified into horizontal (n=144), vertical (n=68), and oblique (n=136) groups based on implantation orientation. Postoperative assessments at 1 day, 1 week, 1 month, and 3 months included refractive outcomes, vault measurements, and rotational degree analysis using slit-lamp photography and Mediview software.

At 3 months, horizontal, vertical, and oblique groups showed comparable safety (P=0.53), efficacy (P=0.51), and vault predictability (P=0.46), with ideal vault (250–1000 μm) achieved in 92.6% of eyes. The oblique group exhibited greater rotational instability (3.88° ± 2.89°) than the vertical group (2.31° ± 1.86°, P<0.001), but was comparable to the horizontal group (3.11° ± 2.21°, P=0.14). Significant rotation primarily occurring within the first postoperative week (3.17° ± 2.06°). Oblique implantation showed a tendency to rotate toward the vertical axis but maintained acceptable stability while footplate positioning behind the ciliary processes correlated with improved rotational stability (r=−0.270, P=0.02).

UBM-guided oblique implantation of EVO ICL achieves good safety, efficacy, vault predictability and rotational stability comparable to traditional orientations, offering a viable alternative for patients with anatomically challenging or asymmetric ciliary sulcus.