Corneal confocal microscopy differentiates inflammatory from diabetic neuropathy

Area of Science:

• Neurology
• Ophthalmology
• Immunology

Background:

• Immune-mediated neuropathies like CIDP are treatable but challenging to diagnose in diabetic patients.
• Corneal confocal microscopy (CCM) detects corneal nerve damage and inflammation.
• Distinguishing CIDP from diabetic neuropathy in coexisting cases is difficult.

Purpose of the Study:

• To assess CCM's ability to differentiate diabetic neuropathy from CIDP.
• To determine if CCM can detect CIDP in individuals with diabetes.

Main Methods:

• A multicenter, case-control study involving participants with CIDP (with/without diabetes), diabetes (with/without neuropathy), and healthy controls.
• Corneal confocal microscopy (CCM) was performed on all participants.
• Quantification of corneal nerve fiber density (CNFD), length (CNFL), branch density (CNBD), and corneal cell densities (dendritic and non-dendritic) was conducted.

Main Results:

• Dendritic cell density near corneal nerves was significantly higher in CIDP patients (with/without diabetes) versus diabetic neuropathy patients and controls.
• CNFD, CNFL, and CNBD were similarly reduced across CIDP, diabetic neuropathy, and CIDP with diabetes groups.

Conclusions:

• Elevated corneal dendritic cell density is a marker for CIDP.
• CCM shows potential for differentiating inflammatory (CIDP) from non-inflammatory diabetic neuropathy.