Researchers from Australia and New Zealand investigated the relationship between corneal nerve structure and sensation in individuals with diabetes by using non-contact corneal esthesiometry to measure ocular sensitivity. The study found a moderate negative association between corneal nerve fiber length (CNFL) and corneal sensitivity thresholds to a cool stimulus. Also, the diabetic cohort had lower corneal nerve branch density (CNBD) and total branch density (CTBD) values. The team presented their findings at ARVO 2019.
The study compared comprehensive ocular assessments in 26 participants with diabetes with no or mild peripheral neuropathy symptoms with those of 15 healthy controls. Assessments included in vivo corneal microscopy and non-contact corneal esthesiometry with stimuli at room (~23°C) and cooled (18°C) temperatures.
Researchers found that sensitivity thresholds were higher in the diabetes group compared with controls for both room and cool temperature stimuli. The study found no differences for CNFL or corneal nerve fiber density between the two groups, and there was no significant correlation between CNFL and sensitivity thresholds in healthy controls.
The team concluded that the altered corneal structure-function relationship to cold stimuli in diabetic patients could indicate disease-related effects on certain sub-populations of corneal nerves.
|Zhang AC, Craig JP, Downie LE. Changes to corneal sensitivity precede symptoms of peripheral neuropathy in diabetes. ARVO 2019. Abstract 3241.|