Relación entre las variaciones diurnas de espesor y curvatura corneal

Resumo

Purpose: The natural phenomenon of corneal thickness (CT) and curvature (CC) diurnal variation make difficult repeated measurement of both parameters. Our aim was determine the relationship between diurnal variations of central and paracentral CT and CC over a period of ten hours. Materials and methods: CT and CC of 10 right eyes of 10 young healthy men were measured by Orbscan Topography System and EyeSys videokeratoscopy, respectively. Both parameters were determined at center and at paracentral region of 1 mm and 2 mm from the center throughout the day, each two hours during ten hours. Results: The cornea was thickest and flattest on awakening. There was a difference in CT (ANOVA, Schefféc method, p < 0.05) and CC (ANOVA, Tamhane method, p < 0.05) over time in all the corneal locations studied, being the shift greater in peripheral corneal data. Changes in central and paracentral CT was strongly correlated with CC except for the 2 mm nasal and superior semi-meridians. Conclusions: These data evidence a significant relationship between CT and CC diurnal variations, where the thickness got thinner the curvature, got steeper.