Astigmatic Vector Analysis of Posterior Cornea - a Comparison Among Healthy, Forme Fruste and Overt Keratoconus Corneas

Astigmatic Vector Analysis of Posterior Corneal Surface - a Comparison Among Healthy, Forme Fruste and Overt Keratoconus Corneas

The main purpose of this study is to determine new diagnostic criteria for an eye disease called keratoconus.

Eyes of patients who distinctly present signs of keratoconus, for both eyes, at corneal tomography (an exam commonly used in such cases), and those who present such signs in only one eye were compared to eyes of unaffected patients. Several characteristics of anterior and posterior corneal astigmatism (special emphasis was given to the latter) were collectively assessed among all patients by a method referred to as vectorial analysis. Statistical tests were then performed, in an attempt to highlight differences among those three groups of patients and, eventually, define new diagnostic criteria.

Inclusion Criteria:

• Good-quality Scheimpflug scans (approved by the device in the ''Examination Quality Specification'').

Exclusion Criteria:

• Previous eye surgery or trauma, and any sort of corneal scarring that might interfere with keratometric data acquisition.