Efficacy Comparison Between Toric Posterior Chamber Phakic IOL and Posterior Chamber Phakic IOL Plus Modified Steep Meridian Corneal Relaxing Incision for Moderate to High Astigmatism Corrections.

PURPOSE

To compare posterior chamber phakic intraocular lens (Implantable Collamer Lens [STAAR Surgical]) (ICL) plus modified steep meridian corneal relaxing incision (MS-CRI) to toric posterior chamber phakic intraocular lens (Toric Implantable Collamer Lens [STAAR Surgical]) (TICL) implantation for the correction of moderate to high astigmatism.

METHODS

In this prospective, randomized clinical trial, patients with myopia who had moderate to high astigmatism (200 eyes) were enrolled and divided into TICL (n = 100) and MSCRI (n = 100) groups. All patients underwent examinations for uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and subjective refraction before surgery and at the 1- and 6-month follow-up visits. Vector astigmatism analysis was evaluated using the Alpins method.

RESULTS

The mean UDVA and CDVA demonstrated significant improvement after surgery in both groups. During the 6-month follow-up, the MS-CRI group showed a slight regression tendency ( < .001) and the TICL group was stable for the astigmatism correction ( = .510). At 6 months postoperatively, the mean magnitudes of the surgically induced astigmatism were 1.46 ± 0.53 and 1.10 ± 0.48 diopters ( < .001). The correction index of the TICL group was closer to 1 compared to that of the MS-CRI group (0.95 vs 0.76). Approximately 99% of eyes in the TICL group had angle of error within ±15°, whereas 89% eyes in the MS-CRI group were within that range. A significant relationship between the magnitudes of target induced astigmatism and correction index was noted in the MS-CRI group ( < .001), but not in the TICL group ( = .592).

CONCLUSIONS

TICL implantation could achieve better visual outcomes for correcting moderate to high astigmatism compared to ICL implantation plus MS-CRI. .