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Refractive Outcomes Using Simulated Keratometry Versus Keratometry From an Optical Biometer
David L Cooke1, Karanpreet S Multani2, Jascha A Wendelstein3
1From the Great Lakes Eye Care (D.L.C.), Saint Joseph, Michigan, USA; Department of Neurology and Ophthalmology (D.L.C.), Michigan State University, College of Osteopathic Medicine, East Lansing, Michigan, USA.
The IOLMaster 700 provided more accurate refractive predictions than the Pentacam AXL for intraocular lens calculations. Standard keratometry (K) measurements from the IOLMaster 700 outperformed simulated keratometry (Sim K) from the Pentacam AXL.
Area of Science:
- Ophthalmology
- Biomedical Engineering
- Optical Science
Background:
- Accurate intraocular lens (IOL) power calculation is crucial for achieving desired refractive outcomes after cataract surgery.
- Different biometry devices and keratometry measurements can influence refractive prediction accuracy.
- Scheimpflug tomography (Simulated Keratometry - Sim K) and telecentric keratometry (Keratometry - K) are common methods for obtaining corneal power.
Purpose of the Study:
- To compare the refractive prediction accuracy of modern IOL power calculation formulas using simulated keratometry (Sim K) from a Scheimpflug tomographer versus keratometry (K) from an optical biometer.
- To evaluate the impact of different biometric data sources on IOL formula performance.
Main Methods:
- Retrospective analysis of 589 eyes undergoing cataract surgery with monofocal IOL implantation.
- Comparison of refractive prediction errors using nine IOL formulas with three biometric data sources: IOLMaster 700 (IOLM700), Pentacam AXL, and a combination.
- Assessment of accuracy using Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE).
Main Results:
- All nine formulas showed superior refractive prediction accuracy with IOLMaster 700 (IOLM700) biometry compared to Pentacam AXL biometry.
- The IOLM700 approach yielded significantly lower MAE and RMSE than the combination and Pentacam AXL approaches (P < .05).
- Formula performance varied based on the biometry source, with Cooke K6 ranking highest for IOLM700 and EVO 2.0 for Pentacam AXL and the combination.
Conclusions:
- Biometric data, including standard K from the IOLMaster 700, provides the most accurate refractive predictions for IOL power calculations.
- Simulated Keratometry (Sim K) values from the Pentacam AXL are not directly interchangeable with standard K values from SS-OCT biometers.
- The choice of biometry device and optimization significantly impacts IOL formula performance and refractive outcomes.
