From visual acuity to spectacle independence in patients implanted with intraocular lenses

Models have been developed to predict monocular distance-corrected visual acuity (MonoCVA) from the modulation transfer function area (MTFa) measured in optical bench studies of intraocular lenses (IOLs), thereby enhancing clinicians' understanding of such studies. The present work extends these models to also predict mean binocular uncorrected visual acuity (BinoUVA) and the rate of spectacle independence (SI) in patients implanted with IOLs. Clinical outcomes were retrieved from the IOLEvidence database, selecting studies that simultaneously reported MonoCVA and BinoUVA at far, intermediate (65-67 cm), and near (40 cm) distances. These data were used to estimate BinoUVA from MonoCVA while accounting for testing distance, IOL functional classification, lens type, and postoperative spherical equivalent. Additionally, information on SI at the same distances was collected to develop a predictive model of SI based on BinoUVA. The resulting model estimates BinoUVA using the equation BinoUVA = MonoCVA -0.07+0.09⋅IFar+0.02⋅INear-0.03⋅IPRoF-N+0.06⋅SE, where SE is the spherical equivalent and IFar, INear, and IPRoF-N are binary variables representing testing conditions and IOL type. The probability of SI in patients implanted with IOLs can be predicted from BinoUVA using a logistic growth function, particularly for near-distance SI. A BinoUVA of 0.22 [95% CI: 0.21-0.24] logMAR corresponds to a 50% probability of near SI. These findings demonstrate that models originally designed to predict MonoCVA from MTFa can be extended to estimate BinoUVA and, consequently, the likelihood of spectacle independence.