Peripheral aberrations in negative dysphotopsia

Session Details

Session Title: Cataract Surgery Complications

Session Date/Time: Monday 16/09/2019 | 16:30-18:00

Paper Time: 17:18

Venue: Free Paper Forum: Podium 2

First Author: : L.van Vught THE NETHERLANDS

Co Author(s): :    G. Luyten   J. Beenakker                          

Abstract Details

Purpose:

Negative Dysphotopsia (ND), commonly described as a dark shadow or missing part of the peripheral visual field, is a complaint that can occur directly after cataract surgery. The major challenge in the treatment of ND is the lack of knowledge on its exact origin. In this study, we studied the peripheral aberrations of pseudophakic eyes with and without ND using in vivo corneal topography and peripheral wavefront aberration measurements. Additionally, we performed ray tracing simulations to provide a first clinical assessment of the optical factors contributing to ND.

Setting:

Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden, the Netherlands.

Methods:

Fifty-seven pseudophakic eyes of twenty-seven ND-patients and thirty pseudophakic controls were prospectively evaluated. From the corneal topography (Pentacam, Oculus), the total corneal wavefront of the central 8.0 mm of the cornea was calculated and subsequently compared between both groups. The peripheral wavefront aberrations (VPR, vOptica) were measured up to 30 degrees eccentricity, converted into spherical equivalent of refraction (SE), astigmatism and spherical aberration, and compared between both groups. Additionally, the effect of alterations in the intraocular lens (IOL) position on the peripheral refraction was evaluated through ray-tracing simulations (OpticStudio, Zemax) using a pseudophakic version of the Escudero-Sanz eye-model.

Results:

No significant relation was found between the total corneal wavefront and the presence of ND, with all logistic regression p-values being 0.12 or higher. The peripheral aberrations at 30 degrees nasal visual filed eccentricity show a significant difference, with a median SE relative to central refraction of -3.4 Diopter in ND-patients and -1.6 Diopter in pseudophakics controls (p = 0.038). At temporal eccentricities, these median SEs were -1.4 and -1.2 Diopter respectively (p = 0.892). The ray tracing analysis show that this assymetry in peripheral SE could be the result of a temporally decentered or tilted IOL.

Conclusions:

Although no significant differences in corneal power was found in ND-patients compared to pseudophakic controls, the peripheral aberration measurements show a stronger myopic SE in the nasal peripheral visual field. Ray tracing analyses show that this asymmetry can be explained by a temporally decentered or tilted IOL. This is in line with some of the main hypotheses on the origin of ND, that assume that the perception of ND is caused by the passage of light between the nasal iris and IOL. As a result, this study provides valuable, objective, insight in the origin of ND.

Financial Disclosure:

None