Q-factor as a descriptor of the refractive dysfunction of the lens

Session Details

Session Title: Advanced Tools for Outcome Assessment

Session Date/Time: Tuesday 17/09/2019 | 08:30-10:30

Paper Time: 09:00

Venue: Free Paper Forum: Podium 4

First Author: : V.Molebny UKRAINE

Co Author(s): :    O. Molebna   J. Wakil   I. Pallikaris                       

Abstract Details

Purpose:

Dysfunctional Lens Index (DLI), recently developed and incorporated into the iTrace software, is an indicator scaled to 10-level indexing that warns of the need to address the quality of vision requiring, under certain levels, an IOL implant. Its calculations use a proprietary algorithm operating with the intraocular aberrations. The DLI evaluates the dysfunction integrally, giving no information on its character. Since the lens contains structural elements (fiber cells) oriented along radii and meridians, they should result in different types of aberrations.

Setting:

In our studies, we used the database of Molebna Eye Clinic.

Methods:

We studied an approach based on the earlier described ocular Q-factor, but focused on internal ocular aberrations. In this approach, radial and tangential aberrations are compared to each other. In more detail, compared were the dispersions of the partial derivatives in radial and tangential (circular) directions correspondingly.

Results:

64 eyes of 32 patients having no vision complaints, older than 25 without any selection were analyzed. Standard deviations of radial and tangential components were calculated to get their ratio. The range of measured Q-factor of the lens was 1.79 – 4.38. Changing the accommodation results in shifting of the Q-factor up or down. Dominating eyes have higher Q-factor. We checked also the model eyes that demonstrated the Q-factor as high as 15.2. 3D (Visus, DLI, Q) presentations of the results were analyzed.

Conclusions:

The study confirmed the potential of the ray tracing aberrometry to analyze the refractive properties of the lens and to differentiate the dysfunction for the preemptive role of its different structural components, as well as their dynamics with accommodation, thus describing the dysfunction in more detail, and providing the higher-level professional decision making on the need of a timely surgery requiring an IOL implant.

Financial Disclosure:

None