VALIDATION OF A NEW AXIAL LENGTH CORRECTION FORMULA FOR OPTICAL BIOMETRY TO ELIMINATE ANY SYSTEMATIC ERRORS IN IOL POWER CALCULATION
Published 2026 - 30th ESCRS Winter Meeting
Reference: FP02.01 | Type: Free Paper | DOI: 10.82333/5m8r-r313
Authors: Ferdinando Cione* 1 , Isabella Pellegrino 2 , Domenico Mucci 2 , Beniamino Crescitelli 2 , Ilenia Di Paola 3 , Nicola Rosa 1
1Ophthalmological Unit, Department of Medicine, Surgery and Dentistry, Scuola Medica Salernitana,University of Salerno,Salerno,Italy;AOU San Giovanni di Dio e Ruggi D'Aragona,Salerno,Italy, 2Ophthalmological Unit, Department of Medicine, Surgery and Dentistry, Scuola Medica Salernitana,University of Salerno,Salerno,Italy, 3Department of Ophthalmology,Vimercate Hospital,Vimercate (MB),Italy
Purpose
To validate a new correction factor for axial length (ALc) measurements, recently published, to improve intraocular lens (IOL) power calculation.
Setting
University Eye Unit, Department of Medicine and Surgery, University of Salerno, Italy.
Methods
This retrospective study included patients that underwent uncomplicated cataract surgery with Tecnis PCB00 IOL implantation in the capsular bag. Preoperative evaluation consisted of a comprehensive ophthalmic evaluation, including optical biometry with IOLMaster. The Hoffer-Q, Holladay-1, SRK/T, and T2 formulas were retrospectively applied using both uncorrected AL and ALc and IOL constants from the IOL Con database. The refractive prediction errors (PE) were compared to the post operative refraction assessed at least one month after surgery. Data normality was assessed by the Kolmogorov-Smirnov test. Mean errors (ME) were tested against zero using one-sample t-tests or Wilcoxon signed-rank tests. Median absolute errors (MedAE) of the PE were also analyzed.
Results
Two hundred thirty-three eyes from 233 patients, with a mean AL of 23.54±1.42mm and mean keratometry of 44.25±1.64D were evaluated. Using uncorrected AL, the ME of PE were significantly different from zero for all formulas (p<0.001). When using ALc, the ME values approached zero across all formulas, with no statistically significant differences (p>0.05).
Conclusion
ALc is able to eliminate errors arising from optical biometry in IOL power calculation. The refractive outcomes obtained by testing this correction factor on an independent database confirm the necessity of using ALc for IOL power calculations in virgin eyes to eliminate systematic errors without the need to modify the lens constant.