Corneal confocal microscopy: a non-invasive surrogate of nerve fibre damage and repair in diabetic patients

Aims/hypothesis. The accurate detection, characterization and quantification of human diabetic neuropathy are important to define at risk patients, anticipate deterioration, and assess new therapies. Corneal confocal microscopy is a reiterative, rapid, non-invasive in vivo clinical examination technique capable of imaging corneal nerve fibres. The aim of this study was to define the ability of this technique to quantify the extent of degeneration and regeneration of corneal nerve fibres in diabetic patients with increasing neuropathic severity. Methods. We scanned the cornea and collected images of Bowman's layer (containing a rich nerve plexus) from 18 diabetic patients and 18 age-matched control subjects. Results. Corneal nerve fibre density (F3=9.6, p<0.0001), length (F3=23.8, p<0.0001), and branch density (F3=13.9, p