Table 1: Videocapillaroscopic criteria.

Videocapillaroscopic parametersCriteria

Distribution of the capillaries
 RegularHomogenous distribution of capillaries
 AlteredNonhomogenous distribution of capillaries
Density of the capillaries
 Normal9–13 capillaries/mm
 Increased>13 capillaries/mm
 Decreased<9 capillaries/mm or avascular area
Diameter of the capillaries
 NormalThe diameter of the afferent limb (6 to 19 μm) and the diameter of the efferent limb (8–20 μm), venous limb width ratio: arterial limb no greater than 2 : 1
 Enlargement of the top part of the loopDiameter of the limbs larger than average
 Enlargement of the efferent limbDiameter of the limbs larger than average
Length of the capillaries
 NormalApproximately 400 μm
 Elongated>750 μm
Extravasation
 AbsentNo extravasations
 SinglePresent in 1-2 fingers
 MultiplePresent in >2 fingers
Subpapillary venular plexus visibility
 Invisible
 1-2 fingersVisible in 1-2 fingers
 >2 fingersVisible in >2 fingers
Background colour
 Pale
 Pink
 Reddish
Morphology of the capillaries
 NormalAppearance like an inverted letter U
 Tortuous capillaries—regular appearanceSingle crossovers
 Tortuous capillaries—irregular appearanceMultiple crossovers or appearance like “treble clef” loop, “antler” loop, “trefoil” loop or meandering appearance with single/multiple crossovers
The number of tortuous capillaries
 Single<5 at least in two fingers
 Multiple>5 at least in two fingers
Branching capillaries
 PresentAt least one such loop in two fingers
Coiled capillaries
 PresentAt least one such loop in two fingers
Features of the capillary neoformation
 PresentThin, branching from one limb, or thin interconnection between the limbs (at least one such loop in two fingers)