Correlation of Axial Length, Lens Thickness, and Anterior Chamber Depth in Patients Undergoing Cataract Surgery

Abstract

Background: Axial length, lens thickness and anterior chamber diameter are valuable parameters used in determining the refractive status of the eye. Aim: To determine the correlation between axial length (AL), crystalline lens thickness (LT), and preoperative anterior chamber depth (ACD) among patients undergoing cataract surgery. Patients, Materials and Methods: It was a cross‑sectional study done over a one‑year period. One hundred and fifty‑one adults with cataract in both eyes were consecutively recruited. Using an optical biometer Ultrasound A/B Scan (Chong Qing Kang Hua S&T Co., Ltd, CAS‑2000BER [Model A], China), ocular biometric data including AL, ACD, and LT were assessed for both eyes before cataract operation for either eye. Pearson’s correlation and regression analyses were applied to determine relationships between the biometric variables. Statistically, significance was taken as P < 0.05. Results: One hundred and fifty‑one (302 eyes) adult participants were studied, consisting of 77 (51.0%) males and 74 (49.0%) females. The age range was 12–88 years, with a mean age of 57.73 ± 14.87 years (95% confidence interval, 54.70–59.90). Correlation analysis revealed that AL and ACD were positively correlated (r = 0.164, P = 0.002). AL and LT demonstrated a statistically insignificant and very weak positive correlation (r = 0.071, P= 0.217). ACD was negatively correlated with LT(r = −0.375, P= 0.000). On multiple regression, AL(z‑score = 0.191) and LT (z‑score = −0.387) were significant predictor estimates of the regression model for ACD (P = 0.000); a hypothetical equation for ACD was generated: ACD_predicted = 2.978 + (−0.522 × LT in mm) + (0.106 × AL in mm). Conclusion: LT is an important biometric parameter that should be considered, along with other biometric parameters, in determining effective lens position in patients undergoing cataract surgery. The narrowing of ACD with age is largely due to increasing LT. Using an optical biometer, ACD is predominantly influenced by LT than the AL.