Figure 6.

Representative in vivo clinical dTHGM images from the skin of the instep arch in the lower distal extremities and quantitative IENF index values derived for patients with DPN and controls

(A and D) Label-free bead-string-like in vivo dTHG signals (yellow arrows) in the human epidermis.

(B and E) Typical varicose structure (red squares) appeared for the unmyelinated FINEs in the epidermis.

(C and F) Magnified images revealing the varicose structures of 1 horizontally and 1 vertically oriented unmyelinated FINE with respect to the skin surface.

(G) A representative FINE signal showing at least 5 consecutive dot-like signals.

(H) The internal distance between 2 successive dot-like THG signals should be within 10.4 μm; these are 3.2, 3.2, 3.2, 3.7, and 1.8 μm for dots D1–D5, respectively.

(I) The same in vivo dTHGM image as (G) after discontinuous dot connection (red line) as 1 IENF.

(J) Patients with DPN had significantly lower IENF index values than did controls (∗p < 0.05; ∗∗p < 0.01).

(K) The IENF index values of patients with DPN and the IENF density derived from skin biopsies (on the distal part of the lower leg, 10 cm above the external malleolus) were highly correlated (Pearson’s correlation coefficient R = 0.98).

Scale bars, 50 μm.