Corneal Tomography in Patients Undergoing LASIK with Femtosecond Laser: Preoperative and 3-Month Postoperative Study
DOI:
https://doi.org/10.71413/ctyd3w08Keywords:
Pentacam, LASIK, Topography, Elevation, PachymetryAbstract
Relevance: The study of corneal topography is essential in the preoperative assessment of Laser-Assisted In Situ Keratomileusis (LASIK). A new standardized method for the analysis of topographic maps would be useful to help ensure a successful surgical outcome.
Purpose: To design a new standardized method for the analysis of tomographic maps and use it to compare the maps of patients before undergoing LASIK surgery with femtosecond laser and three months after the procedure.
Methods: A total of 50 eyes from 25 patients were selected for the study. All had available tomographic data both before surgery and three months postoperatively. From these tomographies, data were extracted at 17 predefined corneal points, consistently located on each map: the coordinate origin, and at 1, 2, 3, and 4 mm in the temporal, nasal, inferior, and superior directions. These data were compiled in an Excel spreadsheet for further analysis. The corneal maps selected for evaluation included curvature, anterior elevation, and pachymetry.
Results: Statistically significant differences (p < 0.05) were found between preoperative and postoperative values across the entire anterior curvature map and only in the temporal area of the posterior curvature map. In pachymetry, significant differences were observed throughout the map except at 4 mm from the coordinate origin. Moreover, a strong correlation was identified between pre-postoperative differences in the anterior curvature maps' radius and the corrected spherical equivalent (greater ablation yielded greater differences), while only a weak correlation was found in pachymetric changes.
Conclusions: This study proposes a novel measurement approach for the analysis of tomographic maps, based on predefined and consistently used corneal points. This method enables a more precise and standardized evaluation of the corneal surface compared to previously available methodologies.
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