Pyramidal aberrometry in wavefront-guided myopic LASIK

Session Details

Session Title: LASIK II

Session Date/Time: Tuesday 25/09/2018 | 16:30-18:00

Paper Time: 17:04

Venue: Room A3, Podium 2

First Author: : A. Frings UK

Co Author(s): :    B. Allan   H. Hassan   A. Ieong              

Abstract Details

Purpose:

Pyramidal aberrometry has greater sampling density and a higher dynamic range than Hartman Shack Aberrometry. Here we present measurement repeatability data and early results for a pyramidal aberrometer in routine myopic LASIK.

Setting:

Moorfields Eye Hospital, London

Methods:

3 consecutive aberrometry scans were acquired for 50 consecutive cases (100 eyes) treated with myopic wavefront-guided LASIK using the AMARIS 1050RS excimer laser and PERAMIS pyramidal aberrometer (Schwind Eye-Tech-Solutions GmbH, Kleinostheim, Germany). Random-effects ANOVA was used to derive a standard deviation within patients (SDw) and limits of repeatability for the aberrometric refraction spherical equivalent (SE). Standard outcome reporting was used in analysis of manifest spherical equivalent results of treatment, and a multiple regression model was used to derive nomogram adjustments to the attempted spherical correction.

Results:

The 95% repeatability coefficient for the aberrometric SE was 0.51D (SDw=0.18D). The mean aberrometric SE was approximately 0.2D lower than the manifest refraction SE for the same patients, suggesting good control over accommodation during scanning. In an initial series of patients treated with intuitive adjustments to the attempted treatment sphere only, 96% were within ±0.50D of the intended target SE, and 97% had UDVA≤0.00 logMAR (≥20/20). Regression modeling suggested systematic adjustments to the treatment sphere taking account of the attempted aberrometric SE and the difference between the manifest refraction SE and the aberrometric SE.

Conclusions:

Spherical equivalent measurement repeatability in pyramidal aberrometry may be better than for manifest refraction, suggesting myopic LASIK results could be improved by using wavefront guided treatment routinely.

Financial Disclosure:

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