• anterior chamber depth;
  • intraocular lens;
  • intraocular lens stability;
  • optic tilt;
  • phacoemulsification;
  • ultrasound biomicroscopy


Purpose:  To assess the postoperative stability of three-piece intraocular lens (IOL) implants using ultrasound biomicroscopy (UBM).

Methods:  This is a prospective observational cohort case series. Best-corrected visual acuity (BCVA) assessment, slit lamp examination, refraction and UBM evaluation were performed preoperatively and at 1, 6, 12, 18 and 24 months postoperatively. The anterior chamber depth (ACD) and IOL tilt angles at the 12, 6, 3 and 9 o’clock meridians were assessed.

Results:  Twenty-one consecutive adult patients (21 study eyes) were recruited, but two dropped out from the study. The average age during cataract surgery was 71.7 years (60–83, SD 6.0). There were very slight changes in the refraction and IOL stability characteristics at all the postoperative follow-up time points. These were not found to be statistically significant, apart from the increase in ACD from months one (3.85 ± SD 0.29) to six (3.91 ± SD 0.26) (p = 0.01, paired t-test).

Conclusion:  There was a small but statistically significant increase in ACD between the first and sixth postoperative month, but ACD remained stable thereafter. This was not associated with any significant changes in refraction or BCVA. In contrast, IOL optic tilt remained statistically unchanged throughout the 24-month study duration.