Modelo de superficie corneal posterior a partir de topografía corneal anterior y paquimetría topográfica

Resumo

Introduction: Posterior corneal surface has been not well investigated and methods have not been completely developed, although there is no doubth about its importance because of its refractive implications and the consecuences derived from refractive surgery. Objetive: Design and application of a new method of estimating posterior corneal surface contour in healthy and round anterior corneal tipologed subjects. Methods: EyeSys 2000 Videokeratoscopy and ultrasonic topographic pachometry (Ophthasonic® A-Scan/Pachometer III) on 25 points in 10 corneas. Using the software Table Curve 3D and 2D both tridimensional profiles of anterior and posterior surfaces, and each one of the examined meridians will be reconstructed (0°-180°, 45°-225°, 90°-270°, 135°-315°). Results/Conclusions: The tridimensional surface equation that gets the best range of fit with the posterior corneal surface in round anterior corneal tipologed corneas corresponds with a generic equation of the rational polynomial type, getting a determination coefficient r²>0.990. Using the bidimensional representation the fit results more reliable, because it is made meridian by meridian, making evident the progresively increasing corneal thickness from center to periphery and estimating corneal thickness at each point of the examined area.