AUTHOR=Petropoulos Ioannis N. , Bitirgen Gulfidan , Ferdousi Maryam , Kalteniece Alise , Azmi Shazli , D'Onofrio Luca , Lim Sze Hway , Ponirakis Georgios , Khan Adnan , Gad Hoda , Mohammed Ibrahim , Mohammadi Yacob E. , Malik Ayesha , Gosal David , Kobylecki Christopher , Silverdale Monty , Soran Handrean , Alam Uazman , Malik Rayaz A. TITLE=Corneal Confocal Microscopy to Image Small Nerve Fiber Degeneration: Ophthalmology Meets Neurology JOURNAL=Frontiers in Pain Research VOLUME=2 YEAR=2021 URL=https://www.frontiersin.org/journals/pain-research/articles/10.3389/fpain.2021.725363 DOI=10.3389/fpain.2021.725363 ISSN=2673-561X ABSTRACT=

Neuropathic pain has multiple etiologies, but a major feature is small fiber dysfunction or damage. Corneal confocal microscopy (CCM) is a rapid non-invasive ophthalmic imaging technique that can image small nerve fibers in the cornea and has been utilized to show small nerve fiber loss in patients with diabetic and other neuropathies. CCM has comparable diagnostic utility to intraepidermal nerve fiber density for diabetic neuropathy, fibromyalgia and amyloid neuropathy and predicts the development of diabetic neuropathy. Moreover, in clinical intervention trials of patients with diabetic and sarcoid neuropathy, corneal nerve regeneration occurs early and precedes an improvement in symptoms and neurophysiology. Corneal nerve fiber loss also occurs and is associated with disease progression in multiple sclerosis, Parkinson's disease and dementia. We conclude that corneal confocal microscopy has good diagnostic and prognostic capability and fulfills the FDA criteria as a surrogate end point for clinical trials in peripheral and central neurodegenerative diseases.