Efficacy comparison of moderate to severe astigmatism: implantable collamer lens combined with paired opposite clear corneal incisions versus toric implantable collamer lens.

PURPOSE: To compare the efficacy of Implantable Collamer Lens (ICL) combined with paired opposite clear corneal incisions (OCCI) versus Toric Implantable Collamer Lens (TICL) for moderate to severe astigmatism.

METHODS

This retrospective comparative study included 40 patients with moderate to severe astigmatism (cylinder 1·5D-3·0D). Based on patient preference, 20 eyes underwent TICL implantation (TICL group) and 20 eyes underwent ICL with OCCI (OCCI group). Preoperative and 6-month postoperative data were analyzed, including uncorrected and corrected distance visual acuity (UDVA, CDVA), refraction, higher-order aberrations (HOAs), and Alpins vector parameters (target-induced astigmatism [TIA], surgically induced astigmatism [SIA], difference vector [DV], correction index [CI], angle of error [AE]).

RESULTS

At 6 months postoperatively, both groups showed significant visual improvement. The proportion achieving UDVA ≥ 20/20 was 100% in TICL group and 95% in OCCI group. Residual astigmatism ≤ 1·0D was achieved in 95% (TICL) and 90% (OCCI). Spherical equivalent within ±1·0D was 95% and 90%, respectively. OCCI induced significantly more HOAs, horizontal coma, and horizontal trefoil postoperatively compared to TICL (all p < 0.05). Vector analysis showed no significant between-group differences in TIA, SIA, DV, CI, or AE (all p > 0.05).

CONCLUSIONS

ICL combined with OCCI yields acceptable visual and refractive outcomes for moderate to severe astigmatism, though slightly inferior to TICL in accuracy and HOAs. It represents a viable alternative when TICL is unavailable or contraindicated.