Comparison of long-term surgical outcomes for scleral-fixated versus retropupillary iris-claw intraocular lens

Background To compare the clinical features and long-term treatment outcomes of patients undergoing secondary intraocular lens (IOL) surgery with scleral-fixated (SFIOL) versus retropupillary iris-claw IOL (RPICIOL). Methods Consecutive patients treated between June 2014 and December 2019 at two tertiary centres were retrospectively reviewed. The primary outcome was the best-corrected visual acuity (BCVA). Secondary outcomes included factors associated with significant corneal endothelial injury and postoperative redislocation. Results This study included 395 eyes undergoing surgery with SFIOL (237 eyes, 60%) or RPICIOL (158 eyes, 40%), with no differences in baseline BCVA (p = 0.76) or endothelial cell density (ECD) (p = 0.39). Compared with the SFIOL group, the RPICIOL group had faster visual recovery (postoperative month 1, 20/37 vs. 20/46, p = 0.005) sustained to over 36 months (p = 0.034), favourable absolute prediction errors (within 0.5D, 67.3% vs. 54.9%, p = 0.027), and shorter operation times (52.7 vs. 60.9 min, p = 0.015). There was no difference in ECD after 12 months (P = 0.282). Over a mean follow-up duration of 33 months (152 cases >3 years, 38.5%), the SFIOL group experienced more cases of tilted/decentred IOLs (14 vs. 1, p = 0.006), suture exposure (7 vs. 0, p = 0.045), and redislocation (17.7% vs. 10.1%, p < 0.001). Multivariable regression showed that a final BCVA below 20/40 was associated with SFIOL (P = 0.007), older age (p = 0.001), intraoperative complications (p = 0.002), past history of vitrectomy/glaucoma surgery or uveitis (p = 0.046), and surgically induced astigmatism >1D (p = 0.029). Conclusions RPICIOL appears to be a safe and effective surgical option for secondary IOL surgery over a long-term follow-up, comparing favourably against conventional SFIOL.