High prevalence of capillary abnormalities in patients with diabetes and association with retinopathy

Aims To investigate the presence of capillary abnormalities in patients with Type 1 and Type 2 diabetes using nailfold videocapillaroscopy and to evaluate the possible correlation with the typical diabetes mellitus microangiopathic lesions detectable in retinal blood vessels. Methods Forty-nine patients with diabetes mellitus (21 with Type 1 and 28 with Type 2 diabetes) and 39 subjects without diabetes were enrolled. Ophthalmoscopy was performed on all patients and was followed by retinal fluorangiography when indicated. Subjects underwent nailfold videocapillaroscopy to evaluate density, length, morphology and distribution of capillary loops, presence of ectasia, microbleedings and blood flow modifications. A score (0-3) was applied to quantify features of nailfold videocapillaroscopy. Results Subjects with diabetes showed a significantly increased (P = 0.0001) nailfold videocapillaroscopy score and significantly greater alterations of capillary length (P = 0.004), distribution (P = 0.02), morphology (P = 0.0001), density (P = 0.02) and flux (P = 0.004), as well as presence of ectasic loops (P = 0.009) and of oedema/exudates (P = 0.03) compared with control subjects. In addition, patients with Type 1 diabetes had a significantly higher score (P = 0.01) and greater morphologic alterations (P = 0.03) compared with subjects with Type 2 diabetes. Nailfold videocapillaroscopy score also showed a positive correlation with retinopathy, detected by both ophthalmoscopy (P = 0.0001) and fluorangiography (P = 0.02), independently from sex, age, type of diabetes and all potential confounders. Moreover, nailfold videocapillaroscopy was capable of identifying alterations in almost 50% of patients with diabetes without retinopathy. Conclusions A high prevalence of nailfold capillary changes is detected in patients with diabetes using nailfold videocapillaroscopy. These abnormalities tightly correlate with retinal damage and may be expression of a generalized microvessel involvement in both Type 1 and Type 2 diabetes.