Fig. 3: Quantification of RSOM features in participants with diabetic neuropathy.

The diabetic participants were grouped as follows: NC (n = 45), participants and no complications; LN (n = 13), participants with diabetes and low score neuropathy (1 ≤ NDS ≤ 5 or 1 ≤ NSS ≤ 5); HN (n = 12), participants with diabetes and high score neuropathy (NDS > 5 or NSS > 5). a Sectional RSOM image of healthy skin. b Sectional RSOM image of skin from a participant with diabetes but without neuropathy. c Sectional RSOM image of skin from a participant with diabetes and low score neuropathy (NDS: 3, NSS: 3). d Sectional RSOM image of skin from a participant with diabetes and high score neuropathy (NDS: 9, NSS: 9). MIP images of the EP and DR layers in the coronal views corresponding to (a–d) are displayed in (e–h) and (i–l) respectively. m–r Comparisons amongst the four groups of participants with diabetes and healthy volunteers for each of the six computed biomarkers. m Total number of small vessels (with diameter ≤40 µm) in DR layer. n Total number of large vessels (diameter >40 µm) in DR layer. o Total vessel numbers in DR layer. p Total blood volume in DR layer. q Thickness of EP layer. r Signal density of EP layer as a function of group studied. *P < 0.05, **P < 0.01, and ***P < 0.001, respectively. Scale bar = 500 µm. ns not statistically significant, NDS Neuropathy Disability Score, NSS Neuropathy Symptom Score, EP epidermis, DR dermis