Distance Acuity, Astigmatism Reduction, and Lens Rotation and Misalignment With Toric Multifocal IOLs
Purpose
To estimate the rate and degree of intraocular lens (IOL) misalignment and assess astigmatism correction and distance acuity 12 months after bilateral implantation of toric multifocal IOLs.
Methods
This study was a nonrandomized, nonmasked, parallel-group, prospective assessment of AcrySof® IQ ReSTOR® multifocal toric and nontoric IOLs (Alcon). Patients were aged ≥21 years with bilateral cataracts, preoperative best-corrected distance visual acuity (BCDVA) >0.2 logMAR, and potential acuity ≤0.2 logMAR after IOL implantation. Patients with preoperative corneal astigmatism of 0.75 D to 2.82 D in both eyes received toric IOLs (n=386); patients with astigmatism ≤0.74 D in both eyes received nontoric IOLs (n=188). Lens orientation, astigmatism reduction, binocular BCDVA, and binocular UCDVA were assessed at 12 months postimplantation.
Results
At surgery, mean ± SD toric IOL misalignment was 5.0±6.1° (first eye) and 4.7±4.0° (second eye). After 12 months, orientation change from implantation (rotation) was 1.0±6.3° (first eye) and 0.7±3.4° (second eye). The rate of rotational stability (ie, rotation <10°) was 97.6%. Five secondary surgical interventions were required because of IOL misalignment at implantation. Astigmatism was reduced by 77.1±34.0%; cylinder reduction was within 0.5 D and 1.0 D of target in 77.0% and 95.8% of eyes, respectively. Toric and nontoric IOLs achieved similar BCDVA (–0.04±0.09 vs –0.04±0.08 logMAR) and UCDVA (0.03±0.11 vs 0.02±0.10 logMAR).
Conclusion
Toric IOLs demonstrated IOL rotational stability through postimplantation month 12 and effectively reduced astigmatism in a corrective range of 0.75–2.82 D. There were no clinically relevant differences in the mean BCDVA or UCDVA between patients receiving toric or nontoric multifocal IOLs.