Decentration Not Correlated with Postoperative Visual Outcomes in SMILE

New Vision clinic, main center for refractive surgery in France, with cutting-edge technology for all eye laser operations. Eye operation using the SMILE, Small Incision Lenticule Extraction, laser technique. It is a new generation of treatment which enables short-sightedness to be corrected without removing the superficial layer of the cornea, nor opening it. The SMILE technique involves producing with the Femtosecond laser, a lenticule, thin slice, in 3D in the thickness of the cornea, and removing it with a micro incision in the shape of a smile. The worse the short-sightedness, the thicker the lenticule. (Photo by: BSIP/Universal Images Group via Getty Images)
The magnitude of decentration does not differ between eyes with satisfactory outcomes, and those with suboptimal outcomes, the report explains.

This article is part of Ophthalmology Advisor’s conference coverage from the 2021 meeting of American Society of Cataract and Refractive Surgery (ASCRS), held in Las Vegas from July 23 to 27, 2021. The team at Ophthalmology Advisor will be reporting on a variety of research presented by the cataract and refractive surgery experts at ASCRS. Check back for more from the ASCRS 2021 Meeting.


The magnitude of treatment decentration in eyes that have undergone small incision lenticule extraction (SMILE) surgery differs depending on whether decentration is determined using pachymetry maps or anterior tangential curvature maps, according to research presented at the American Society of Cataract and Refractive Surgery (ASCRS) meeting in Las Vegas, from July 23 to 27, 2021.

To determine the risk factors associated with decentration after SMILE surgery, researchers examined the percentage of visually significant decentered treatments in SMILE patients, the degree of decentration that impacts the visual outcome, and identified the intraoperative cues that may predict decentration. 

Investigators conducted a retrospective evaluation of all eyes that underwent SMILE for four years. Scheimpflug difference maps were used to identify treatment decentration, and intraoperative videos of all cases were reviewed to identify intraoperative cues that may have predicted treatment decentration.

They found that the average treatment decentration among these patients was 0.43±0.2 2 mm and 0.30±0.16 mm (P <0.001) based on pachymetry and anterior tangential curvature, respectively. Decentration was not correlated with postoperative sphere, cylinder, spherical equivalent, CDVA or UDVA (r2<0.1 for all). Three months postoperatively, 12 patients (18 eyes, 27%) were less than fully satisfied after surgery, while 27 patients (48 eyes, 73%) were satisfied. 

Based on anterior tangential curvature, average decentration was 0.36±0.17 mm and 0.28±0.16 mm (P =.09) in eyes with poor and satisfactory subjective outcomes, respectively, and 0.36±0.17 mm and 0.28±0.16 mm (P =.05) in eyes with suboptimal and adequate objective outcomes, respectively.

Disclosure: One study author declared affiliations with the biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.  

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Asroui L, Dupps W, Randleman J. Risk factors for small incision lenticule extraction (smile) treatment decentration. Presented at: 2021 ASCRS Annual Meeting; July 23-27, 2021; Las Vegas, NV. Poster 75090.