Role of changes in lens position and corneal curvature in long-term refractive shift after cataract surgery

Session Details

Session Title: Cataract Surgery Outcomes. IOL Power Calculations

Session Date/Time: Monday 07/09/2015 | 16:30-18:30

Paper Time: 17:16

Venue: Room 1

First Author: : S.Klijn THE NETHERLANDS

Co Author(s): :    V. Sicam   N. Reus                 

Abstract Details

Purpose:

To assess the contribution of intraocular lens (IOL) position shift and corneal curvature change in long-term refractive shift after cataract surgery.

Setting:

Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands.

Methods:

Fifty-nine eyes of 59 patients who underwent routine cataract extraction with implantation of a hydrophobic acrylic single-piece IOL (Acrysof SA60AT, Alcon) in the capsular bag were enrolled. Refractive shift between 1 month and 1 year postoperatively was measured with the ARK-530A autorefractor (Nidek). Changes in IOL position and corneal curvature during the same time interval were measured with the Lenstar LS-900 biometer (Haag-Streit), and a Gaussian optics-based thin lens formula was used to calculate the refractive effect of these changes. The correlation between the measured and calculated refractive shift was assessed.

Results:

A statistically significant average posterior shift of the IOL of 0.033 ± 0.060 mm was observed (P<0.01). This led to a median calculated absolute refractive effect of 0.05 D, which did not correlate with the measured refractive shift (Pearson's r=0.10, P=0.46). A median calculated absolute refractive effect of 0.17 D resulted from natural fluctuations in corneal curvature, and this correlated well with the measured refractive shift (Pearson's r=0.55, P<0.001).

Conclusions:

Long-term follow-up of pseudophakic eyes may reveal a shift of the IOL position, but the refractive effect of natural fluctuations in corneal curvature in these eyes is more than three times as high. Similar fluctuations in corneal curvature have been measured by others in phakic eyes. Thus, subtle long-term axial shifting of the IOL cannot be anticipated in the planning of cataract surgery.

Financial Interest:

NONE