No Strong Association between the Apolipoprotein E E4 Allele and Glaucoma: A Multicohort Study.

Area of Science:

• Ophthalmology
• Genetics
• Neuroscience

Background:

• The apolipoprotein E (APOE) gene, particularly the E4 allele, is a significant risk factor for Alzheimer's disease and other neurodegenerative conditions.
• Its potential role in other complex diseases, including glaucoma, remains less understood.

Purpose of the Study:

• To investigate the association between the apolipoprotein E (APOE) E4 allele and the prevalence of glaucoma in large, multi-ethnic cohorts.
• To determine if APOE E4 influences glaucoma risk or is associated with other ocular conditions.

Main Methods:

• A cross-sectional analysis of over 438,000 UK Biobank participants of European ancestry.
• Replication analyses were conducted using data from the Canadian Longitudinal Study of Aging (CLSA), the Australian and New Zealand Registry of Advanced Glaucoma (ANZRAG), and the Blue Mountains Eye Study (BMES).
• APOE genotypes were determined and compared with glaucoma status, alongside positive and negative control outcomes.

Main Results:

• The APOE E4 allele was inversely associated with glaucoma in the UK Biobank cohort (OR, 0.96).
• This association was not replicated in the CLSA or ANZRAG/BMES cohorts.
• A positive association was observed between Alzheimer's dementia and both glaucoma and cataract.

Conclusions:

• The observed inverse association between APOE E4 and glaucoma in the UK Biobank cohort was not confirmed in replication studies.
• The findings suggest that the initial association may be an artifact, potentially due to underdiagnosis of glaucoma in APOE E4 carriers.
• Further research is needed to clarify the complex relationship between APOE genotype and ocular health.