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Guillermo Tapia-Herrera, Fiona Xacur, Alejandro Navas, Salomon Fermon, Enrique Graue-Hernandez, Tito Ramirez-Luquin; Refractive, Topographic And Aberrometric Characteristics Of Keratoconus Eyes Before And After Intacs Sk Intracorneal Ring Segments Implantation. Invest. Ophthalmol. Vis. Sci. 2011;52(14):5753.
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© ARVO (1962-2015); The Authors (2016-present)
Quantify and compare anterior corneal optical aberrations as well as topographic and refractive characteristics in patients with keratoconus before and after implantation of INTACS SK intracorneal ring segments (ICRS).
Retrospective analysis of patients implanted with Intacs SK ICRS between March and November 2009. The topographic characteristics were determined based on the axial curvature map from the corneal tomography study by Scheimpflug images, Pentacam (Oculus). The anterior corneal optical aberrations coefficients of the third and fourth order were determined through Zernike's polynomial analysis of the Pentacam. Statistical analysis was conducted with SPSS for Windows 15.0, a T student method and statistical significance for a p value ≤ 0.05
25 eyes, 15 patients, with an average age of 26.4 years were included. UCVA improved from 1.264 (logMAR) preoperatively to 0.509 after the procedure (p=0.0001). Average preoperative spherical equivalent was -8.871 diopters decreasing to -4.744 diopters after implantation (p=0.0001). Flattest average keratometry was 46.83 diopters and decreased to 43.83 diopters postoperatively (p< 0.0001), and the steepest keratometry was 52.27 diopters and decreased to 48.06 diopters after surgical intervention (p< 0.0001). At a 3mm simulated pupil diameter, a 0.141µm (p=0.007), 0.145 µm (p=0.018) and 0.222 µm (p=0.002) decrease was observed on the vertical coma, horizontal coma and total coma respectively, as well. No significant changes on trefoil or spherical aberration were seen. At a 5mm simulated pupil diameter, there was a 0.418 µm (p=0.0003), 0.497 µm (p=0.002) and 0.724 µm (p< 0.0001) decrease in horizontal, vertical, and total coma coefficients respectively, after the procedure. At a 5mm pupil, the coefficients for trefoil at 0 degrees and total trefoil decreased significantly in 0.130 µm (p=0.035) and 0.112 µm (p=0.044) respectively. No other significant changes were found at this pupil diameter.
INTACS SK intracorneal ring segments implantation on eyes with keratoconus produce a significant decrease in corneal curvature, refractive spherical equivalent and coma aberration coefficients and an improvement in UCVA. This procedure does not seem to provide a significant change in other aberration coefficients.
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