Non-genetic risk factors for keratoconus

Area of Science:

• Ophthalmology and Environmental Health

Background:

• Keratoconus (KC) is a complex corneal disease with unknown etiology.
• Environmental factors are increasingly recognized as potential contributors to KC development.

Approach:

• A systematic review and meta-analysis of 30 studies was conducted to evaluate environmental risk factors for KC.
• Studies were sourced from major databases (Scopus, Web of Science, PubMed, Cochrane CENTRAL) published up to July 2021.
• Methodological quality was assessed using the NIH Quality Assessment Tool.

Key Points:

• Significant positive associations were found between KC and eye rubbing (OR=3.64), atopy (OR=1.90), asthma (OR=1.36), and eczema (OR=1.90).
• Use of sunglasses showed a protective effect (OR=0.40).
• Other factors like diabetes (OR=0.86), contact lens wear (OR=1.68), and allergic conjunctivitis (OR=2.24) showed varied associations.

Conclusions:

• Environmental factors, particularly eye rubbing and allergic conditions, play a role in keratoconus susceptibility.
• High-quality studies indicate a significant link between specific environmental exposures and keratoconus.
• Further large-scale longitudinal research is essential to elucidate the underlying mechanisms connecting environmental factors and keratoconus.