Refractive outcomes during transition from ultrasound to optical biometry in cataract surgery: a real-world study from a resource-limited setting

Clinical Relevance Accurate intraocular lens power calculation is a key determinant of postoperative refractive outcomes and patient satisfaction after cataract surgery. Reliable biometric measurements remain essential for achieving optimal visual outcomes across diverse clinical settings.Background To evaluate refractive outcomes during transition from ultrasound-based to optical biometry-guided cataract surgery in a resource-limited secondary referral centre and to identify factors associated with refractive prediction accuracy.Methods This retrospective observational study included 444 eyes undergoing uncomplicated phacoemulsification cataract surgery. Ultrasound biometry was performed using contact applanation technique before optical biometry became available in institutional practice. Absolute prediction error (APE), signed prediction error, refractive benchmark outcomes and factors associated with refractive accuracy were analysed.Results The mean APE was significantly lower in the optical biometry group compared with the ultrasound biometry group (0.34 ± 0.33 D vs 0.65 ± 0.60 D, p < 0.001). A significantly greater proportion of eyes measured with optical biometry achieved refractive outcomes within ±0.25 D, ±0.50 D, ±0.75 D, and ±1.00 D of the target refraction than eyes measured with ultrasound biometry (all p < 0.01). Signed prediction error analysis demonstrated a mild myopic shift in the ultrasound biometry group (−0.14 ± 0.88 D vs 0.10 ± 0.47 D, p = 0.029). Multiple regression analysis identified biometry method and preoperative corneal astigmatism as independent predictors of refractive prediction error.Conclusions In this real-world study from a resource-limited clinical setting, eyes measured with optical biometry demonstrated lower prediction errors and higher refractive accuracy than eyes measured with ultrasound biometry. However, given the retrospective and non-contemporaneous nature of the study groups, these findings should be interpreted as an association rather than definitive evidence of superiority. Higher preoperative corneal astigmatism was independently associated with reduced refractive accuracy.