VARIAÇÃO DO ASTIGMATISMO ENTRE EXAMES TOMOGRÁFICOS EM PACIENTES COM CERATOCONE INICIAL

Abstract

Abstract Objective: Analyze the variation in the classification of astigmatism in the analyzed eyes and their respective variables, correlating them with their potential impacts on visual quality.Methods: This is an analytical cross-sectional study conducted between January 2022 and May 2023, involving 78 eyes diagnosed with keratoconus by a subspecialist using the Belin/Ambrosio Enhanced Ectasia criteria, utilizing the Pentacam® HR 70900 tomographer. The collected data included K1, K2, Km, anterior astigmatism, posterior astigmatism, pachymetry, anterior asphericity, posterior asphericity, ARTmax, corneal volume, D-index and its fractions (Da, Db, Dp, Dt, and Df), spherical power, cylindrical power, axis, and visual acuity with correction. The data were entered and managed in Excel for subsequent analysis using IBM® SPSS® software (Statistical Package for the Social Sciences). The variables were presented as mean, standard deviation, median, interquartile range (25% and 75%) (measures of dispersion), as well as minimum and maximum values.Results: A total of 78 eyes were analyzed, with a mean age of 28.2 at the time of the first examination and 29.05 years old at the time of the second examination. There was considerable variation observed when analyzing Posterior Astigmatism and the Db and Df indices, as they are directly correlated values related to the posterior astigmatism in patients with early keratoconus. Additionally, it was found that out of these 78 eyes, 12 underwent changes in classification, with 8 of them becoming oblique.Conclusion: The change in astigmatism classification to oblique in 9% of the analyzed sample may suggest a relationship between the alteration of astigmatism's type and a poorer prognosis of the disease, which is associated with oblique astigmatism.