September 27, 2013

Metabolic profiling of vision loss

A panel of metabolites – small molecules that are part of metabolic processes – that are unique to macular degeneration will shed light on the disease and aid diagnosis.

(Wellcome Images)

Age-related macular degeneration (AMD) – in particular the type characterized by bleeding from retinal vessels (neovascular, NVAMD) – is a leading cause of irreversible vision loss in older individuals in developed countries.

Milam Brantley Jr., M.D., Ph.D., assistant professor of Ophthalmology and Visual Sciences, and colleagues sought to determine if plasma metabolic profiling could detect differences between NVAMD patients and controls. In a recent issue of PLOS ONE, they reported using a liquid chromatography-mass spectrometry method to scan the “metabolome” – all the small molecules that are part of metabolic processes – in plasma samples from 26 NVAMD patients and 19 controls. They found 94 unique features that differed between patients and controls. Further analysis revealed differences in diverse metabolic components ranging from peptides, bile acids and vitamin D to broader pathways like tyrosine and urea metabolism.

The results may lead to improved understanding of AMD pathophysiology and to biomarker discovery, which could improve diagnostic methods by confirming disease or disease risk prior to the appearance of clinical symptoms.

This research was supported by the National Institutes of Health (grants ES016731, AG038746, EY008126), a Jahnigen Career Development Award from the American Geriatrics Society, the Carl M. & Mildred A. Reeves Foundation, and an unrestricted departmental grant to Vanderbilt University from Research to Prevent Blindness.