Factors Predictive of Refractive Error After Toric Lens Implantation

PURPOSE: To identify factors related to suboptimal refractive outcomes after toric intraocular lens implantation. PATIENTS AND METHODS: A retrospective case-control chart review of 446 eyes with toric lens insertion by the same surgeon at a university hospital from 2016 to 2020 was conducted. Pre-operative exam findings, biometry, and one month and three month post-operative vision and refraction were noted. Reviewed charts were considered cases if uncorrected distance visual acuity (UDVA) was worse than 20/40, spherical equivalent (SE) >1 diopter (D) off target, or cylinder >1 D off target. RESULTS: Overall, 93.7% (n = 343) of eyes achieved UDVA of 20/40 or better, 92.7% (n = 306) were within 1 D of target SE, and 90.9% (n = 300) were within 1 D of target cylinder. UDVA cases had more eyes with prior LASIK (21.7% vs 7.0%, p = 0.01) and keratoconus (8.7% vs 0.6%, p < 0.001) than controls. More SE cases had prior radial keratotomy (RK) (8.3% vs 0%, p < 0.001) and keratoconus (12.5% vs 0%, p < 0.001) than controls. More cylinder cases had prior LASIK (30.0% vs 8.7%, p < 0.001) and higher mean astigmatism (2.3 vs 1.5 D, p = 0.02) than controls. More cases in all three analyses had higher toric cylinder power (T5-T9) than controls. Age, sex, eye laterality, axial length, anterior chamber depth, lens power, dry eye, anterior basement membrane dystrophy, and Fuchs’ endothelial dystrophy differences were not significant. CONCLUSION: Prior LASIK or RK, keratoconus, and higher astigmatism may increase the chance of a suboptimal outcome.