The utility of USB microscope for assessment of Raynaud’s phenomenon patients in rheumatology practice

The aim of the study was to assess the utility of USB microscope (DinoLite) for evaluation of patients with primary and secondary Raynaud’s phenomenon (RP) in rheumatic diseases, , using magnification 200x. Methods: The study represents retrospective analysis of capillaroscopic images of 53 patients with RP – primary and secondary in the context of systemic sclerosis (SSc) or other rheumatic diseases i.e., undifferentiated connective tissue disease (UCTD), prescleroderma and systemic lupus erythematosus (SLE). Capillaroscopic images are obtained from 8 fingers (II÷V bilaterally) using USB microscope (DinoLite) at magnification 200x. Capillary diameters were measured (arterial, venous and apical loop) as well as the number of capillaries per millimeter and capillary length. The capillaroscopic images were categorized into the following groups i.e., 1. absence of microangiopathy: i) normal pattern, ii) nonspecific changes; 2. presence of microangiopathy i.e., “scleroderma/ scleroderma-like” pattern. Results: Images suitable for analysis with good visibility that permit analysis of the major capillaroscopic parameters were available in all patients (100%). Among 53 included patients, 14 patients were with SSc, 12 cases with primary RP, and 27 patients with secondary RP in other connective tissue diseases  (22 patients with UCTD, 1 – with prescleroderma and 4 patients with SLE). „Scleroderma“ pattern was detected in 11 patients with SSc and in all these cases the capillaroscopic images were classifiable into one of the three distinct validated phases i.e., “early”, ”active” and ”late”. Presence of microvascular changes type “scleroderma-like” pattern was detected also in 17 among 27 patients with other connective tissue diseases. In primary RP patients, capillaroscopy revealed either normal pattern or nonspecific findings, but without features of microangiopathy. Conclusion: Capillaroscopic images of good quality, which could be analyzed and interpreted, are usually obtained using USB microscope. This permits evaluation of the major capillaroscopic parameters including quantitative measurement of the capillary diameters, capillary density and length. Assessment of the degree of microvascular changes i.e., staging of microangiopathy is also applicable and was possible in all cases with microangiopathy. The available software although less sophisticated vs those of videocapillaroscopes, providess the opportunity for adequate analysis of capillaroscopic parameters. The images obtained via USB microscope using magnification 200x are easily classified into “scleroderma”/“scleroderma-like” pattern, non-specific changes and normal findings using also the software of the device. Thus, USB microscopes using standard, 200x magnification could be suggested as an alternative of videocapillaroscopes in every day rheumatology practice especially in low-budget cases.