Corneal subepithelial microneuromas (CSEMNs) and axonal swelling have been explored in people with painful small fibre neuropathies using non-invasive corneal confocal miscroscopy.  Whether CSEMNs are more commonly observed in painful neuropathies is debated. The presence and categorisation of different types of corneal microneuromas in people with diabetes, with and without painful distal symmetrical polyneuropathy (DSPN) is yet to be explored. 

This cross-sectional study showed an increased presence and larger number of axonal swellings in people with painful DSPN compared to people with non-painful DSPN. Additionally, axonal distension (a type of CSEMNs) was increased in people with painful and non-painful DSPN compared to people with diabetes without DSPN and people without diabetes. The use of corneal confocal metrics like axonal swelling and CSEMNs may help in understanding individual pathomechanisms in people with (painful) DSPN. This will help clinicians with more targeted interventions.