Results of a toric aspheric IOL with 'markerless“ implantation in cataract surgery

Session Details

Session Title: Toric IOLs

Session Date/Time: Sunday 14/09/2014 | 16:30-18:30

Paper Time: 17:57

Venue: Capital Hall B

First Author: : C.Mielke GERMANY

Co Author(s): :    P. Hoffmann   C. Ritter           

Abstract Details

Purpose:

To assess astigmatic and refractive outcome with markerless implantation of a toric aspheric IOL and their stability.

Setting:

Eye surgery centre “eyelight”, Berlin, Germany

Methods:

Retrospective analysis of 120 consecutive operated eyes of 92 patients with cataract surgery and toric IOL implant with Acrysof toric IOL (T2 up to T8) in a period of one year (December 2012 through December 2013). All Patients had a corneal astigmatism of 1 dpt or higher. Corneal astigmatism was measured and IOL calculated with Haag-Streit Lenstar, Nidek AL-Scan, Oculus Pentacam HR. Keratometry was evaluated as indicated by the device as well as corrected by vector addition of -0.25 D x 90° (= presumed posterior astigmatism). In all patients uncomplicated cataract surgery with intraoperativly markerless alignment of the toric IOL using the eyetracker of SMI /Alcon Verion was done by one surgeon. Preoperative data (high and axis of corneal cylinder, corneal topography) and postoperative data (axis of IOL alignment, measured with dilated pupil on slit lamp and with Nidek OPD toric IOL programme) were taken. Postoperative spherical equivalent and refractive cylinder were evaluated at day 1 and 3 to 12 month postoperatively. To quantify the predictive precision of diagnostics, the cylindrical prediction error (CPE, difference vector between postop. manifest cylinder and predicted cylinder) was calculated.

Results:

Mean pre-operative corneal astigmatism was 1.83 dpt (1-5.25). Mean refractive cylinder at day 1 postoperatively was 0.059 dpt (0-1.25) and 0.086 dpt (0-1.25) at month 3 to 12 respectively. The difference in between 1 day and 3-12 months postoperatively was not statistically significant (p=0.158). Mean absolute misalignment of the t-IOL between aimed and measured axis postoperatively was 3.5 degree (n=120). In the majority of patients the mean deviation was within 1.67 degrees, but in 2 patients absolute misalignment of axis was greater than 30 degrees. The mean deviation of postoperative and target spherical equivalent refraction was 0.249 dpt (0-1.5) at day 1 and 0.258 dpt (0-1.5) at 3 to 12 months. No statistical significant change (p=0.105) of postoperative spherical equivalent was observed in follow up. CPE was 0.54 D for Lenstar, 0.49 D for Lenstar corrected, 0.61 D for AL-Scan, 0.61 D for AL-Scan corrected, 0.64 D for Pentacam, 0.61 D for SMI and 0.44 D for the median of all 6 measurements.

Conclusions:

Implantation of toric intraocular lenses with markerless alignment is an effective, safe and predictable method to manage corneal astigmatism in patients undergoing routine cataract surgery. Preoperative diagnostics are of utmost importance for the result. Careful weighting of several measuring results can distinctly improve the refractive outcome. Astigmatism neutral incisions and SMI aided positioning of the toric IOL ensure precise prediction of residual cylindrical refraction.

Financial Interest:

NONE