Comparison of Optical Biometric Parameters Between Phakic and Pseudophakic Eyes: A Retrospective Clinical Study

Background and Objective: To evaluate the effect of pseudophakia on anterior chamber depth and other ocular biometric parameters, and to analyze its relationship with age, sex, and axial length. Materials and Methods: Optical biometry data from 2372 eyes of 1186 patients-each with one pseudophakic and one phakic eye-were retrospectively analyzed using the Lenstar LS 900^®. Recorded parameters included axial length (AL), central corneal thickness (CCT), aqueous depth (AD), anterior chamber depth (ACD), lens thickness (LT), keratometry values, and white-to-white distance (WTW). Interocular differences and correlations among variables were statistically assessed. Results: The mean age was 62.8 ± 16.0 years (range, 11-92), and 57.1% were male. Compared with phakic eyes, pseudophakic eyes showed significantly lower AL, WTW, and K1 values (p < 0.01, p < 0.001) and higher CCT, AD, ACD, and astigmatism (AST) values (p < 0.001). No significant difference was observed in K2 (p > 0.05). In both phakic and pseudophakic eyes, males had higher AL, AD, WTW, and ACD and lower K1 and K2 values than females (p < 0.001, p < 0.05). Increasing age was associated with decreased AL and CCT. In phakic eyes, ACD and AD were negatively correlated with age, whereas in pseudophakic eyes, the correlation was positive. Conclusions: Cataract surgery and intraocular lens implantation significantly alter anterior segment structures. Pseudophakia mainly affects ACD and AD, which may be related to postoperative intraocular pressure reduction and may improve the precision of IOL power calculations.