Crystalline Lens Equatorial Plane: A Novel Ss-Oct Biometry Parameter For Predicting Postoperative Intraocular Lens Position

To evaluate whether the equatorial lens plane (EQ), estimated using SS-OCT biometry and custom-made software, enhances the prediction of intraocular lens (IOL) position after cataract surgery compared to state-of-the-art methods.

Department of Opthalmology, General University Hospital of Elche (Spain)

A prospective consecutive cohort study was conducted on patients undergoing cataract surgery with phacoemulsification and IOL implantation. Preoperative biometry was performed using Anterion®. The EQ plane was defined as the distance between the corneal epithelium and the line connecting the intersection points of the anterior and posterior lens curvatures. A semi-automatic custom Python 3 software was used to detect lens surfaces and calculate this parameter. Postoperative biometry was performed to measure IOL position. Multilinear regressions with various biometric variables were computed. Adjusted R-squared, Root Mean Squared Error (RMSE) and Mean Absolute Error (MAE) were calculated for each model and ANOVA was used compare models.

180 eyes from 180 different patients were included. A strong correlation was found between the preoperative estimated EQ plane and measured postoperative IOL position (Pearson Coefficient = 0.7966 (p-value < 0.0001). The univariate regression with EQ showed a statistically significant improvement compared to the multivariate regression model including "Anterior Chamber Depth (ACD) + Lens Thickness (LT) + White to White (WTW)" (F-value = 9.88; p = 0.000005). Adding EQ to "ACD + LT + WTW" resulted in an increse in adjusted R2 (0.628 vs 0.685), and a reduction in MAE 0.120 vs 0.108) and RMSE values (0.151 vs 0.138).

A strong correlation was found between the preoperative estimated equatorial lens plane and the measured postoperative IOL position. Simple regression with EQ was significantly more accurate than multivariate regression models using traditional biometric parameters such as "ACD + LT + WTW" for predicting postoperative IOL position. The addition of EQ resulted in a substantial reduction in the sum of squared residuals and improved the overall model fit. These results suggest that the equatorial lens plane could be a valuable parameter for enhancing the refractive outcomes of cataract surgery.