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Small incision lenticule extraction outcomes in population over 40 years of age

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First Author: J.Alio Del Barrio SPAIN

Co Author(s):    L. Primavera   M. Canto-Cerdan   J. Alió              

Abstract Details


To evaluate the influence of patient’s age at the time of surgery on SMILE refractive outcomes. Although SMILE refractive outcomes have been extensively reported, only one study have reported, independently, SMILE outcomes in a presbyopic population. Moreover, no study had focused before on comparing the SMILE outcomes between groups of different age. SMILE is an intrastromal refractive procedure, however, corneal stroma stiffness changes with age (by a progressive increase). In consequence, biomechanical response of the corneal stroma to the lenticule extraction, and so the refractive response, could differ depending on recipient's age.


Vissum Corporación and Universidad Miguel Hernández, Alicante, Spain.


Retrospective, consecutive, comparative study. We compared the refractive outcomes from two groups of patients divided by age (≤35 and ≥40 years) that underwent myopic SMILE 2016 and 2019 at out center. All eyes were evaluated preoperatively and at 1 and 6 months postoperatively. Main outcome measures were differences on efficacy, safety, predictability, and astigmatic changes by vector analysis with ASSORT software between both study groups (patients ≤ 35 and ≥ 40 years of age).


102-matched eyes of 53 patients were included. Preoperatively, we evidenced no differences in the mean SE or astigmatism between both groups. However, 6 months postoperatively we observed a significant difference in the mean astigmatism (p=0.019) while not in the SE, with a mild trend toward undercorrection of the refractive astigmatism in ≥40group. We observed a significant difference in the efficacy (0.86-1 month and 0.97-6 months in ≥40group versus 0.97-1 month and 1.07-6 months in the ≤35group; p=0.003) and safety indexes (0.93-1 month and 1.04-6 months in ≥40group versus 1.0-1 month and 1.11-6 months in the ≤35group; p=0.008) at 6 months.


Post-SMILE refractive outcomes in those patients over 40 years of age, although acceptable, are not as good as those obtained in younger patients, showing a significantly lower efficacy and safety indexes, and poorer astigmatic outcomes, with a tendency towards undercorrection. We hypothetize that the increased corneal stiffness in the aged group modifies the post-SMILE corneal stroma remodeling, thus affecting the refractive response and probably masking part of the astigmatic correction. Further studies with larger samples will help to confirm this outcomes reported for the first time. Surgical nomograms need to be adjusted in patients over 40 years of age.

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