Hospital das Clínicas Medical School of Ribeirao Preto University of Sao Paulo Ribeirao Preto 14049-900 Brazil;
Department of Ophthalmology Otorhinolaryngology Head and Neck Surgery Medical School of Ribeirao Preto University of Sao Paulo Ribeirao Preto 14049-900 Brazil;
keratoconus; cross-linking; corneal pachymetry; corneal topography; corneal opacity;