Table 5.

Comparison of RNFL thickness, CSA of TN, and the combined index in the diagnosis of DPN.

		AUC	Confidence interval	Cutoff value	Sensitivity	Specificity
RNFL thickness	Overall average	0.675	0.587–0.755	103.50	0.713	0.690
	Superior quadrant	0.723	0.645–0.805	127.50	0.705	0.721
	Inferior quadrant	0.686	0.599–0.765	138.50	0.591	0.762
CSA of TN	At 1 cm	0.584	0.497–0.667	20.50	0.420	0.784
	At 3 cm	0.617	0.530–0.698	18.50	0.440	0.809
	At 5 cm	0.660	0.575–0.739	13.50	0.820	0.416
Combined index		0.755	0.664–0.846	0.376	0.643	0.830

RNFL, retinal nerve fiber layer; CSA, cross-sectional area; TN, tibial nerve; DPN, diabetic peripheral neuropathy; AUC, area under the curve.