Genetic diversity and medicinal drug response in eye care

Individual variation in drug response and adverse drug reactions are a serious problem in medicine. This inter-individual variation in drug response could be due to multiple factors such as disease determinants, environmental and genetic factors. Much has been published in the literature in recent years about the potential of pharmacogenetic testing and individualized medicine. The development of personalized medicine is truly an exciting area of research.

This pharmacogenetic concept in ophthalmology has existed for more than a century. Although substantial studies that link genetic variants to inter-individual difference in drug response have been reported in several diseases such as cancer and heart diseases, such studies are progressing slowly in the eye field. In this short article, an attempt has been made to summarize these results.

Recently, there have been some small-scale studies that seem to associate the drug response to the genotype of patients in two major eye disorders, namely age-related macular degeneration (ARMD) and glaucoma.

These studies are still in their infancy, and do not suggest that a pharmacogenetic basis of drug development is a credible concept and can become reality in the future. This is because most drug responses involve a large number of genes that have several polymorphisms and it is unlikely that any one single gene dictates the drug response. Therefore, a polygenic approach, whole genome single nucleotide polymorphism (SNP) analysis and a molecular understanding of disease itself may provide a better insight in the future about genetic predisposing factors for adverse drug reactions.