Relationship of Angle Kappa with Ocular Parameters using Swept-Source Ocular Coherence Tomography in Cataract Surgery Patients.

Abstract

Purpose: To assess the relationship between angle kappa (apparent chord mu) and ocular parameters in cataract patients.

Methods: In this cross-sectional study, the data on apparent chord mu, age, axial length, anterior chamber depth, anterior and posterior mean keratometry, mean total keratometry, white-to-white, central corneal thickness and lens thickness were collected for consecutive cataract patients. Correlation (Pearson) between chord mu and the other ocular parameters was calculated. A stepwise backward multiple regression analysis was performed to identify the combination of ocular parameters strongly correlating to chord mu.

Results: Two thousand four hundred and sixty-four eyes (1232 patients) were included in this study. The mean age was 72.7 ± 12.7 years (18-97 years). Univariate analysis showed a significant positive correlation of chord mu to age (R = 0.06, p = .01), lens thickness (R = 0.12, p < .01), mean keratometry (R = 0.08, p < .01), and mean total keratometry (R = 0.08, p < .01). Whereas there was a significant negative correlation with white-to-white (R = -0.04, p = .03), axial length (R = -0.19, p < .01), and anterior chamber depth (R = -0.2, p < .01). Male gender (R = -0.04, p = .05) and central corneal thickness (R = 0.04, p = .06) were not significantly correlated. Multivariate stepwise backward regression analysis showed a combination of four factors (female sex, reduced axial length and anterior chamber depth and steep mean keratometry) significantly related to chord mu (angle kappa).

Conclusion: Female gender, reduced axial length and anterior chamber depth, and higher mean keratometry correlate to apparent chord mu (angle kappa) in cataract patients. These findings can help identify vulnerable patients who can have appropriate counseling on the prognosis of postoperative optical and visual outcomes.