Objective:

To outline the evolution of IOL power calculation formulas and provide a personalized selection strategy based on axial length, emphasizing the importance of tailored approaches for different patient profiles.

Key Findings:

• First- and second-generation formulas have poor predictive performance in extreme axial lengths, leading to suboptimal surgical outcomes.
• Third-generation formulas improve accuracy by incorporating effective lens position calculations, making them more reliable for standard cases.
• Fourth-generation formulas enhance stability by integrating additional biometric parameters, which is crucial for atypical eyes.
• New-generation formulas utilize machine learning for exceptional accuracy across various eye types, particularly in complex cases.

Interpretation:

A single IOL formula cannot meet the diverse needs of eyes with complex anatomical variations, necessitating a personalized selection approach based on axial length to ensure optimal surgical outcomes.

Limitations:

• No absolute gold standard exists for IOL power calculation formulas, which complicates clinical decision-making.
• Further validation is required for newer formulas like the Zhu-Lu formula to establish their reliability in practice.

Conclusion:

Future studies are needed to improve the accuracy of IOL power calculation and assist in clinical selection, particularly focusing on the validation of new formulas and their application in diverse patient populations.