Characterisation of motion artefacts in the imaging of the ocular media

Session Details

Session Title: Cataract Surgery Outcomes. IOL Power Calculations

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

Paper Time: 18:16

Venue: Room 1

First Author: : P.Zakharov SWITZERLAND

Co Author(s): :    M. Talary   D. Boss   M. Mrochen              

Abstract Details

Purpose:

Eye motion is an essential function of our vision system. Even when fixating on a static object the eye undergoes “miniature” motion to prevent the image from fading away. This causes significant distortions for an ophthalmic investigation with high resolution imaging modalities, such as retinal or corneal optical coherence tomography. A general simulation framework has been developed for characterising eye motion artefacts in ophthalmic imaging of the ocular media. The optimisation of the scanning strategy for an OCT imaging of anterior chamber of the eye has been presented as the first application example.

Setting:

IROC Science, Zurich, Switzerland

Methods:

Based on the available literature and experimental measurements we have developed a theoretical spectral model for stochastic simulation of three dimensional eye motion. This model is implemented in an intuitive software package which allows virtual scans of the defined eye structures to be obtained based on a ray tracing algorithm. Simulation combines timing information related to the user-defined scanning strategy and technical specifications of the imaging hardware with simulated motion in time. Imaging data is simulated which is further analysed and compared with the expected results to evaluate performance.

Results:

Multiple sampling of the cornea surface with averaging of the fitted parameters decreases the error of derived cornea metrics, at the same time an increase in the number of sampling points leads to a longer measurement time and larger effect of the motion artefacts (due to motion energy concentration in the lower frequencies).

Conclusions:

The framework allows the testing of different scanning geometries, sequences and averaging approaches by performing simulations of the scanning performance for different eye shapes and motion realisations. In this way the user can design the optimal scanning strategy and hardware specifications for the application.

Financial Interest:

One of the authors gains financially from product or procedure presented