Observational study comparing patients with inter-eye asymmetric keratoconus with patients with inter-eye symmetric keratoconus.

Detailed description: Keratoconus is a condition resulting in corneal thinning and visual impairment due to irregular astigmatism. Most cases are bilateral, although the severity is often asymmetric between both eyes. The aim of our study is to examine risk factors for inter-eye asymmetry in terms of severity in patients with a confirmed diagnosis of keratoconus. Patients were reviewed for keratoconus staging for each eye according to the Amsler-Krumeich classification to define asymmetry and separated in groups according to the laterality of the worst eye and in a group where both eyes were symmetric in terms of asymmetry. A multivariate logistic regression was performed on various risk factors to explore keratoconus inter-eye asymmetry.

Inclusion Criteria:

• Patients presenting to the attending ophthalmologist during the study period with previously diagnosed unilateral or bilateral keratoconus
• Patients newly diagnosed with unilateral or bilateral keratoconus during the study period.

Exclusion Criteria:

• Previous corneal surgery
• Previous corneal crosslinking
• Previous keratoplasty
• Previous placement of intrastromal corneal rings

Patients presenting to the attending ophthalmologist during the study period with previously diagnosed unilateral or bilateral keratoconus or patients newly diagnosed with unilateral or bilateral keratoconus during the study period.

According to French law and the guidelines of the French Data Protection Authority (CNIL), individual participant data cannot be publicly shared. However, study findings will be disseminated through peer-reviewed publications and presentations at scientific conferences.