Video-microscopy is a video-imaging system which permits direct visual
ization of the skin surface and capillaries, by using a microscope att
ached to a camera, a video-recorder and a printer. This technique prov
ides information on the morphology of capillaries in vivo and has been
used both for research into normal skin microcirculation and as a cli
nical method to detect capillary changes in psoriasis and other skin d
iseases. The aim of this study was to evaluate the morphology of capil
laries in psoriatic plaques before and after treatment with tacalcitol
, a new topical vitamin D3 analogue. Clinical evaluation was made afte
r 3 and 6 weeks of therapy. After 3 weeks a reduction in erythema and
scaling was noted; and areas in which capillaries were less tortuous b
ecame evident. After 6 weeks, capillaries were less dilated and tortuo
us in the whole plaque and had lost the large and tortuous appearance
of active psoriasis.