The Characteristics and Risk Factors of Very Asymmetric Keratoconus

Area of Science:

• Ophthalmology
• Corneal Diseases
• Epidemiology

Background:

• Keratoconus (KC) is a progressive corneal ectasia.
• Very asymmetric KC presents with KC in one eye and normal topography in the fellow eye.
• Understanding risk factors in diverse populations is crucial for early detection and management.

Purpose of the Study:

• To characterize very asymmetric KC in the Japanese population.
• To compare clinical demographics and risk factors between very asymmetric KC and typical KC.
• To investigate potential associations with hand dominance and KC laterality.

Main Methods:

• Retrospective review of clinical records of patients with very asymmetric KC and typical KC.
• Patient questionnaires on risk factors including family history, atopy, allergies, eye rubbing, and hand dominance.
• Subgroup analysis of very asymmetric KC based on KC severity (mild vs. severe).

Main Results:

• No significant differences in reported risk factors (eye rubbing, allergy, atopy) between very asymmetric KC and typical KC groups.
• Approximately half of very asymmetric KC patients had KC in the eye ipsilateral to their dominant hand, with no significant association found.
• Atopy and asthma were more frequent in the mild KC subgroup compared to the severe KC subgroup.

Conclusions:

• Patient-reported frequencies of eye rubbing, allergy, and atopy are comparable between typical KC and very asymmetric KC.
• No association was identified between hand dominance and the laterality of KC.
• These findings contribute to the understanding of KC heterogeneity and risk factors in the Japanese population.