<b>Purpose: </b>To assess the diagnostic utility of corneal confocal microscopy (CCM) for
diabetic peripheral neuropathy (DPN) and the risk factors for corneal nerve
loss.
<p><b>Methods: </b>490 participants
including 72 healthy controls, 149 with type 1 diabetes and 269 with type 2 diabetes
underwent detailed assessment of peripheral neuropathy and CCM in relation to
risk factors.</p>
<p><b>Results: </b>Corneal nerve fibre density (CNFD) (P<0.0001, P<0.0001), branch density (CNBD)
(P<0.0001, P<0.0001) and length (CNFL) (P<0.0001, P=0.02) were
significantly lower in patients with type 1 and type 2 diabetes, compared to
controls. CNFD (P<0.0001), CNBD (P<0.0001) and CNFL (P<0.0001) were
lower in type 1 diabetes compared to type 2 diabetes. Receiver operating
characteristics (ROC) curve analysis for the diagnosis of DPN demonstrated a
good area under the curve (AUC) for CNFD=0.81, CNBD=0.74 and CNFL=0.73. Multivariable regression analysis showed a
significant association between reduced corneal nerve fibre length with age
(β=-0.27, P=0.007), HbA1c (β=-1.1, P=0.01) and weight (β=-0.14, P=0.03) in
patients with type 2 diabetes and with duration of diabetes (β=-0.13, P=0.02), LDL
cholesterol (β=1.8, P=0.04), and triglycerides (β=-2.87, P=0.009) in patients
with type 1 diabetes. </p>
<b>Conclusion: </b>CCM
identifies more severe corneal nerve loss in patients with type 1 compared to type
2 diabetes and shows good diagnostic accuracy for DPN. Furthermore, the risk
factors for a reduction in corneal nerve fibre length differ between type 1 and
type 2 diabetes.
Corneal Confocal Microscopy Predicts 4-Year Incident Peripheral Neuropathy in Type 1 Diabetes
