Investigating the impact of residual refraction within ±1.0 dioptre on uncorrected distance visual acuity in pseudophakic eyes: a cross-sectional study.

Abstract

To investigate the impact of residual refraction within ±1.0 dioptre (D) on uncorrected distance visual acuity (UDVA) in pseudophakic eyes. Cross-sectional study. This study was based on retrospectively collected electronic refraction records from a tertiary care academic ophthalmology centre in southern China between May 2022 and July 2025. Patients aged ≥40 years who underwent uneventful phacoemulsification cataract surgery with in-the-bag monofocal intraocular lens implantation and achieved a postoperative corrected distance visual acuity (CDVA) of ≤0.1 logarithm of the minimum angle of resolution were enrolled. They were stratified by astigmatism subtypes: minimal astigmatism (<0.50 D), with-the-rule (WTR) astigmatism, against-the-rule (ATR) astigmatism and oblique astigmatism. Postoperative evaluation (≥1 month) included spherical equivalent (SE) refraction, UDVA and CDVA. UDVA was compared across eyes with SE intervals of 0.50 D within ±1.0 D. ORs were calculated to assess the relative risk of failing to achieve a UDVA of 0.1 or better for postoperative SE within ±1.0 D, using 0.00 D as the reference. The study included 1333 eyes from 1333 patients (mean (SD) age, 66.1 (8.96) years; 532 male (39.9%)). Overall, and particularly in the minimal astigmatism (<0.50 D), ATR astigmatism and oblique astigmatism subgroups, hyperopic eyes exhibited significantly better UDVA than their myopic counterparts. Slight myopia [-0.50 D, 0 D) significantly worsened UDVA versus 0 D in both the overall population and the minimal astigmatism subgroup. Slight hyperopia (0 D, +0.50 D] minimally affected UDVA, whereas an equivalent degree of myopia increased the odds of not achieving UDVA ≤0.1 by 1.55-fold (95% CI 1.08 to 2.21) overall and by 3.14-fold (95% CI 1.49 to 6.58) in the minimal astigmatism subgroup. Additionally, UDVA was optimal with minimal astigmatism and decreased progressively with each 0.50 D increment in residual astigmatism magnitude, a dose-dependent trend consistent across astigmatism subtypes. The impact of refractive errors (≤1.0 D) on UDVA was associated with the magnitude and type of astigmatism. Residual astigmatism of ≥0.50 D exerted a significant negative effect on UDVA. A plano SE (0 D) was optimal for minimum and WTR astigmatism, whereas slight hyperopia yielded superior UDVA in ATR and oblique astigmatism.