Belgrade 2018 Meeting Highlights Registration Abstract Submission Exhibition Virtual Exhibition Hotel Information Satellite Programme Visa Letter Application

Ray tracing based simulations of toric intraocular lens power calculation for regular and irregular corneas

Search Abstracts by author or title
(results will display both Free Papers & Poster)

Session Details

Session Title: Cataract
Session Date/Time: Saturday 10/02/2018 | 08:30-11:00
Paper Time: 09:36
Venue: Blue Hall

First Author: N.Hirnschall AUSTRIA
Co Author(s): O. Findl  T. Buehren  M. Trost           

Abstract Details


To evaluate spherical equivalent (SEQ) post-op refractive outcomes of a new raytracing based IOL power calculation method using IOLMaster 700 individualized eye model (IEM) data, a physical lens position (PLP) predictor, retinal image quality metrics (RIQM) criteria for IOL power selection and exact CT Asphina 409 MP IOL design information in comparison with Haigis formula.


Hanusch Hospital


Post-operative refractive outcome was assessed at a minimum of 4 weeks after surgery. Additionally, IOLMaster 700 raw data was collected pre- and at least 4 weeks post-surgery. Carl Zeiss Meditec internal prototype software was applied to generate individual eye models from pre- and post-surgical data including central corneal topography of front and back surfaces, anterior chamber depth, lens or IOL thickness and axial length. Retrospective raytracing based IOL power calculation was performed using RIQM criteria for IOL power selection in an iterative procedure and retinal Image simulations were performed.


Results present preliminary data of 65 eyes of 65 patients. Data collection is ongoing. Median- and mean absolute prediction error of SEQ was 0.02 D and 0,38D for raytracing and 0,12D and 0,42D for Haigis formula respectively. Minimum to maximum deviation of SEQ from target was -1,03D to +1,00D for raytracing and -1,06D to +1,13D for Haigis formula respectively. Prediction errors larger ±1.00D away from target refraction was lower in the raytracing group (n = 2) compared with the Haigis group (n = 13). Data for irregular corneas will be presented at the meeting


Raytracing based IOL power calculation using IOLMaster 700 IEM data, PLP prediction, RIQM based IOL power selection and exact IOL design information shows promising preliminary results not only for SEQ outcome performance but also for surgeon and patient education as well as management of patient expectations.

Financial Disclosure:

is employed by a forNoneprofit company with an interest in the subject of the presentation

Back to previous