To compare the induced corneal wavefront aberration of
eyes treated for myopia by LASIK with the SCHWIND ESIRIS laser using an
aspheric aberration-neutral (Aberration-Free™) ablation profile versus a
classical Munnerlyn standard profile.
Two consecutive groups of myopic eyes were analyzed. One
group (70 eyes) was treated with a standard non-aspheric Munnerlyn profile
(standard group, mean spherical equivalent refraction –4.09±1.77
diopters [D] [range: –7.75 to –0.75 D] and mean cylinder
0.78±0.76 D [range: 0.00 to 3.00 D]), and the second group (70 eyes) was
treated with the ORK-CAM aspheric aberration-neutral profile
(aberration-neutral group, mean spherical equivalent refraction
–3.71±1.80 D [range: –8.25 to –0.75 D] and mean cylinder
1.00±0.97 D [range: 0.00 to 4.50 D]). Visual outcome, corneal wavefront
data, and topographic changes after 3-month follow-up were compared.
Both groups had a good visual acuity outcome with
refractive predictability of ±0.50 D in approximately 96% of the cohort.
In terms of safety, one eye in the standard group lost two lines of Snellen
visual acuity. In the aberration-neutral group, no eye lost more than one line
of Snellen visual acuity and 6% gained more than two lines. Corneal aberrations
were measured up to the 7th order (36 Zernike terms). The induced postoperative
corneal wavefront aberration at 4.0 and 6.0 mm was compared. At 6.0 mm, corneal
coma increased after myopic LASIK by 0.09 µm in the standard group and by
0.07 µm in the aberration-neutral group. The induction of corneal
spherical aberrations in the standard group was 0.17 µm (0.22 D) versus
0.09 µm (0.13 D) in the aberration-neutral group. The root-mean-square of induced higher order aberrations
was 0.19 µm in the standard group and 0.16 µm in the
aberration-neutral group. Topographies showed multifocality of 0.50 D in the
standard group and 0.25 D in the aberration-neutral group.
Both groups had good predictability and safety results.
With the aspheric aberration-neutral profile, less corneal wavefront aberration
was induced compared to eyes treated with the standard profile. [J Refract
From Augenlaserzentrum Recklinghausen, Recklinghausen,
Dr de Ortueta is a consultant and Mr Arba Mosquera is an
employee of SCHWIND eye-tech-solutions GmbH (Germany). Dr Baatz has no
proprietary interest in the materials presented herein.
Correspondence: Diego de Ortueta, MD, FEBO,
Augenlaserzentrum Recklinghausen, Erlbruch 34-36, 45657 Recklinghausen,
Germany. Tel: 49 2361 3069770; Fax: 49 2361 3069799; E-mail:
Received: September 15, 2007; Accepted: May 6, 2008
Posted online: July 31, 2008