Is the Eye a Window to the Peripheral Nerve? What the Shortest Nerves Have to Say About the Longest Ones.

Axonal peripheral neuropathy is one of the most common disorders of late adulthood, with a population prevalence of 9% among those older than 55 years, and the prevalence increases further with age.(1) The most common cause is diabetes, with half of diabetic people developing diabetic peripheral neuropathy (DPN). DPN is a major cause for disability due to pain, foot ulceration, and amputation. The second most common cause of axonal neuropathy is idiopathic, and this condition shares many pathophysiologic and clinical features with DPN.(2) A major barrier to therapeutic development for preventative and disease-modifying therapies for axonal peripheral neuropathy is the lack of a practical and scalable biomarker that is clinically meaningful and responsive and has predictive validity for incident disease in high-risk populations.