Quantitative evaluation of microvascular dysfunction in peripheral neuropathy with diabetes by indocyanine green...

Peripheral neuropathy in diabetes (PND) plays a central role in foot ulceration with diabetes, and leads to an abnormal microvascular structure, including arteriovenous shunting. To assess the extent of arteriovenous shunting we performed indocyanine green angiography (ICGA) in patients with diabetes and evaluated quantitative ICGA parameters.

Between November 2012 and July 2013, twenty-six limbs in 14 patients with PND and twenty-three limbs in 15 patients without PND underwent ICGA testing. The ICGA parameters, which included the time to maximum intensity (Tmax), the time from fluorescence onset to half the maximum intensity (T1/2), the time elapsed from the maximum intensity to 90% of the Imax and to 75% of the Imax (Td 90% and Td 75%, respectively) and the rate of intensity measured 60s after the Tmax to Imax (IR 60s), were compared between the patients with and without PND.

The Tmax, T1/2, Td 90%, Td 75% and IR 60s were significantly different between patients with and without PND. A value of Td 90% >30s was significantly correlated with the presence of PND (sensitivity: 0.85, specificity: 0.78).

ICGA tests can be used to quantitatively assess arteriovenous shunting in the limbs with PND. By measuring the value of the Td 90%, ICGA tests can estimate the presence of the arterio-venous shunting in PND, which might be helpful for assessing the progression of foot ulceration with diabetes, gangrene and the need for amputation.