The effect of intraocular lens tilt on visual outcomes in scleral-fixated intraocular lens implantation

Purpose To investigate the effect of scleral-fixated intraocular lens (IOL) tilt on visual outcomes. Methods Ninety-four eyes of consecutive 94 patients who underwent scleral-fixated IOL implantation with Z-suture technique were included in this prospective study. The values of pre- and postoperative 12th month uncorrected visual acuity (UCVA), cylindrical refractive error, best-corrected visual acuity (BCVA) and corneal and lenticular astigmatism were recorded. The position of the implanted IOL was evaluated with anterior segment optical coherence tomography (AS-OCT). The relationships between the AS-OCT measurements and the visual acuity or refractive errors were investigated. Results The IOL position was evaluated as tilted in 68 (72.3%) patients: 29 (30.8%) in both vertical + horizontal axes, 30 (31.9%) in the horizontal axis and 9 (9.6%) in the vertical axis. There were no significant differences between patients with and without tilt IOL position in terms of the UCVA, BCVA, cylindrical refractive error and lenticular astigmatism (p > 0.05, for each). The mean BCVA was significantly higher in the no-tilt group than in the both horizontal + vertical tilt and the vertical tilt groups (p = 0.03, p = 0.04, respectively). The mean lenticular astigmatism was significantly higher in the vertical tilt group than the other groups (p = 0.04). Conclusion Tilting in IOL position occurs commonly; however, IOLs with tilting on any of the axes do not have significantly worse outcomes when compared with IOLs with no tilt, in terms of visual results and refractive errors. On the other hand, tilting on the vertical axis is observed less commonly, yet is more effective on visual results and refractive errors, when compared with tilting on the horizontal axis.