Functional Classification Of Intraocular Lenses Based On Defocus Curve Meta-Analysis: Toward A Quantitative Model For Functional Vision

To develop a quantitative, data-driven functional classification of presbyopia-correcting intraocular lenses (IOLs) using range-based mean logMAR visual acuity derived from defocus curves, and to explore study-level modifiers and their relationship with spectacle independence. IOL selection remains challenging due to inconsistent performance classifications. A defocus curve–based framework provides a clinically meaningful basis for comparing functional visual outcomes.

Systematic review and meta-analysis of published studies, conducted according to PRISMA 2020. The study protocol was prospectively submitted to the International Prospective Register of Systematic Reviews (PROSPERO) and is available under the registration number CRD420250649198. PubMed was searched through June 2025.

Eligible studies included pseudophakic adults implanted with commercially available IOLs and reporting defocus curves. Defocus-curve values were extracted from tables or digitized from figures, then averaged within predefined ranges of focus (RoFs). Separate random-effects meta-analyses were performed for each IOL model and RoF. Meta-regressions assessed the influence of testing modality (binocular vs monocular), refractive target, and toric IOL use. Latent class analysis (LCA) was used to identify functional IOL groups based on range-based logMAR means. Associations between logMAR values and patient-reported outcomes were examined through multilevel meta-regression when data were available.

A total of 70 studies (175 study arms) were included. Substantial heterogeneity was observed across IOL models and RoFs. Monocular testing and myopic targets were associated with small but significant worsening of visual acuity, while toric IOL use had small beneficial effects. LCA identified four functional classes, ranging from optimal performance across all RoFs (C1) to distance-only profiles (C4). Across RoFs, 35/63 IOLs performed better than 0.2 logMAR at FAR, 37/63 at INTERMEDIATE, and 33/63 at NEAR. Near logMAR values were significantly associated with spectacle independence and, to a lesser extent, satisfaction. No consistent association was found with dysphotopsias.