Repeatability of ANTERION in subjects with keratoconus

Abstract

Aims/Purpose: The aim of this study was to study the repeatability of ANTERION in subjects diagnosed with keratoconus.Methods: The subjects selected had a previous diagnosis of keratoconus. These subjects were divided into three groups, according to the keratoconus treatment: subjects without treatment, intrastromal ring implantation and crosslinking. Subjects with pathologies with ophthalmological repercussion or previous surgeries were excluded.Three measures were performed with ANTERION in patients with keratoconus to evaluate the repeatability. These exams were performed with Cataract and Metricts module; therefore, six measurements were performed per patient and eye.Results: The parameters that showed values of coefficient of variation (CV) >5% in all the evaluated groups were: the vertical coma value, the difference between the thickness of the inferior–superior stroma and the eccentricity of the anterior and posterior corneal surface. In the groups with intrastromal ring segments and crosslinking, a CV >5% was obtained in the measurements of the minimum epithelial thickness and in the difference between the inferior–superior epithelial thickness. In the crosslinking and untreated groups, a CV >5% was obtained in the horizontal coma value. In the groups with intrastromal ring segments and without treatment, a CV >5% was obtained in the corneal RMS value and in the Score, which gives a value of the degree of keratoconus.The subjects implanted with intrastromal rings segments, a CV >5% was obtained in the measurements of the epithelial thickness at the point of greatest thickness.Conclusions: A parameter was considered to show low repeatability when its CV was >5%. The topographic measurements of K corneal and elevation values show good repeatability in subjects diagnosed with keratoconus. However, ANTERION shows a low repeatability in aberrometric values, and in measurements related to the stage and progression of the keratokonus.