Accuracy of 8 Modern Intraocular Lens Power Calculation Formulas in Asian Eyes With Axial Length ≥ 32.00 mm

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Clinical Optics

Background:

• Accurate intraocular lens (IOL) power calculation is crucial for achieving optimal visual outcomes after cataract surgery.
• Eyes with long axial lengths (AL) present unique challenges for IOL power calculation formulas.
• Evaluating modern IOL formulas in specific populations, such as Asian eyes with AL ≥ 32.00 mm, is essential for refining surgical planning.

Purpose of the Study:

• To compare the predictive accuracy of eight contemporary IOL power calculation formulas.
• To identify the most reliable formulas for Asian eyes with AL ≥ 32.00 mm.

Main Methods:

• A retrospective observational study included 330 Asian cataract patients with AL ≥ 32.00 mm.
• Eight IOL formulas (Barrett Universal II, Cooke K6, EVO 2.0, Hill-RBF 3.0, Kane, Pearl-DGS, Hoffer QST, and Zhu-Lu) were evaluated.
• Prediction error (PE) was analyzed, with formulas adjusted for mean PE bias. Outcomes were stratified into Main (32.00 mm ≤ AL < 35.00 mm) and Ultra-Long (AL ≥ 35.00 mm) groups.

Main Results:

• In the Main Group, Zhu-Lu and Cooke K6 showed the lowest root mean square absolute error (RMSAE).
• Cooke K6, EVO 2.0, and Pearl-DGS demonstrated the lowest median absolute error (MedAE).
• Pearl-DGS and Zhu-Lu had the highest proportions of eyes within ±0.50 D and ±1.00 D prediction error, respectively. Hoffer QST performed poorly in all metrics.

Conclusions:

• Modern IOL formulas exhibit varying predictive accuracy in long eyes (AL ≥ 32.00 mm).
• Cooke K6, EVO 2.0, Pearl-DGS, and Zhu-Lu are recommended for this patient cohort.
• Formula selection may depend on specific accuracy metrics prioritized for clinical use.