Wavefront and higher order aberration Zernike co-efficients induced by a corneal shape-changing inlay

Session Details

Session Title: Intracorneal Inlays for Presbyopia

Session Date/Time: Tuesday 08/09/2015 | 16:00-18:00

Paper Time: 17:12

Venue: Main Auditorium

First Author: : J.Güell SPAIN

Co Author(s): :    E. Barragan   A. Chayet                 

Abstract Details

Purpose:

Demonstrate that induction of significant higher order aberrations (HOAs) is necessary due to the center-near power profile created by an anterior corneal surface shape-changing inlay.

Setting:

Institute of Ocular Microsurgery, Barcelona, Spain and Laser Ocular Hidalgo, Monterrey Mexico, CODET Vision Institute, Tijuana Mexico.

Methods:

Preoperative and postoperative wavefront (WF) scans were recorded for 150 presbyopic emmetropic and low hyperopic subjects (eyes) implanted with the Raindrop Near Vision Inlay, centered on the light constricted pupil. The average WF difference map was calculated and the measured optical path difference (OPD) was converted to anterior corneal surface height change (microns) by dividing by (1.376 – 1). The mean change in each Zernike coefficient was calculated. Changes in visual acuity were recorded.

Results:

The wavefront difference map indicates a maximum anterior corneal surface change of about 8 microns tapering outwards over a central region with a diameter of about 3.5 mm. This induces myopic refractive power at the center of the pupil, providing significant improvement in near vision. Zernike analysis over the central, altered region of the pupil reveals that defocus (Z2,0) and spherical aberration (Z4,0) dominate the Zernike terms with only small contributions from asymmetric terms. When extending the analysis to the periphery, higher order symmetric terms (Z6,0,etc.) must be added to account for the largely unperturbed outer regions.

Conclusions:

The Raindrop Inlay induces a center-near “Profocal” power profile that, by necessity, induces beneficial higher order aberrations, leading to a myopic refractive change in the central pupil, contributing to improved near visual function. The periphery of the pupil remains approximately unchanged, retaining good distance function for these emmetropic and low hyperopic subjects.

Financial Interest:

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