One of the most important indications for performing a capillaroscopy is the differentiation between primary and secondary Raynaud's Syndrome. It is possible to examine with different kind of microscopes, which differ in different points like picture quality or price.

Before buying a microscope there should be thought about different aspects of the examination:

• – The region of interest. The capillaries have a diameter of about 8 μm. For a assessment a magnificiation of 100-200x is needed, for the overview the magnification should be about 50x.

• – Measurement. Beside of quantitative statements for example about the architecture of the vessels there should be a possibility of performing measurements like the number of capillaries/mm or the diameter of the vessels.

• – Documentation. All parts of the examination have to be stored and assigned to the patient and the case.

• – Practical aspects. The more often the examanitaion is performed, the more important will become practical aspects.

Three different kind of microscopes are:

• – Stereo microscope.

  Advantages: Very good image quality, zooming in without problems, relatively easy to use.

  Disadvantages: no mobile device, in patients with contractures difficult to perform examinations, relatively high costs

• – Videocapillaroscopes:

  Advantages: Very good image quality, easy to use, “gold standard” for capillaroscopy.

  Disadvantages: No overview, no direct zooming in possible, relatively high costs.

• – USB microscopes:

  Advantages: low costs, zooming in without problems, easy to use.

  Disadvantages: limited picture quality, documentation laborious

The selection of a capillaroscopic device depends on different preconditions which should be cleared up before buying the device. The price range differs between 100 and about 10000€.

Literature

1. Cutolo M et al.: Raynaud's phenomenon and the role of capillaroscopy. Arthritis Rheum 2003; 48: 3023-3030

2. Sander O et al.: Kapillarmikroskopie: Durchführung und Nomenklatur. Z Rheumatol 2010; 69: 253-262

3. Hermann W, Meier FMP, Müller-Ladner U: Reichen weniger als 100 Euro für ein Kapillarmikroskop? Z Rheumatol 2013.72:520-522

Disclosure of Interest None declared

DOI 10.1136/annrheumdis-2014-eular.6131