Epithelial Remodeling And Epithelial Wavefront Aberrometry After Spherical Versus Cylindrical Myopic Small Incision Lenticule Extraction (Smile)
Published 2024 - 42nd Congress of the ESCRS
Reference: FP12.05 | Type: Free paper | DOI: 10.82333/1hgw-4p41
Authors: Nikolaus Luft* 1 , Barbara Brunner 1 , Stefan Kassumeh 1 , Lukas Feldhaus 1 , Wolfgang Mayer 1 , Martin Dirisamer 1 , Siegfried G. Priglinger 1
1LMU Munich,Munich,Germany
Purpose
To compare the epithelial thickness changes and the changes of epithelial wavefront aberrometry following purely spherical versus astigmatic myopic small incision lenticule extraction (SMILE).
Setting
Department of Ophthalmology, LMU University Hospital, Munich, Germany
Methods
Eighty-six eyes of 86 patients who underwent SMILE were included in this retrospective study. A total of 43 eyes had undergone myopic spherical correction (spherical group) and 43 eyes had undergone myopic cylindrical correction (cylindrical group). The groups were matched according to their spherical equivalent of surgically-corrected refraction. Subjective manifest refraction as well as high-resolution anterior segment optical coherence tomography (MS-39; CSO; Florence, Italy) were obtained preoperatively as well as 3 months postoperatively. The latter was utilized for computing epithelial wavefront aberrometry in addition to epithelial thickness mapping.
Results
Epithelial thickness increased significantly in both groups after SMILE (p<0.01). In the cylindrical group, epithelial thickening was more pronounced on the flat meridian as compared to the steep meridian (p=0.04). In both groups, epithelial wavefront aberrometry showed a significant postoperative increase in the epithelium’s spherical refractive power causing a myopization of -0.24 ± 0.42 diopters (D) in the spherical group (p<0.01) and -0.41 ± 0.52 D in the cylindrical group (p<0.0001). While no significant changes in epithelial cylindrical refractive power was observed in the spherical group, a significant increase was noted in the cylindrical group from -0.21 ± 0.24 D to -0.37 ± 0.31 D (p=0.01).
Conclusions
Postoperative epithelial remodeling after SMILE alters lower-order (sphere and cylinder) and higher order aberrations of the corneal epithelial wavefront and might contribute to refractive undercorrection. Epithelial wavefront aberrometry can be used to quantify the refractive effect of epithelial remodeling processes after keratorefractive surgery.