Posters

Evaluation of a new toric IOL optic by means of the ORA system: the effect of IOL misalignment on cylinder reduction

Poster Details

First Author: E. Mertens BELGIUM

Co Author(s):    P. Schraepen                    

Abstract Details

Purpose:

To intraoperatively compare the effect of misalignment of the Precizon and Lentis toric intraocular lenses (IOLs) on refraction by means of the ORA system and to compare postoperative outcomes.

Setting:

Medipolis, Antwerp Private Clinic, Belgium

Methods:

Prospective, randomized, comparative study in which patients with cataract and pre-existing corneal astigmatism underwent routine cataract surgery with bilateral implantation of a toric IOL model. Lens powers were calculated using the respective manufacturer’s online calculators. Emmetropia was targeted. Intraoperative refraction was measured at 10°, 5° and at 0° (mis)alignment using the Optiwave Refractive Analysis (ORA) system wavefront aberrometer (Alcon, Fort Worth, TX, USA). Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction and IOL misalignment were evaluated 1 month postoperatively. Postoperative IOL misalignment was assessed using a KR-1W Wavefront analyzer (Topcon, Tokyo, Japan).

Results:

Toric IOL implantation in 10 eyes in each subgroup resulted in an average of 1,6° rotation with the Precizon IOL and an average of 2,2° with the Lentis Toric IOL. For every degree of error in a toric IOL’s rotational misalignment, there is a 3.3 percent decrease in the correction of astigmatism. With 10 degrees misalignment, the astigmatism will be 33 percent undercorrected. This is what we found with the Lentis Toric IOL by deliberately misaligning 10° and 5°. Surprisingly we did not get the same results with the Precizon IOL. By misaligning 10° the undercorrection was on average 18% instead of the expected 33% as measured with the ORA and the average undercorrection with 5° misalignment was 9%.

Conclusions:

The new toric optic IOL Precizon gave similar results in terms of rotation one month postoperatively but performed significantly better in astigmatism correction and was less sensitive to misalignment in respect to the Lentis Toric IOL. Longer follow-up and a larger series is needed to support this findings.

Financial Disclosure:

One or more of the authors receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented