The purpose of this study is long-term follow up of patients with corneal diseases to analyze the quality of surgical interventions and diagnosis. Corneal ectasia, especially keratoconus, is a corneal disease that leads to an irreversible loss of visual acuity while the cornea becomes steeper, thinner and irregular. For these patients, surgical intervention (e.g. corneal cross-linking) is performed, in case of disease progression. Overall, a long-term follow up is needed to evaluate an early disease progression as well as corneal stability after surgical intervention.

Corneal ectasia (e.g. keratoconus) is a corneal disease that is characterized by irregular steepening of corneal curvature, stromal thinning and reduced biomechanical properties. As a result of this, visual acuity is reduced and can improved by spectacles in early state or with rigid gas permeable contact lenses in mild as well as advanced stage of the disease. Furthermore, in moderate and advanced cases stromal scarring occurs that affected the vision negatively. Therefore, a corneal transplantation is needed. Since the introduction of corneal cross-linking, the amount of corneal transplantations has been reduced. It is necessary to perform closely examinations to detect the progression of the disease as well as post-operatively follow-ups to confirm treatment success.

Parameters being analyzed are:

Age, sex, refraction, family history, known duration of ectasia, previous ocular surgery, systemic diseases, systemic and topical medication;

biomicroscopy, anterior optical coherence tomography (OCT), Scheimpflug-based tomography (Pentacam), Biomechanical assessment (Ocular Response Analyzer and Corneal Visualization with the Scheimpflug Technology), optical biometry, confocal microscopy, endothelium cell count.

Inclusion Criteria:

• corneal disease
• corneal ectasia

Exclusion Criteria:

• pregnancy
• age under 18 years

Patients with corneal diseases attending a University Hospital Corneal Diseases Service.