Accuracy of Intraocular Lens Power Calculation in Microspherophakia Patients: Comparison of 7 Formulas
Yang Sun1,2,3, Tianhui Chen4,5,6, Zexu Chen4,5,6
1Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China, yeung_Suen@163.com.
Introduction:
The purpose of this study was to compare the accuracy of seven formulas for intraocular lens power calculation in patients with microspherophakia (MSP).
Methods:
A retrospective case series included 44 eyes from 28 patients with MSP. The mean prediction error (PE) was calculated, and the accuracy was determined by formula performance index (FPI), median absolute error (MedAE), and percentage of eyes with a PE within ±0.25 diopters (D), ±0.50 D, ±0.75 D, and ±1.00 D. Depending on whether the patients had Marfan syndrome (MFS), MSP patients 36 were sub-divided into MFS and non-MFS group.
Results:
In the non-MFS subgroup, the performance of formulas ranked by FPI from highest to lowest was BUII, Emmetropia Verifying Optical (EVO), Kane, Haigis, Sanders-Retzlaff-Kraff/Theoretical (SRK/T), Holladay 1, and Hoffer Q. In the MFS subgroup, Kane achieved the best accuracy regarding the lowest MedAE and the largest percentage of PE in the range of ±0.50 D. Similar results were obtained in eyes with shallow anterior chamber depth (ACD). In the regular ACD subgroup, the EVO provided the highest prediction accuracy and SRK/T took the second place. In the deep ACD subgroup, Holladay 1 performed superiorly presenting the lowest standard deviation values, mean absolute error and MedAE.
Conclusions:
Overall, new generation formulas showed a better trend of refractive outcomes in MSP patients. The Holladay 1 formula was suggested for eyes with deep ACD, while Haigis was not recommended.
Insights
New intraocular lens formulas show improved accuracy for microspherophakia (MSP) patients. Holladay 1 formula is recommended for deep anterior chamber depth (ACD) eyes, while Haigis is not advised.
Area of Science:
- Ophthalmology
- Biomedical Engineering
- Optics
Background:
- Microspherophakia (MSP) presents unique challenges for intraocular lens (IOL) power calculation.
- Accurate IOL power calculation is crucial for achieving optimal visual outcomes post-surgery.
Purpose of the Study:
- To compare the accuracy of seven different IOL power calculation formulas in patients diagnosed with microspherophakia (MSP).
- To identify the most suitable formulas for IOL power calculation in MSP eyes, considering variations in ocular anatomy.
Main Methods:
- A retrospective analysis of 44 eyes from 28 MSP patients was conducted.
- Formulas were evaluated based on prediction error (PE), formula performance index (FPI), median absolute error (MedAE), and the percentage of eyes within specific PE ranges.
- Patients were sub-divided into Marfan syndrome (MFS) and non-MFS groups, and also analyzed based on anterior chamber depth (ACD).
Main Results:
- In non-MFS patients, BUII and EVO formulas demonstrated superior performance.
- The Kane formula showed the best accuracy in the MFS subgroup and for eyes with shallow ACD.
- For eyes with deep ACD, the Holladay 1 formula provided the highest accuracy, indicated by the lowest MedAE and standard deviation.
Conclusions:
- Newer generation IOL calculation formulas generally offer better refractive outcomes in MSP patients.
- The Holladay 1 formula is recommended for MSP eyes with deep anterior chamber depth (ACD).
- The Haigis formula was found to be less accurate and is not recommended for this patient group.
