Capillaroscopic technique and clinical examination

Nail fold videocapillaroscopy represents the safest non invasive, less expensive and reliable method to analyze microvascular abnormalities and the findings can be scored and quantified.

Clinical examination

Morphological evaluation of skin capillaries is generally performed at the nailfold because this area is easily accessible for examination, and the major axis of the capillaries is parallel to the skin surface.

Each subject must remain in the test room for a minimum of 15 min before the nailfold analysis, and the room temperature should be maintained at 20–22C. Usually at least 8 fingers should be examined. Fingers affected by recent local trauma are not analysed.

However, the most accurate morphological assessments are commonly performed on the fourth and fifth fingers, because of the greater transparency of the skin on these fingers.

Instruments

Morphological examination of capillaries can be performed by viewing the skin at low power (5±100x) through a simple light microscope or an opthalmoscope.In clinical practice, skin capillaries are generally observed through an incident light Microscope or videocapillaroscopic microcamera. However, nailfold capillary microscopy can be performed by means of a series of instruments including an ophthalmoscope, a dermatoscope and a stereomicroscope.

At present, videocapillaroscopic analysis is considered to be the most sophisticated tool to investigate the microvasculature, and may also detect blood flow at the level of the microvessels.