The Genetic Epidemiology and Omics of age-related cataract 

Abstract

Age-related cataract is the leading cause of blindness worldwide and a major public health problem. The two most common types of age-related cataract are nuclear and cortical cataract. Nuclear and cortical cataracts are complex diseases, meaning both genetic and environmental factors play a role in their pathogenesis. In addition, it is increasingly clear that pathogenesis of age-related cataracts is intertwined with systemic factors related to ageing. Holistic approaches taking into account the systemic nature of the cataract risk factors are needed. High-throughput technologies have enabled detailed studies of the molecular changes and biological pathways underlying a variety of complex traits but their use in age-related cataract research is long overdue.
The current thesis describes the implementation of various “omics” platforms to answer questions related to genetic and environmental risks such as: 1) What are the genetic variants (both common and rare) that underlie the pathogenesis of the common forms of age-related cataract: nuclear and cortical cataract?; 2) Do nuclear and cortical share genetic risk factors?; 3) What are the effects of diet on cataract formation and progression and are these effects mediated through circulating metabolites or the gut microbiome?
The work presented in this thesis resulted in, among others: the identification of six new genetic loci for age-related nuclear cataract; determining that dietary vitamin C protects not only against cataract formation but also against cataract progression; and suggesting that gut bacteria may play a role in the pathogenesis of cataract. Omics data can be useful for elucidating the biological pathways underling cataract. However, various factors that lead to reduction in power to identify effects, such as mismatches between dates of phenotyping and sample collection, may limit their potential.

Date of Award	2018
Original language	English
Awarding Institution	King's College London
Supervisor	Chris Hammond (Supervisor) & Pirro Hysi (Supervisor)