Axis alignment and rotational stability after implantation of the toric implantable collamer lens for myopic astigmatism.

PURPOSE: To assess axis alignment and stability of the Toric Implantable Collamer Lens (TICL; STAAR Surgical Co) over time.

METHODS

Thirty-five consecutive eyes of 19 patients received the TICL for treatment of myopic astigmatism. Manifest refraction spherical equivalent (MRSE) and manifest refractive cylinder were measured preoperatively and at 3 months postoperatively. The axis alignment of the TICL was measured using the internal OPD map obtained with the OPD-Scan II (NIDEK Co Ltd).

RESULTS

Mean refractive cylinder was reduced from 2.80+/-1.45 diopters (D) preoperatively to 0.63+/-0.75 D at 3 months postoperatively; MRSE was -7.61+/-4.02 D preoperatively and -0.14+/-0.38 D at 3 months. Mean absolute value of the measured axis misalignment from baseline (day 1) to 1 month was 2.90+/-2.11 degrees and from 1 month to 3 months was 4.6+/-11.2 degrees. Mean absolute value of the measured changes in axis misalignment from baseline to 3 months was 2.68+/-2.11 degrees (after excluding one eye that required repositioning due to TICL rotation). At 3 months postoperatively, 96.8% (30/31) eyes had <or=8 degrees and 90.3% (28/31) had <or=5 degrees of axis misalignment.

CONCLUSIONS

The TICL showed minimal axis misalignment after implantation and remained stable 3 months postoperatively.