Interocular Axial Length Asymmetry and Postoperative Refractive Error After Bilateral Cataract Surgery: A Retrospective Comparative Study.

PURPOSE: To evaluate whether interocular axial length (AL) asymmetry is associated with postoperative refractive error, independent of absolute AL.

PATIENTS AND

METHODS

This retrospective comparative study included 42 patients (84 eyes) who underwent bilateral cataract surgery. Within-patient comparisons were performed between longer-AL and shorter-AL eyes, and longer-AL eyes were also compared with an AL-matched control group. Postoperative spherical equivalent (SE) at 1 month was compared with predicted SE using the Barrett Universal II and SRK/T formulas. Multivariable regression analysis was performed.

RESULTS

Mean postoperative refractive error (mean ± SD) was -0.20 ± 0.63 D in the longer-AL group vs 0.02 ± 0.50 D in the shorter-AL group (BU, p = 0.01), and -0.41 ± 0.84 D vs -0.05 ± 0.53 D (SRK/T, p = 0.02). Longer-AL eyes showed a significantly greater myopic shift than shorter-AL and control eyes. Interocular AL difference remained independently associated with postoperative refractive error.

CONCLUSION

Interocular AL asymmetry was associated with postoperative myopic shift, even after adjustment for axial length and other covariates.