Type of publication:
Conference abstract
Author(s):
Nayak D.; Iqbal N.; Makwana T.; Sathiaraj S.; Olagunju A.; Yadav S.
Citation:
Eye (Basingstoke). Conference: The Royal College of Ophthalmologists Annual Congress 2025. Liverpool United Kingdom. 39 (pp 208-209), 2025. Date of Publication: 01 Jun 2025.
Abstract:
Introduction: To evaluate the accuracy of IOL power determination using new generation super formulas in IOL-cal.com in comparison to traditional formulas such as SRK/T, Hoffer Q, and Holladay 1 for cataract surgery patients, particularly those with challenging biometric characteristics to optimise visual outcome. Method(s): Study Design: Prospective study involving 100 patients undergoing cataract surgery. Preoperative Measurements: Axial length (AL) measured using optical biometry. Corneal curvature (K) measured using keratometry or corneal topography. Anterior chamber depth (ACD) measured to assess proper IOL power. IOL Power Calculation: IOL-cal.com: Integrated tool using multiple formulas (Ladas/ Kane, SRK/T, Hoffer Q, Holladay 1) based on patient-specific measurements. Traditional formulas for comparison: SRK/T, Hoffer Q, and Holladay 1. Surgical Procedure: Phacoemulsification with monofocal IOL implantation in the capsular bag. Primary Outcome Measure: Mean Absolute Prediction Error (MAE) of postoperative refractive outcomes at 6 weeks. Secondary Outcome Measures: Proportion of patients achieving postoperative refraction within +/-0.5 D of target refraction. Rate of residual astigmatism at 6 weeks post-surgery. Statistical Analysis: Descriptive statistics, paired t-tests or ANOVA, chi-square tests for categorical variables, significance set at p < 0.05. Result(s): Mean Absolute Prediction Error (MAE): IOL-cal.com demonstrated a significantly lower**Mean Absolute Prediction Error (MAE)**when compared to traditional IOL power calculation formulas, with a p-value < 0.05. This indicates that IOL-cal.com provided more accurate predictions of postoperative refractive outcomes. The tool particularly excelled in predicting refractive outcomes for patients with**short eyes**(<22 mm) and**long eyes**(>26 mm), showing improved precision in both these challenging biometric categories. Refractive Outcomes: A higher percentage of patients in the IOL-cal.com group achieved a refractive outcome within +/-0.5 dioptres (D) of the target refraction (82%) compared to the traditional formula group. The percentage of patients achieving this target refraction was 75% for the SRK/T formula, 71% for the HofferQ formula, and 73% for the Holladay 1 formula. These results suggest that IOL-cal.com is more effective at helping patients achieve a closer match to their target refractive outcome. Residual Astigmatism: The incidence of significant residual astigmatism (greater than 0.75 D) was lower in the IOL-cal.com group, with only 12% of patients showing significant astigmatism after surgery. In contrast, the SRK/T formula showed a residual astigmatism rate of 18%, the Hoffer Q formula had a rate of 20%, and the Holladay 1 formula had a residual astigmatism rate of 19%. These findings indicate that IOL-cal.com was more effective in minimizing postoperative astigmatism, particularly in comparison to traditional formulas. Conclusion(s): The use of IOL-cal.com for intraocular lens (IOL) power determination offers significant advantages over traditional formulas like SRK/T, Hoffer Q, and Holladay 1 by providing more accurate and consistent results. This online tool integrates multiple advanced IOL power calculation formulas and tailors them to individual biometric parameters, such as axial length, corneal curvature, and anterior chamber depth. By adjusting for these factors, IOL-cal.com enhances the likelihood of achieving a refractive outcome that closely matches the target refraction, significantly reducing the Mean Absolute Prediction Error (MAE) and minimizing residual astigmatism after cataract surgery. IOL-cal.com proves especially useful in challenging cases, such as patients with extreme axial lengths, irregular corneal curvature, or those who have previously undergone refractive surgery. These situations often complicate traditional IOL power calculations, but IOLcal.com's ability to account for such complexities ensures more precise outcomes. Its user-friendly interface, combined with its ability to integrate multiple formulas, makes it a highly valuable tool for cataract surgeons. The tool's enhanced accuracy and ability to improve refractive outcomes position it as an essential resource for optimizing cataract surgery, particularly for complex or high-risk cases.
DOI: 10.1038/s41433-025-03831-0
