Purpose:

To describe the differences in predicted lens position (Olsen C constant) vs. measured actual lens position post-operatively in patients who underwent cataract surgery and implantation of a monofocal intraocular lens.

Methods:

Adult subjects in need of cataract surgery with implantation of a monofocal IOL were recruited to participate. Subjects who satisfied the study eligibility criteria completed cataract extraction surgery and were implanted with an ACRYSOF IQ Monofocal IOL, Model SN60WF in 1 or both eyes. IOL SRK/T A-constant estimated based on the preoperative biometry, IOL power and postoperative manifest spherical equivalent refraction at 3 months follow up. Predicted Lens position using the Olsen C constant pre-operatively was compared to the measured lens position postoperatively. All subjects were follow up for up to 3 months

Results:

A total of 162 subjects were enrolled into the study, 150 subjects were successfully implanted with the monofocal IOL and 148 completed the study. At 3 months, the overall the mean difference between predicted and measured lens position was 0.021 +/- 0.189 mm, 90 % confidence interval range of -0.010 to 0.052. Individual mean C values were similar between the 3 sites namely, 0.378 (site 1), 0.320 (Site 2) and 0.391 (Site 3).

Conclusions:

Across all sites in the study, the lens position predicted by Olsen’s formula was in good agreement with the actual lens position measured clinically at the 3-month postoperative visit.