Refractive and Visual Outcome of Misaligned Toric Intraocular Lens After Operative Realignment

The study was performed to evaluate the refractive and visual outcome of patients with misaligned toric intraocular lenses (IOLs) after operative realignment, with and without back-calculation of the toric axis after implantation of the IOL.

Institutional, retrospective case-control study.

This is a retrospective case series of 39 patients who underwent a second operation to realign a misaligned toric IOL from August 2013 to December 2019 at the Department of Ophthalmology, Goethe University, Frankfurt, Germany. Ideal toric axis was calculated using the back-calculator astigmatismfix.com.

The study consists of 39 treated eyes (20 [51%] right eyes). The toric IOLs showed a postoperative misalignment of 25.69 ± 26.06°. Postrotational, uncorrected distance visual acuity (UDVA) improved from 0.39 ± 0.29 logMAR to 0.27 ± 0.18 logMAR. Refractive outcome showed a reduction of residual sphere and cylinder. The postoperative UDVA when performing alignment to the preoperative calculated axis (51%) was 0.24 ± 0.16 logMAR with a cylinder of 0.90 ± 0.90 diopter (D). In the group with alignment to a back-calculated axis (49%), the UDVA was 0.32 ± 0.20 logMAR with a cylinder of 0.76 ± 0.72 D. High cylinder power IOLs (≥2 D) showed a higher decrease in residual cylinder when back-calculation was performed than low cylinder power IOLs (<2 D) (27% vs 9%). The mean spherical equivalent prediction error of the back-calculator was 0.54 ± 0.55 D.

Realignment of misaligned toric IOLs improves visual acuity and reduces residual refractive errors. Especially for high cylinder power IOLs, better refractive outcome can be seen when performing a back-calculation before realignment.