Effect of femtosecond laser setting on visual performance after small-incision lenticule extraction for myopia.

Abstract

AIM:

To compare the effect of the two femtosecond laser settings on visual performance after small-incision lenticule extraction (SMILE) for myopia and myopic astigmatism.

METHODS:

Forty-four eyes of 22 consecutive patients who underwent SMILE with an energy level of 140 nJ (spot distance 3.0 µm) in one eye, and with an energy level of 170 nJ (spot distance 4.5 µm) in the other eye, the eyes being randomly assigned. Preoperatively, 1 week, and 1 and 3 months postoperatively, the values of the modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scattering index (OSI) and Optical Quality Analysis System (OQAS) values (OVs) for these eyes were quantitatively assessed using an Optical Quality Analysis System (Visiometrics).

RESULTS:

No significant differences were detected between the two groups in the visual and refractive outcomes, or in the MTF cutoff frequency, the Strehl ratio, the OSI, the OV 100%, the OV 20% or the OV 9% at any time point before or after surgery.

CONCLUSIONS:

SMILE with energy settings of 140 and 170 nJ was effective for the correction of myopia and myopic astigmatism. It is indicated that the differences in laser setting (140 nJ, spot distance 3.0 µm vs 170 nJ, spot distance 4.5 µm) did not significantly affect the optical quality including the intraocular scattering of eyes undergoing SMILE.

CLINICAL TRIAL NUMBER:

The protocol was registered with University Hospital Medical Information Network Clinical Trial Registry (UMIN000016241).

• Authors: Kazutaka Kamiya, Kimiya Shimizu, Akihito Igarashi, Hidenaga Kobashi
• Journal: The British journal of ophthalmology (Br J Ophthalmol) Vol. 99 Issue 10 Pg. 1381-7 (Oct 2015) ISSN: 1468-2079 [Electronic] England
• PMID: 25855501 (Publication Type: Journal Article, Randomized Controlled Trial)
• Copyright: Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Topics

• Adult
• Corneal Stroma (surgery)
• Corneal Surgery, Laser (methods)
• Female
• Follow-Up Studies
• Humans
• Lasers, Excimer (therapeutic use)
• Male
• Myopia (physiopathology, surgery)
• Postoperative Period
• Prospective Studies
• Refraction, Ocular
• Visual Acuity