Toric Implantable Collamer Lens Implantation Combined With Steep Meridian Corneal Incision For Astigmatism Over Six Diopters Using A Digital-Assisted Reference Marking System

To evaluate the effectiveness of toric implantable collamer lens (TICL) implantation combined with steep meridian corneal incision for astigmatism over 6 diopters (D) using a digital-assisted reference marking system (Callisto Eye system).

Onnuri Smile Eye Clinic, Seoul, South Korea

This retrospective study analyzed patients who underwent TICL (Staar Surgical) implantation either after or concurrently with a steep meridian corneal incision (SMCI) to correct astigmatism greater than 6 D. The Callisto Eye image-guided system was used for both corneal incision and TICL alignment. Clinical outcomes were evaluated at 6 months postoperatively.

A total of 31 eyes from 21 patients were included. The mean preoperative astigmatism was -7.22 ± 1.03 D (range, -10.0 to -6.25 D). At 6 months postoperatively, mean uncorrected distance visual acuity was 0.02 ± 0.08 logMAR (range, −0.08 to 0.30). The mean residual astigmatism was -1.34 ± 0.86 D (range, -3.75 to -0.25 D), with 55% of eyes within 1.0 D. The mean surgically induced astigmatism was 6.82 ± 0.92 D. Vector analysis demonstrated a tendency toward undercorrection with increasing preoperative astigmatism. Postoperative lens rotation requiring TICL repositioning occurred in two eyes, and one eye underwent lens exchange due to astigmatic overcorrection.

TICL implantation combined with SMCI using a digital-assisted reference marking system provided favorable visual and refractive outcomes in eyes with astigmatism exceeding 6 D. However, a tendency toward astigmatic undercorrection, particularly in eyes with higher preoperative cylinder, should be carefully considered during surgical planning.