Refractive predictive errors using Barrett II, Hoffer-Q, and SRKT formulae for pediatric IOL implantation

Area of Science:

• Ophthalmology
• Pediatric Ophthalmology
• Biomedical Engineering

Background:

• Accurate intraocular lens (IOL) power calculation is crucial for visual outcomes in pediatric patients undergoing lensectomy.
• Existing IOL calculation formulas may have varying accuracy in the unique biometric environment of a developing pediatric eye.

Purpose of the Study:

• To compare the refractive prediction accuracy of three common IOL calculation formulas: Barrett II universal (BU II), Hoffer-Q, and SRKT.
• To evaluate formula performance across different pediatric subgroups based on age, axial length, and keratometry.

Main Methods:

• Retrospective analysis of 151 eyes from 104 children who had lensectomy and IOL implantation between 2015 and 2023.
• Comparison of mean prediction error (PE) and absolute PE < 1.0 D for BU II, Hoffer-Q, and SRKT formulas.
• Subgroup analysis based on axial length (<22 mm vs. ≥22 mm), age at surgery (≥24 months vs. younger), and mean keratometry (≥44.5 D).

Main Results:

• The Barrett II universal (BU II) formula demonstrated a low mean prediction error (-0.08 ± 1.54 D).
• BU II showed a smaller prediction error than SRKT in eyes with axial length < 22 mm and a smaller error than Hoffer-Q in eyes with axial length ≥ 22 mm.
• BU II achieved an absolute prediction error < 1.0 D in 66% of eyes, significantly higher than SRKT (35%).

Conclusions:

• The Barrett II universal (BU II) formula is a reliable and stable option for pediatric IOL calculations.
• BU II exhibits consistent accuracy across a range of pediatric biometric parameters, including varying axial lengths, keratometry readings, and patient ages.
• The formula's stability makes it suitable for the dynamic changes in the pediatric eye during growth.