Wavefront and Higher-Order Aberration Zernike Coefficients Induced by Corneal Shape–Changing Inlay

Saturday, April 18, 2015: 3:44 PM
Room 3 (San Diego Convention Center)
José L. Güell, MD, PhD
Enrique Barragan, MD
Arturo S. Chayet, MD

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

Preoperative and postoperative wavefront (WF) scans were recorded for 10 presbyopic emmetropic 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.

The WF difference map demonstrates an anterior corneal surface change of about 10 microns, with the effect extending to about twice the inlay diameter.  This induces a myopic refractive power at the center of the pupil, which provides significant improvement in uncorrected near vision. Analysis of the change in HOA Zernike coefficients reveals that the largest changes occur in the symmetric Zernike coefficients (C20, C40, and C60), compared to the asymmetric coefficients. The pattern of symmetric coefficients contributes to the induced myopic refraction at the center of the pupil.

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