Abstract
Purpose :
To investigate the amount of lenticule decentration following small-incision lenticule extraction by using the Keratron Scout tangential topography difference map, and to determine the relationship between the magnitudes of total decentration and induced corneal higher-order aberrations
Methods :
In this retrospective observational case series study, we analyzed decentration values using the Keratron Scout tangential topography difference map of 360 eyes (360 patients) that underwent small-incision lenticule extraction procedure. We measured root mean square total higher-order aberrations, root mean square third order coma aberration, root mean square fourth order spherical aberration, as well as individual coefficients for vertical and horizontal coma using the Keratron Scout preoperatively and 3-months postoperatively. To determine the relationship between the magnitudes of total decentration and induced corneal higher-order aberrations, we performed simple linear regression analysis and piecewise regression models.
Results :
The mean total decentration distance from the corneal vertex was 0.36 ± 0.22 mm (range, 0.02-1.27 mm). There were significant differences in total higher-order aberrations, coma aberration, vertical and horizontal comas, and spherical aberration between preoperative and 3-month postoperative assessments. Significant relationships between the magnitudes of total decentration and induced corneal higher-order aberrations were noted. Subgroup analysis according to the degree of total decentration (Group I, total decentered displacement ≤0.335 mm and Group II, total decentered displacement >0.335 mm) revealed that induced changes in total higher-order aberrations, coma aberration, vertical coma, and spherical aberration were significantly larger in Group II than in Group I.
Conclusions :
A minimal degree of decentration was closely related to a smaller induction of corneal higher-order aberrations. Therefore, efforts to optimize centration are critical for achieving better surgical outcomes in small-incision lenticule extraction procedure
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.